Plant Protection Science, 2002 (vol. 38), SI 2 - 6th Conf EFPP

Special Issue - DISEASE RESISTANCE IN PLANT PATHOLOGY, 6^th Conference of European Foundation for Plant Pathology, Prague, Czech Republic, 8-14 September 2002Second part

editors

Plant Protect. Sci., 2002, 38(11):i-viii | DOI: 10.17221/10621-PPS  

Detection of Peach latent mosaic viroid by PCR

P. Ryšánek, M. Zouhar, M. Hassan

Plant Protect. Sci., 2002, 38(11):249-251 | DOI: 10.17221/10458-PPS  

Peach latent mosaic viroid (PLMVd) is widespread in peach all over the world. It has never been reported from the Czech Republic. That is why we adapted specific and sensitive method for its detection, PCR, to be able to prove its possible occurrence and for certification purposes. Primers PLMVdR, PLMVdF1 and PLMVdF2 were designed on the basis of published RNA sequences. Products of amplification are 208 and 114 bp long for PLMVdF1 and PLMVdF2, respectively. Four PLMVd isolates from Dr Di Serio (CNR Bari) were used as standards. Potato spindle tuber viroid and Hop latent viroid infected plant material and also healthy material...

Simplification of RNA preparation procedure for RT-PCR in detection of pome fruit tree viruses

J.K. Kundu

Plant Protect. Sci., 2002, 38(11):252-254 | DOI: 10.17221/10457-PPS  

A rapid, easy to handling and sensitive RNA preparation procedure, RNA release protocol was described here for the detection of Apple stem pitting virus (ASPV) and Apple stem grooving virus (ASGV) by RT-PCR. Comparing total RNA extraction protocol, RNA release protocol give raised similar rate of ASPV and ASGV detection within the field-grown apple cultivars. Among sampling plant tissues, the bud leaf and leaf (during blossom) were showed efficient tissues for the routine detection, regardless the using RNA preparation procedures.

Electronmicroscopic study of Beet soilborne pomovirus

P. Kudláčková, M. Zouhar, P. Ryšánek

Plant Protect. Sci., 2002, 38(11):255-257 | DOI: 10.17221/10459-PPS  

Beet soilborne pomovirus (BSBV) was observed both in the sap and in tissues from local lesions on Chenopodium quinoa leaves after their embedding into acrylic resin LR White. Immunocapturing with polyclonal antibodies was used to enhance number of particles on grids and immunolabelling by colloidal gold was used for better visibility of virus particles in tissues. BSBV has rod-like particles of various length and it forms inclusions of several particles adhering side to side each to another.

Criteria for identification of Cauliflower mosaic virus's of the far eastern strains

R.V. Gnutova, V.F. Tolkach, Ju.V. Bogunov

Plant Protect. Sci., 2002, 38(11):258-260 | DOI: 10.17221/10461-PPS  

On the base of the present-day principles to classify plant viruses the identification of Cauliflower mosaic virus (CaMV), a new virus for the Russian Federation, is carried out. Biological properties of 7 isolates have been studied. Symptomatology, range of host-plants and physical properties of virions of studied strains differ. The least thermostable strain is CaMV-B3 (TIP - 75°C) and the highest TIP (85°C) is CaMV-B1. The highest virus concentration in sap was observed for CaMV-B2 (DEP - 10^-6), and lowest - CaMV-R1 (10^-1-10^-2). CaMV-B2 and CaMV-C2 lost infection during 4 days in room conditions, CaMV-B3...

Viruses of cucumber isolated from some regions of Ukraine

A. Ryzhkova, T.P. Shevchenko, I.G. Budzanivska, V.P. Polischuk

Plant Protect. Sci., 2002, 38(11):261-263 | DOI: 10.17221/10462-PPS  

Properties of viruses isolated from cucumbers in greenhouses of Ukraine are characterized in this article by electrophoresis, ELISA, electron microscopy, and immunoblotting.

Preliminary molecular characterization of some Citrus tristeza Closterovirus isolates infecting Croatian citrus

S. Černi, D. Škorić, M. Krajačić

Plant Protect. Sci., 2002, 38(11):264-266 | DOI: 10.17221/10460-PPS  

Citrus tristeza Closterovirus (CTV) is widespread in major citrus-growing regions of the world often causing destructive diseases. Citrus samples were taken from orchards in the Croatian coastal region. CTV was detected in two symptomless field trees of Satsuma mandarins and one diseased lemon tree. Double-stranded RNA was isolated from the field trees and the dsRNA patterns were compared in polyacrylamide gels. The same dsRNA extracts were used as templates in RT-PCR experiments amplifying the CTV coat protein sequence. Amplicons were subjected to SSCP and RFLP analyses. The results indicate greater similarity between CTV isolates from Satsuma...

Selection of RNA isolation method for molecular detection of grapevine viruses

P. Komínek

Plant Protect. Sci., 2002, 38(11):267-270 | DOI: 10.17221/10463-PPS  

Grapevines infected with Grapevine leafroll-associated virus-1 (GLRaV-1) and Grapevine leafroll-associated virus-3 (GLRaV-3) were selected. Total RNA was isolated from grapevine phloem tissue scrapped from dormant canes by three different methods: extraction with urea buffer followed with phenol-chloroform extraction, method using Concert^TM reagent (Invitrogen) followed with chloroform-isopropylalcohol extraction, and procedure using RNeasy Plant Mini Kit (Qiagen). The highest yield of RNA was obtained using Concert^TM reagent. If this RNA was used in RT-PCR, GLRaV-1 and GLRaV-3 were easily detected. From RNA...

Detection of the phytosanitary status of stone fruit cultivars under in vitro conditions in Hungary

I. Balla, É. Kriston, E. Tóth, W. Arthofer, V. Hanzer, M. Laimer

Plant Protect. Sci., 2002, 38(11):271-274 | DOI: 10.17221/10464-PPS  

Prunus species are prone to infections by a range of pathogens (LAIMER 2002). Stone fruit plantations are mainly affected by Plum pox virus (PPV), Prune dwarf virus (PDV), Prunus necrotic ringspot virus (PNRSV) and European Stone Fruit Yellows phytoplasma (ESFY). The production of elite plants of pathogen-free stone fruit cultivars includes the application of effective methods for the detection and elimination of the major stone fruit tree viruses and phytoplasmas. The method of micropropagation offers a quick possibility for breeders to introduce new cultivars into the production. Virus testing by molecular...

Genetic variability between different isolates of Potato mop-top virus (PMTV)

P. Rosecká, T. Moravec, M. Filigarová, P. Dědič, N. Čeřovská

Plant Protect. Sci., 2002, 38(11):275-277 | DOI: 10.17221/10465-PPS  

We determined partial nucleotide sequences of several different field isolates of PMTV with well-characterized biological properties from the Czech Republic and Denmark. Subsequently we were trying to elucidate the correlation between nucleotide sequences of various isolates, their biological properties and geographical origin. From the comparison with other known sequences we can conclude, that PMTV genome is relatively conserved.

Biological and molecular characterization of various isolates of Potato virus Y-N (PVY-N) strain group

J. Ptáček, P. Dědič, J. Matoušek

Plant Protect. Sci., 2002, 38(11):278-280 | DOI: 10.17221/10469-PPS  

Fourteen Potato virus Y (PVY) isolates were characterized. They represented PVYN strain only. However, application of serological and molecular genetic methods led to a more complicated characterization. For example, five isolates induced necrotic symptoms on tobacco plants typical of PVY^N, despite reacting as PVY^O serologically. Moreover, the PVY isolates were not identical according to molecular genetic properties. Typical PVY^NTN PCR products were observed for 11 isolates, but four of them (Hr220-5, Hr387-7, Nord 242 and Syn1Scot) did not produce potato tuber necrotic symptoms in infected cultivars. An immunocapture...

Susceptibility of Austrian apricot and peach cultivars to

S. Richter

Plant Protect. Sci., 2002, 38(11):281-284 | DOI: 10.17221/10467-PPS  

1548 stone fruit trees (1435 trees of P. armeniaca, 113 trees of P. persica) were examined by PCR for ESFY to get information on spread and susceptibility of cultivars and rootstocks used in Austrian stone fruit production. Cultivar susceptibility seems to be less important for tolerance to ESFY than rootstock resistance. Apricot cultivars on rootstocks of myrobalan, commonly used in Austria, are more infected than cultivars on plum rootstocks. Data on peach and apricot rootstocks are not representative as both are not commonly used in Austrian apricot production. In addition, the presence of peroxidase activity in shoot sieve tubes of infected...

Weed hosts of phytoplasmas in the Czech Republic

P. Válová, R. Fialová, M. Navrátil, J. Fránová, M. Šimková, J. Nebesářová

Plant Protect. Sci., 2002, 38(11):285-287 | DOI: 10.17221/10468-PPS  

The research was focused on wild plants that represent possible sources of phytoplasma infection. Thirteen species of wild herbaceous plants with symptoms of shoot proliferation, phyllody, virescence, sterility or yellowing have been collected from different locations of the Czech Republic. To detect and identify phytoplasmas, plants were subjected to electron microscopy, fluorescence microscopy, PCR, and RFLP analysis. There were phytoplasma positive species: Matricaria chamomilla, Plantago lanceolata, Plantago media, Silene latifolia ssp. alba, Stellaria media, Taraxacum officinale, Thlaspi arvense, Tragopogon pratensis, Trifolium pratense, Trifolium...

Genotypic characterisation of the Erwinia genus by PCR-RFLP analysis of rpoS gene

M. Waleron, K. Waleron, E. Łojkowska

Plant Protect. Sci., 2002, 38(11):288-290 | DOI: 10.17221/10470-PPS  

Genotypic characterisation of the members of the genus Erwinia, based on the PCR-RFLP analysis of a fragment of the rpoS gene was done. PCR primers deduced from described rpoS gene sequences of E. carotovora allowed the amplification of about 880 bp DNA fragments from all tested Erwinia species. The rpoS fragments, amplified from 20 species of the studied Erwinia genus, were compared by RFLP analysis with 4 enzymes (AluI, Hin6I, HinfI, and Tru1I). Restriction analysis allowed drawing 63 common profiles of RFLP products for all tested Erwinia. From 1 to 3 specific...

Immunochemical, biochemical and pathogenic properties of fluidal and intermediate strains of Clavibacter michiganensis subsp. sepedonicus

B. Kokošková, R. Jeřabková

Plant Protect. Sci., 2002, 38(11):291-293 | DOI: 10.17221/10471-PPS  

Clavibacter michiganensis subsp. sepedonicus (Cms), causing ring rot of potato, is a quarantine bacterium. According to colony morphology, Cms occurs mostly as fluidal (smooth), but sometime as intermediate (rough, i.e. less fluidal) variants, too. Commercial monoclonal antibodies (Agdia, USA) were used for determination of 40 Cms strains representing both forms. All Cms strains were reliably identified by IFAS, but atypical cells were sometime recorded in population of intermediate strains. The fluidal Cms strains were more reliably identified using DAS-ELISA and the Biolog GP MicroPlate System^TM than...

Detection of bacterial wilt pathogen of lucerne by PCR

M. Bryxiová, V. Kůdela

Plant Protect. Sci., 2002, 38(11):294-296 | DOI: 10.17221/10472-PPS  

A polymerase chain reaction (PCR) based assay was compared with assay involving traditional microbiological tests to detect and identify Clavibacter michiganensis subsp. insidiosus (Cmi) inside plant tissues following artificial inoculations. Primers for Cmi detection were selected from the Cmi insertion sequence IS 1122. External disease symptoms on the tops and histological symptoms on the cross-sections of the roots were evaluated visually and microscopically during two years after inoculation. Extracts were prepared from samples collected from the tops and roots of lucerne plants for both PCR and microbiological analyses. Colonies...

Characterization by RAPD-PCR of races of Fusarium oxysporum f.sp. ciceri infecting chickpea

N.M. Abou-Zeid, H. Halila, Khalil M.S.

Plant Protect. Sci., 2002, 38(11):297-301 | DOI: 10.17221/10475-PPS  

Isolates of Fusarium oxysporum f.sp. ciceri from chickpea (Cicer arietnum L.) can be characterized as races and wilt and yellowing pathotypes by pathogenicity tests on varieties of differentials chickpea. This study shows that, DNA bands generated by RAPD-PCR can be used to assign Fusarium oxysporum f.sp. ciceri isolates to pathotype and pathogenic race.

Race structure of Pyrenophora tritici-repentis isolates obtained from wheat in South America

A. Shaukat, L.J. Francl

Plant Protect. Sci., 2002, 38(11):302-304 | DOI: 10.17221/10473-PPS  

Knowledge of genetic variation in a pathogen population contributes to breeding for disease resistance. The fungus Pyrenophora tritici-repentis, cause of tan spot of wheat, is an important foliar pathogen worldwide. Currently, eight races have been identified in the fungal population prevalent on wheat and alternative hosts. Races 1 through 6 have been observed in North America. However, the fungal population from South America has not been characterized as to race. In this study, 48 single-spore isolates of P. tritici-repentis, recovered from wheat, were obtained from Argentina (10), Brazil (23), and Uruguay (15). Isolates were tested by...

Trichoderma polysporum as possible weak pathogen of tulip bulbs and roots

A. Piwoni

Plant Protect. Sci., 2002, 38(11):305-307 | DOI: 10.17221/10474-PPS  

In the spring 2000, on tulip plantations in south-eastern Poland, spots of died-off plants were observed. The inhibited growth, wilting of leaves and yellowish necrosis on roots and scales surface occurred especially in low-lying areas. Mycological analysis indicated the presence of Trichoderma polysporum (Link ex Pers.) Rifai on the bulbs and roots of all tested plant samples. Pathogenicity test of 7 T. polysporum isolates was carried out on forced tulips cv. Merry Christmas in flower pots. After flowering, brownish necrosis (covering 5-30% of the surface) on the bulbs and roots were observed, as well as white-yellowish mycelium...

Fusarium fungi as a pathogen causing hop wilt

J. Sabo, T. Đurić, S. Jasnić

Plant Protect. Sci., 2002, 38(11):308-310 | DOI: 10.17221/10476-PPS  

Foliar chlorosis and wilting of plants have been noticed in many hop gardens around the Vojvodina Province, Yugoslavia. Fusarium fungi have been isolated most frequently from samples of infected plants. They appear to be predominantly responsible for the observed infections. The fungi first colonize the underground plants parts (roots, crown and rootstocks) and the basal part of the stem, from where disperse and attack the neighboring vascular tissues. The interrupted delivery of water and nutrients to the terminal plant parts causes chlorosis, necrosis and wilting first of the apical leaves and then of lower leaves. The infected bins are...

Some characteristics of Gaeumannomyces graminis var. tritici originated from Poznań region

Z. Weber

Plant Protect. Sci., 2002, 38(11):311-318 | DOI: 10.17221/10477-PPS

Gaeumannomyces graminis var. tritici 39 isolates originated from Poznań region were used. Mycelium linear growth of the isolates varied from 3.1 to 7.3 mm/day. Variability of the isolates in pathogenicity was high and their susceptibility to fungicide Latitude 125 FS was very high. Mycelium linear growth rate was not correlated with both pathogenicity and susceptibility to the fungicide of the pathogen isolates.

Application of molecular methods for characterization of Botrytis fabae and Botrytis cinerea of faba bean

N.M. Abou-Zeid, I.H. Dorriah, Marwa A.A.

Plant Protect. Sci., 2002, 38(11):314-318 | DOI: 10.17221/10479-PPS  

Application of the RAPD methods allowed to clearly characterization of isolates of Botrytis fabae and isolates of B. cinerea. Results from RAPD-PCR analysis indicate different groups. Clusters were related with groups based on conidial morphology, morphological characters of the isolates of Botrytis spp.

Fungi settling seedlings of Stewartia pseudocamelia (Max.)

I. Gajda, H. Kurzawińska, P. Muras

Plant Protect. Sci., 2002, 38(11):319-321 | DOI: 10.17221/10478-PPS  

Stewartia pseudocamelia is one of more attractive of ornamental bushes. The main of decorative quality are: ornamental flowers, non-typical florescence (from end of June to August), original bark and attractive overcolouring of leaves in autumn season. Apart diseases affected Stewartia during vegetation period, the most dangerous are those which infest seedlings. The total number of 132 colonies of fungi were obtained from the sore seedlings of Stewartia. The isolates represented 19 species of thirteen genera. The most dominated of them were fungi of species: Cladosporium cladosporioides, Cylindrocarpon radicicola, Fusarium avenaceum...

Some pathogenic properties of Rhizoctonia solani to sugar beet seedlings

E.B. Moliszewska, J.H.M. Schneider

Plant Protect. Sci., 2002, 38(11):322-324 | DOI: 10.17221/10480-PPS  

Rhizoctonia solani causes various diseases in many crops world wide, it also causes losses in sugar beet grown in Poland and the Netherlands. In this research three isolates of R. solani was tested, two AG5 and one AG4. They differed in pathogenic activity in field and laboratory tests. The AG5 isolates were weak pathogenic but caused the decrease of cotyledons and first pair of leaves dimension. The AG4 isolate caused totally pre-emergence damping-off and its activity was the result of mycelium colonization ability and fungus metabolites activity.

From researches on the healthiness of gladiolus (Gladiolus sp. L.) corms in reproduction crops

E. Budzikur-Ramza, M. Bartyńska

Plant Protect. Sci., 2002, 38(11):325-328 | DOI: 10.17221/10481-PPS  

The results of laboratory and field tests are presented. An effect of the quality of vegetative reproduction material of gladiolus cultivar's Wars on spouting and growing of young plants as well as on the healthiness and quality of progeny corms are analysed. In addition, corm diseases are diagnosed and corresponding pathogens are identified.

Effect of fungicides on the growth of fungi isolated from in vitro propagated fruit-bearing plants

M. Kowalik, M. Gródek

Plant Protect. Sci., 2002, 38(11):329-331 | DOI: 10.17221/10482-PPS  

The aim of the work was to determine the effect of fungicides: Topsin M 70 WG, Bravo 500 SC, and Sportak 45 EC in two concentrations on the growth of fungi: Aspergillus niger, Epicoccum purpurascens, Cladosporium sphaerospermum, Mortierella isabellina and Penicillium verrucosum var. verrucosum on PDA and Murashige-Skoog medium (MS). The smallest index of linear growth rate of the fungi had Topsin M 70 WG for fungi: E. purpurascens and P. verrucosum var. verrucosum on PDA and MS medium and for M. isabellina and C. sphaerospermum on MS in concentrations of 71.42 mg/l and 107.13 mg/l. The highest index...

Fungal diseases of chickpea (Cicer arietinum L.) cultivated in the south region of Poland

S. Mazur, J. Nawrocki, J. Kućmierz

Plant Protect. Sci., 2002, 38(11):332-335 | DOI: 10.17221/10483-PPS  

The investigations carried out in the last years showed that weather conditions were conductive to growth of chickpea (Cicer arietinum L.) in Poland. Our experiments started since 2000 on two cultivars Myles and Sanford. Evans replaced cv. Sanford in second year. The results pointed to the cv. Myles as generally healthiest and the percentage of infested plants was 3.2% in the first year and 0.92% in the next year. The experiment showed that the most important threats for plants during vegetation season were fungi from the genus Fusarium and Rhizoctonia solani, isolated most often from roots. The basal parts of the stems affected mainly Alternaria...

Influence of nitrogen fertilizing on occurrence of fungi infecting parsley seedling roots (Petroselinum sativum Hoffm.)

J. Nawrocki, S. Mazur, J. Kućmierz

Plant Protect. Sci., 2002, 38(11):336-339 | DOI: 10.17221/10484-PPS  

The three years experiments based on parsley roots of cultivars: Omega, Berlińska and Vistula. Nitrogen fertilizer was used in different levels (0, 100, 200, 300 and 400 kg/ha). Results of autumn analysis indicate that differentiated nitrogen fertilizing has no significant effect on health status of parsley roots. Spring examinations showed increase percentage of ill roots. Lower root infestation of each cultivar was in the combinations: 100 kg/ha and control without nitrogen fertilizations. Omega showed the best soundness. Experiments indicated that cultivar plays a more significant role than nitrogen fertilizing level. From ill parsley roots, the...

Epidemiology of Septoria leaf blotch on spring triticale in West Lithuania

D. JANUŠAUSKAITÉ

Plant Protect. Sci., 2002, 38(11):338-390 | DOI: 10.17221/10502-PPS  

The effects of environmental conditions on the dynamics of Septoria leaf blotch, Septoria nodorum (Berk.) E. Castell et. Germano, incidence and severity on the spring triticale cv. Gabo were studied in 2000 and 2001 in littoral lowland of Lithuania. Disease assessments were carried out once a week from GS 31-32 to GS 81-83 on the three primary leaves. At milk ripening stage (GS 75) the incidence of Septoria on F leaves reached 44.9% in 2000 and 97.7% in 2001. The disease severity was 3.5% in the first year, and 11.5% in the second year. Comparison of 2 years' data revealed that whether conditions had a marked effect on the manner of disease...

Monitoring of incidence and determination of fungi on caraway, fennel, coriander and anise, consideration of disease importance and possibility of chemical protection

L. Odstrčilová, M. Ondřej, B. Kocourková, G. Růžičková

Plant Protect. Sci., 2002, 38(11):340-343 | DOI: 10.17221/10485-PPS  

The incidence of fungi on caraway (Carum carvi L.), fennel (Foeniculum vulgare Mill.), coriander (Coriandrum sativum L.) and anise (Pimpinella anisum L.) was observed on several localities in the Czech Republic. Incidence of 26 parasitic and saprophytic fungi were found on fennel, 35 species on coriander, 21 species on anise and 34 species on caraway. Small plot trials of spices were evaluated during the whole growing season. The fungicides in caraway were applied in different growth stages. The test results showed high effectiveness of autumn and early spring applications on the most dangerous pathogen of caraway - Mycocentrospora...

investigation of fungi infesting the caraway seeds (Carum carvi L.) in the south region of Poland

A. Szczeponek, S. Mazur

Plant Protect. Sci., 2002, 38(11):344-346 | DOI: 10.17221/10486-PPS  

Studies on the incidence the caraway seeds for pathogen infestation and test the pathogenicity of isolated fungi to caraway seedlings were carried out. A total of 383 fungi were isolated from seeds with evident symptoms of disease and without symptoms of disease. In this case a complex of different pathogens was isolated, among which Alternaria, Fusarium and Epicoccum were predominant. Pathogenicity assay on caraway seedlings was performed using isolates originating from caraway seeds. All tested fungi showed a very high aggressiveness in pathogenicity test.

Fungi colonizing various organs of lemon balm (Melissa officinalis L.) cultivated in South-East Poland

Z. Machowicz-Stefaniak, E. Zalewska, B. Zimowska

Plant Protect. Sci., 2002, 38(11):347-350 | DOI: 10.17221/10487-PPS  

On one-year-old and two-year-old plantations of lemon balm observations on the occurrence of plants showing symptoms of fungal diseases were made in 1998-2001. Many fungi were isolated from roots, stem bases and leaves separately on mineral medium. Species of Fusarium, Phoma and Rhizoctonia solani were obtained from the roots and stem bases whereas Alternaria alternata, Phoma spp., Septoria melissae and Botrytis cinerea were most often isolated from the leaves showing symptoms of necrosis.

Detection of root knot nematode Meloidogyne incognita by PCR

B. Tesařová, M. Zouhar, J. Lucinio, P. Ryšánek

Plant Protect. Sci., 2002, 38(11):351-353 | DOI: 10.17221/10491-PPS  

It is indispensable to have accurate and speedy method of nematodes detection considering their great deal of malignancy nematodes. For identification of Meloidogyne incognita genetic primers were designed and the procedure was attested by Polymerase Chain Reaction.

Morphological characteristics and distribution of Globodera species in Slovenia

G. Urek, S. Širca, V. Meglič

Plant Protect. Sci., 2002, 38(11):354-357 | DOI: 10.17221/10488-PPS  

Surveillance on cyst nematodes in Slovenia started already in 1963. We have found Globodera rostochiensis for the first time in 1971 and for the second time in 1975 (two cysts). In 1999 cysts of yellow potato cyst nematode were found again. A small hot spot was detected along the Slovene Austrian border. Cysts of Globodera rostochiensis were extracted from samples taken in 1.6 hectare field. In 2001 we surveyed 194 fields with the surface of 468.29 ha. We discovered another hot spot of Globodera rostochiensis in the Central Slovenia. Cysts of Globodera achilleae are seldom discovered in Slovenia. During the period between 1980 and...

Using point mutations in rDNA for differentiation of bioraces of Ditylenchus dipsaci from the Czech Republic

M. Zouhar, M. Marek, J. Lucinio, P. Ryšánek

Plant Protect. Sci., 2002, 38(11):358-360 | DOI: 10.17221/10490-PPS  

Ditylenchus dipsaci is one of the most harmful parasitic nematodes in Central Europe. It is able to survive for long time in soil without its host plants and that is why it belongs to organisms with quarantine importance. Nothing is known about D. dipsaci distribution in the Czech Republic. The aim of the study was to collect samples of D. dipsaci from the Czech Republic and to identify them by molecular methods. Region of rDNA including 3'end of 18 S gene, ITS1, 5,8 S gene, ITS2 and 5'end of 26 S gene was amplified using general primers designed according to the DNA sequence of Caenorhabditis elegans....

Communities of bacteria and fungi occurring in the rhizosphere of winter wheat

E. Patkowska, D. Pięta, A. Pastucha

Plant Protect. Sci., 2002, 38(11):361-363 | DOI: 10.17221/10489-PPS  

The purpose of the present studies was to establish the species composition of fungi occurring on the underground parts of winter wheat, Kobra cv. and to determine the quantitative and qualitative composition of microorganisms developing in the rhizosphere of this plant. The mycological analysis of the infected roots and the stem base of winter wheat gave 320 fungi isolates. Fusarium spp. were most frequently isolated, and their proportion was 64.7% of all the fungi. This genus was represented by F. avenaceum, F. culmorum, F. equiseti, F. graminearum, F. oxysporum and F. solani. Among these species the dominating ones were...

Annual herbs - possible reservoirs of sharka disease?

Ľ. Slováková, I. Dávidová

Plant Protect. Sci., 2002, 38(11):364-366 | DOI: 10.17221/10492-PPS  

Nineteen annuals - herbaceous indicators - were used for elucidation of Plum pox potyvirus seed transmission possibility after artificial inoculation with 9 different naturally infected PPV M and D strain sources. The seeds of positive enzyme-linked immunosorbent assay (ELISA) tested herbaceous indicators were collected and planted for germination. Successful seed transmission was detected after ELISA in 3 weeks old plants as follows: Nicotiana benthamiana 3.75% (source of PPV M Prunus domestica L. cv. unknown); N. clevelandii 3.5% (source of PPV M P. armeniaca (L.) Batsch cv. V 66052); N. benthamiana 8.42% and N. acuminata...

Occurrence of nepoviruses in small fruits and fruit trees in Slovakia

V. Šubíková, E. Kollerová, Ľ. Slováková

Plant Protect. Sci., 2002, 38(11):367-369 | DOI: 10.17221/10493-PPS  

A survey of nepoviruses in small fruits and fruit trees in thirteen localities of Slovakia was undertaken during the last three years. The samples of spontaneously infected small fruits and fruit trees with symptoms such as leaf yellowing, mottling, chlorotic spotting, vein clearing, chlorosis, dwarfing, and in some cases even plant dying, were analysed. Virus identification in collected samples from affected crops was performed by ELISA using polyclonal antibodies. The following quarantine nepoviruses were detected: Tobacco ringspot nepovirus, Tomato ringspot nepovirus, Tomato black ring nepovirus, Raspberry ringspot nepovirus, Cherry leafroll...

Population dynamics of the leafhopper Psammotettix alienus Dahlb. and two-year investigations into the occurrence of Wheat dwarf virus (WDV) in crops of winter barley located in the Middle German Dry Region, Germany

S. Mehner, B. Manurung, D. Schmidt, M. Grüntzig, W. Witsack, E. Fuchs

Plant Protect. Sci., 2002, 38(11):370-374 | DOI: 10.17221/10494-PPS  

From 2000 to 2001 the population dynamics of Psammotettix alienus Dahlb. were recorded using a sweep-net or a biocoenometer. The investigations were carried out in Zscherben near Halle (Middle German Dry Region). The imagines of the first generation of P. alienus could be observed for the first time at the beginning of May (2000) and at the end of May (2001), respectively. According to our results, in this area three generations of P. alienus are developed. In both years of our observations the barley-strain of Wheat dwarf virus (WDV) occurred. The main important infections appeared in autumn. Furthermore, during...

Orchid viruses of natural Ukrainian flora

A.V. Koroteyeva, V.P. Polischuk

Plant Protect. Sci., 2002, 38(11):375-377 | DOI: 10.17221/10495-PPS  

Virus infection greatly affects to the normal growth and reproductive intensity of orchid species in greenhouses. Peculiarities of ornamental orchid viruses has become known in different countries of the world while there is nothing known about orchid virus infection in natural flora of Europe, for example in Ukraine. After extensive virus detection of natural orchids of Ukraine (Carpathians, Crimea), some viruses infecting these plants in their natural inhabitance were determined.

Genetic variation between Colletotrichum lindemuthianum isolates

K.I. Ansari, N. Palacios, C. Araya, T. Langin, D. Egan, F.M. Doohan

Plant Protect. Sci., 2002, 38(11):378-380 | DOI: 10.17221/10496-PPS  

We characterized the genetic diversity of seventy-three C. lindemuthianum isolates collected from 10 different countries by Amplified Fragment Length Polymorphism (AFLP) analysis. The results of this research highlighted the fact that there is huge variation in the genetic diversity between isolates from different countries. The molecular profile of the isolates showed correlation with geographic origin of the isolates.

Tan spot development peculiarities in Latvia

B. Bankina

Plant Protect. Sci., 2002, 38(11):381-383 | DOI: 10.17221/10497-PPS  

Tan spot, caused by Pyrenophora tritici-repentis (Died.) Drechs., anamorph Drechslera tritici-repentis is one of the most important wheat diseases in the world, especially in the regions of intensive wheat growing. Tan spot had established for the first time in Latvia in 1994. Epidemic of this disease was observed in Latvia in 1998. Development of tan spot were investigated in field experiments at the Research and Training Farm "Peterlauki" of Latvia University of Agriculture in 1998-2001. Level of incidence and severity of tan spot differed depending on varieties and years. Severity of the disease was 16-71% in 1999; 0.1-5% in 2000 and 4-18%...

Dark leaf and pod spot (Alternaria brassicae) on oilseeds (Brassica napus) in Lithuania

I. Brazauskiene, E. Petraitiene

Plant Protect. Sci., 2002, 38(11):384-387 | DOI: 10.17221/10498-PPS  

Dark leaf and pod spot caused by Alternaria brassicae (Berk.) Sacc. is a serious problem both in winter and spring oilseed rape (Brassica napus L.) in Lithuania. According to ten years' data, the spread of this disease on winter oilseed rape siliques was 31.2-100%, and the severity 3.4-25.0%. The cultivars Ceres, Accord and Kasimir were used in the trials. Through the years 1997-2001 the incidence of Alternaria blight on spring oilseed rape (cv. Star and Maskot) was 94.5-100% and the severity 1.5-20.5%. Every year the severity of the disease was highly influenced by the meteorological conditions - precipitation and temperature. Fungicides,...

Morphotypes of Botrytis cinerea Pers.: Fr. in the conditions of Belarus

A.K. Khramtsov, A.S. Shukanov, V.D. Polyksenova

Plant Protect. Sci., 2002, 38(11):391-394 | DOI: 10.17221/10503-PPS  

Studies in all three agroclimatic regions of Belarus have allowed us to obtain more then 100 isolates of B. cinerea causing gray mold of many plants. The isolates were shown to belong to the three cultural-morphological groups such as mycelial, sporulating and sclerotial. Mycelial isolates (48.5%) concerned by some researchers as the high pathogenic group prevail over other two groups. Nutritive substrate was proved not to determine the formation of strictly definite morphotype. The rate of radial growth of B. cinerea colonies reveals no correlation with morphological peculiarities of these. Strict regularities in the forming of spores...

Distribution and pathogenic peculiarities of fungi of the Alternaria genus on vegetable crops in Lithuania

A. SHIDLAUSKIENÉ, E. SURVILIENÉ

Plant Protect. Sci., 2002, 38(11):395-398 | DOI: 10.17221/10504-PPS  

In 1999-2001 the investigation of Alternaria species on vegetable crops: cabbage, cucumber, tomato and carrot was carried out and fungi species were isolated from vegetables and substrata used for plant cultivation. Isolated micromycetes: Alternaria alternata, Alternaria tenuissima, Alternaria brassicae, Alternaria brassicicola, Alternaria cucurbitae, Alternaria dauci, Alternaria radicina and Alternaria solani differed in pathogenic peculiarities, frequency of occurrence and their various reaction to fungicides (a.s. azoxystrobin, dichlofluanid, Cooper hydroxide, mancozeb, propamocarb hydrochloride), plant activator Bion...

Investigation of biological peculiarities of Blumeriella jaapii

A. Valiushkaite

Plant Protect. Sci., 2002, 38(11):399-401 | DOI: 10.17221/10505-PPS  

Leaf spot pathogen is characterized as a highly developed parasite after investigation of development peculiarities of the fungus in pure culture and natural conditions. The degree of correlation depended on the medium. Impact of incubation temperature on Blumeriella jaapii (Rehm) Arx growth was different. Fungi colonies formed more intensively and their diameter increased significantly under higher temperature. Optimal conditions for the disease prevalence are 15-20°C and moisture. Relative humidity and precipitation influenced maturation of ascomycetes and discharge of ascospores (r = +0.89). Microscopic analysis of leaves showed...

Evaluation of fusarioses in selected grass species

B. Voženílková, F. Klimeš

Plant Protect. Sci., 2002, 38(11):402-405 | DOI: 10.17221/10506-PPS  

In the years 1999-2001 we observed the spread and harmful effects of pathogenic fungi causing the dying of some grass species in permanent grass growths. The most common and frequent cause of the dying (winter freezing injury) is the fungus Microdochium nivale known also as Fusarium nivale, or Gerlachia nivalis (imperfect stage) - snow mould. The evaluation was carried out in dominant species (Deschampsia cespitosa, Festuca rubra, Holcus mollis) in permanent grass growths in the central part of the Bohemian Forest (locality Zhůří (1050-1080 m a.s.l.). The experiment involved three treatments: (1) Mulched growth (mulched...

Comparison of multiplex real-time PCR and ergosterol assays in quantifying Heterobasidion annosum in planta

A.M. Hietala, M. Eikenes, M. Kvaalen, H. Solheim, C.G. Fossdal

Plant Protect. Sci., 2002, 38(11):406-407 | DOI: 10.17221/10507-PPS  

A quantitative multiplex real-time PCR procedure was developed to monitor the dynamics in Norway spruce-Heterobasidion annosum pathosystem. The assay reliably detected down to 1 pg of H. annosum DNA and 1 ng of host DNA in multiplex conditions. As a comparative method for quantifying fungal colonization, we applied the ergosterol assay. There was a very high correlation between the results obtained with the two methods, this strengthening the credibility of both assays. The advantages and disadvantages of these assays are discussed.

Occurrence and virulence of wheat yellow rust in Hungary during 1999-2001

K. Manninger

Plant Protect. Sci., 2002, 38(11):408-410 | DOI: 10.17221/10508-PPS  

The occurrence and virulence of wheat yellow rust in Hungary was studied in the period of 1999-2001. Yellow rust in Hungary occurred only in traces in 1999, strongly spread and reached epidemic level in Röjtökmuzsaj (West Hungary) in 2000, and the epidemic explosion was in the whole country in 2001. Surveys of yellow rust showed the importance of pathotypes, whose virulence spectra (virulent for Yr2, Yr3, Yr6, Yr7, Yr8, Yr9, Yr17, YrA+, YrCV, YrSD) were able to math the unknown resistance genes. Among 78 Hungarian and foreign cultivars 29 were strongly infected by yellow rust.

Biodiversity of rust fungi in the Šumava (Bohemian Forest) and in the Krkonoše (Giant Mountains), Czech Republic

J. Marková

Plant Protect. Sci., 2002, 38(11):411-414 | DOI: 10.17221/10509-PPS  

The occurrence and seasonal dynamics of rust fungi (Uredinales) on wild growing plants was investigated on eleven localities in the Bohemian Forest (Šumava Mts.) and on three localities in the Giant Mountains (Krkonoše Mts.). All studied localities are situated in the most strictly protected areas of the Czech National Parks (ecosystems of the mires, the glacial corries, and the arctic alpine tundra) that are considered the primary centres of biodiversity. The frequency of occurrence of the rust species is linked with the host plant diversity. It is also influenced by the human activity in specific places. The occurrence and the distribution...

Distribution of cucurbit powdery mildew species in the Czech Republic

E. Křístková, A. Lebeda, B. Sedláková, M. Duchoslav

Plant Protect. Sci., 2002, 38(11):415-416 | DOI: 10.17221/10511-PPS  

The occurrence of Erysiphe cichoracearum (Ec) and Sphaerotheca fuliginea (Sf), causal agents of cucurbit powdery mildewin the Czech Republic (CR) was studied in the period of 1995-2001. Nearly 800 leaf samples with disease symptomswere microscopically examined. Ec is the predominating species, detected on 98% of locations. It was accompanied by Sfon 24% of locations. The occurrence of Sf as the only powdery mildew species was proved on 2% of locations. Recentoccurrence of Sf in the CR corresponds with data on Sf fast spreading and prevailing on cucurbits in West and SouthEurope. However, Ec is the strongly predominating powdery mildew...

Comparison of two wheat powdery mildew differential sets in seedling tests

G. Vida, L. Szunics, M. Gál, O. Veisz, Z. Bedő

Plant Protect. Sci., 2002, 38(11):417-420 | DOI: 10.17221/10510-PPS  

Two wheat powdery mildew differential sets were tested in the seedling stage in the 2001/2002 season using 192 monoisolates. The data of genotypes carrying the same Pm gene in different genetic backgrounds were compared. Both varieties with gene Pm8 (Salzmünde14/44 and Disponent) were infected by all the isolates. Less than 10% of the isolates gave different responses on varieties with genes Pm2 and Pm3c (6 and 16, respectively). It is doubtful whether the degree of infection of genotypes carrying genes Pm1, Pm4b, Pm5, Pm6 or Pm7 can be compared, while it is completely impossible to compare the...

Septoria epidemics on wheat: combined use of visual assessment and PCR-based diagnostics to identify mechanisms of disease escape

B.A. Fraaije, D.J. Lovell, S. Baldwin

Plant Protect. Sci., 2002, 38(11):421-424 | DOI: 10.17221/10512-PPS  

The effect of crop height on the epidemics of Septoria tritici and Stagonospora nodorum was investigated using visual assessment and PCR-based assays. Based on the results of our study, the primary mechanism of disease escape in tall crops is through a reduction of spore arrival. Real-time PCR is an important tool to quantify spore arrival and can, in combination with visual assessment, identify factors involved in the onset and extent of disease development.

Development and ultrastructure observations of secondary hyphae of Podosphaera leucotricha on apple cultivars of varying susceptibility to powdery mildew

E. Rakhimova

Plant Protect. Sci., 2002, 38(11):425-428 | DOI: 10.17221/10513-PPS  

The development and ultrastructure feature of secondary hyphae of Podosphaera leucotricha were studied using light and electron microscopy. The percentage of development and length of secondary hyphae, differed in compatible and incompatible combinations. In compatible host-parasite combinations, hyphal cells of powdery mildew fungus contained a full complement of fungal organelles. There were differences of hyphal ultrastructure in compatible and incompatible host-parasite combinations, the main one was the appearance of dense material inside the nucleus, in the cytoplasm, and a few mitochondria.

Development of Colletotrichum acutatum in the foliar tissue of strawberry plants

F.T. Arroyo, F.J. Moreno, P. Daza, J. Torreblanca, G. García-Herdugo, B. De Los Santos, C. Barrau, C. Blanco, M. Porras, F. Romero

Plant Protect. Sci., 2002, 38(11):429-431 | DOI: 10.17221/10514-PPS  

Strawberry anthracnose, caused by Colletotrichum acutatum, is one of the most destructive disease of this crop throughout the world. Assymptomatic stages in the plant have been the aim of this work. Inoculated leaves samples were taken at different times and they were processed for scanner electron microscopy (SEM) and transmission electron microscopy (TEM). Conidial development on both surfaces leaves was determined. The ultrastructural study of fungus penetration into plant cell was characterized by the formation of vesicles over the fungus periphery and is a morphological parameter of the intense membranes traffic, also could be a evidence...

The role of gum induced by Fusarium oxysporum Schlecht. Snyd. et Hans. f.sp. tulipae Apt. in tulip bulbs on growth and development of the pathogen

A. Saniewska

Plant Protect. Sci., 2002, 38(11):432-435 | DOI: 10.17221/10515-PPS  

It was showed that gums induced by Fusarium oxysporum f.sp. tulipae in tulip bulbs applied to mineral Czapek-Dox Broth with Bacto Agar (CzDA) medium, containing sucrose substantially stimulated abundant growth of mycelium and sporulation of the pathogen. Addition of arabinose, xylose and their mixture, sugars occurring in tulip gum polysaccharide, to CzDA medium caused that mycelium was very sparse and sporulation was only slightly stimulated by arabinose. Mycelium growth on mineral CzDA medium without sucrose, was poor and sparse but addition of gum to the medium caused formation of abundant mycelium and increased sporulation of...

Preliminary evaluation of the effect of Ampelomyces quisqualis on the degree of plant infestation with selected Erysiphales species proposed as potential bioindicators

E. Sucharzewska, M. Dynowska

Plant Protect. Sci., 2002, 38(11):436-438 | DOI: 10.17221/10516-PPS  

In the year 2000 Ampelomyces quisqualis was noted, with various intensity, in north-eastern Poland on different species of Erysiphales selected as potential bioindicators of urban pollution. The results of observation of Erysiphe sordida (on Plantago major), Sphaeroteca erigerontis-canadensis (on Taraxacum officinale) and Microsphaera hypophylla (on Quercus robur) - susceptible species, and Microsphaera palczewskii (on Caragana arborescens) - a resistant species, suggest that A. quisqualis shows affinity to some hosts regardless of their individual reactions to...

Effect of cropping system on a fungal community colonizing seeds of fodder galega (Galega orientalis Lam.)

B. Cwalina-Ambroziak

Plant Protect. Sci., 2002, 38(11):439-441 | DOI: 10.17221/10517-PPS  

The fungal population colonizing the seeds of fodder galega cultivated in pure stand was greater than that cultivated in mixed stand. No significant differences were observed in the species composition of the obtained fungal colonies. In all analyzed combinations, Alternaria alternata was predominantly isolated from the seeds. Other saprophytic fungi were represented by the following species: Epicoccum purpurascens, Cladosporium cladosporioides as well as fungi representing genera Mucorales: Mucor hiemalis and Rhizopus nigricans. Among the pathogens, Botrytis cinerea was most often isolated. The...

Microorganisms colonising the rhizosphere of winter wheat protected with Impact Super 347 SC fungicide and Bion 50 WG plant resistance stimulator

U. Wachowska, B. Majchrzak

Plant Protect. Sci., 2002, 38(11):442-445 | DOI: 10.17221/10518-PPS  

In a field experiment, the effect of plant protection agents on fungal colonies colonising the rhizoplane and the rhizosphere of Elena winter wheat was determined. Impact super 347 SC (flutriafol and chlorotalonil) limited the number of fungi representing Trichoderma, promoted the growth of both fungi from the Fusarium gene and bacteria of Pseudomonas in addition to tricalcium phosphate hydrolysing bacteria. The plant resistance stimulator Bion 50 WG (acybenzolar-s-methyl) strongly reduced the population of Actinomycetales. Bacteria representing Azotobacter did not respond to the applied agents.

Oxidative burst and cell death induced by b-quercinin and zoospores of Phytophthora quercina in tobacco cell cultures

J. Koehl, E.F. Elstner, W. OßWALD, I. Heiser

Plant Protect. Sci., 2002, 38(11):446-448 | DOI: 10.17221/10519-PPS  

Mode of action of β-quercinin, a novel elicitin on tobacco cell suspension cultures (cvs. Bel B and Bel W3) was investigated by measuring the oxidative burst and cell death in these cell cultures. β-quercinin induced an oxidative burst comparable to that excited by zoospores from P. quercina. Adding superoxidedismutase, catalase and diphenyleneiodonium to elicited cell cultures, it could be demonstrated, that the induction of cell death in tobacco cell cultures is not correlated to the oxidative burst.

Changes in photosynthetic apparatus of tobacco leaves in conditions of virus infection and shortage of nitrogen

V.Z. Ulinets, V.P. Polischuk

Plant Protect. Sci., 2002, 38(11):449-451 | DOI: 10.17221/10520-PPS  

Data of the comparative investigation of the viral infection (TMV) and nitrogen starvation in the ratio of chlorophyll a/b, photochemical activity of PS I and PS II, pigment-protein structure of chloroplasts thylakoids and parameters of the fluorescence induction of tobacco leaves are presented. The changes of the structural and functional characteristics of the photosynthetic apparatus testify to negative influence of this factors on the function of both photosystems with primary inhibition of PS II.

Inhibition of Solanaceae plants by combined effect of increased concentrations of heavy metals and viral infection

I.G. Budzanivska, F. Demyanenko

Plant Protect. Sci., 2002, 38(11):452-454 | DOI: 10.17221/10521-PPS  

On plants of a Solanaceae family cultivated on a ground with increased concentrations of metals (Cu = 10; Pb = 21.5; Zn = 13.2 mg/kg) was shown both propagation and development depressing and decreasing of common protein. The superposition of a virus infection (TMV, PVX) results in considerable accumulation of viruses and early plants death. The contamination of soil by heavy metals results in plants propagation and development depressing, that in turn entails considerable development of viral and other infections resulting in crop losses.

Stress caused by plant virus infection in presence of heavy metals

A.V. Shevchenko, I.G. Budzanivska, T.P. Shevchenko, V.P. Polischuk

Plant Protect. Sci., 2002, 38(11):455-457 | DOI: 10.17221/10522-PPS  

Due to increased heavy metal content in Ukrainian soils, purpose of the work was to study relations between presence of heavy metals in soil and their effect on development of phytoviral infection. Experiments were conducted in Nicotiana tabacum - Potato virus X model system. Soluble salts of Cu, Zn and Pb were deposited in soil separately at the limiting concentrations simultaneously with virus infection of plants. Infected plants grown on usual soil showed symptoms of disease on 16 dpi as well as plants grown on soil with metals deposited. Contrary, combined effect of heavy metals and virus infection caused an increase of chlorophyll...

Functional studies on the role of reactive oxygen intermediates in the resistance of barley against powdery mildew

R. Hückelhoven, M. Trujillo, C. Dechert, H. Schultheiss, K.-H. Kogel

Plant Protect. Sci., 2002, 38(11):458-460 | DOI: 10.17221/10523-PPS  

The role of reactive oxygen intermediate (ROI) accumulation in resistance and susceptibility of plants to parasitic fungi is still little understood. We examined the spatial and temporal occurrence of different ROIs in barley after inoculation with the biotrophic fungus Blumeria graminis f.sp. hordei (Bgh, barley powdery mildew fungus). Using histochemical analyses, we collected correlative data indicating that H₂O₂ and O₂^*- play different roles in background penetration resistance to Bgh. To study the role of O₂^*- in detail, we isolated barley cDNAs encoding...

In planta and in vitro interactions between Phomopsis (Diaporthe) isolates and sunflower

A.M. Pennisi, M.R. Abenavoli, B. Maimone, L. Di Dio

Plant Protect. Sci., 2002, 38(11):461-465 | DOI: 10.17221/10524-PPS  

In this study, we determined the amount of H₂O₂ released by sunflower callus cultures challenged by both crude hyphal wall extracts and culture filtrates of 26 Phomopsis isolates from sunflower of worldwide origin (Argentina, France, Italy, Yugoslavia, Rumania). The amount of H₂O₂ released by callus cultures and the production time-course response, however, did not correlate with both the amount of electrolytes released by sunflower leaf disks treated with crude culture filtrates and the results of pathogenicity tests on sunflower seedlings. Only few isolates induced a time-course response indicative...

Side effect of iodosulfuron-methyl/Na + mefenpyr-diethyl and isoproturon on micromycetes on winter wheat

E. Prokinová, K. Patočková

Plant Protect. Sci., 2002, 38(11):466-468 | DOI: 10.17221/10525-PPS  

Side effect of two herbicides (iodosulfuron-methyl/Na + mefenpyr-diethyl = Husar and isoproturon = Tolkan) on micromycetes on winter wheat was study. Herbicide treatment reduced the whole number of fungi and number of genera in phyllosphere. It reduced number of the rhizosphere fungal genera, too. Population of Chrysosporium sp. markedly increased after Husar application, whereas population of Trichoderma harzianum was markedly reduced. Tested herbicides inhibited the development of Fusarium avenaceum on wheat leaves. Iodosulfuron-methyl/Na + mefenpyr-diethyl significantly reduced the growth of F. avenaceum in vitro.

Chitinases and endoglucanases synthesized in the infected barley leaves in the powdery mildew period sporulation

E. Hlinková, M. Bobák, P. Illéš

Plant Protect. Sci., 2002, 38(11):469-473 | DOI: 10.17221/10526-PPS  

In our work, we represent genetic, molecular and biochemical changes induced in the infected barley leaves induced in the period pathogen sporulation. We studied a presence of acidic β-1,3-endoglucanases and chitinases in an intracellular fluid isolated from primary barley leaves infected with two powdery mildew pathotypes carrying various virulence genes. In the period of pathogen sporulation acidic β-1,3-endoglucanases (Glu) and chitinases (Chi) isozymes were synthesized in two main groups. Non-specific, high molecular group of these enzymes with Mr > 200 kDa did not differ genetic differences between host and pathogen. Specific, low...

Albugo candida (white rust) suppresses resistance to downy mildew pathogens in Arabidopsis thaliana

Cooper A.J., A. Woods-Tör, E.B. Holub

Plant Protect. Sci., 2002, 38(11):474-476 | DOI: 10.17221/10527-PPS  

Arabidopsis thaliana accessions were inoculated with incompatible isolates of downy mildews, following pre-inoculation with compatible Albugo candida. Three isolates of Hyaloperonospora parasitica subsp. A. thaliana, an isolate of H. parasitica subsp. Brassica oleracea and one Bremia lactucae (lettuce) isolate were included. All downy mildews sporulated on A. thaliana, suggesting A. candida suppresses broad-spectrum downy mildew resistance. The white rust resistance gene, RAC5, is being investigated. The resistance phenotype associated with RAC5 seems...

Knock-down of the small G-protein RACB enhances penetration-resistance of barley against the powdery mildew fungus

H. Schultheiss, C. Dechert, K.-H. Kogel, R. Hückelhoven

Plant Protect. Sci., 2002, 38(11):477-479 | DOI: 10.17221/10528-PPS  

Small G-proteins (RAC and RHO) are known to be involved in regulation of superoxide (O₂^*-) production and the assembly of actin fibres. These processes are known to be crucial for accessibility and inaccessibility of barley cells to the biotrophic fungus Blumeria graminis f.sp. hordei (Bgh). Using a candidate RT-PCR approach six Rac-related cDNA-clones were isolated from barley. The transient knock-down of RacB led to a remarkably lower penetration efficiency of Bgh into susceptible barley lines (Mlo/Ror1). Surprisingly the inhibition of RacB expression had no effect in the...

Characterization of two closely linked soybean pgip genes and transcript regulation following pathogen infection and wounding

D. R Ovidio, S. Roberti, M. Melaragni, C. Capodicasa, L.S. Sella, F. Favaron

Plant Protect. Sci., 2002, 38(11):480-482 | DOI: 10.17221/10529-PPS  

Polygalacturonase-inhibiting protein (PGIP) is a plant cell wall protein that regulates the action of fungal endopolygalacturonases (PG) favouring the formation of oligogalacturonides active as elicitors of plant defense responses. We have isolated two novel soybean PGIP genes (Gmpgip1 and Gmpgip2) and their recognition specificities against fungal PGs have been tested by expressing them in Nicotiana benthamiana using the Potato virus X (PVX) as vector and in Escherichia coli. In both systems GmPGIP1 and GmPGIP2 accumulate but showed no activity against PGs. Transcript regulation of GmPGIP1 and GmPGIP2 showed that...

Isolation of differentially expressed genes involved in clubroot disease

A. Schuller, J. Ludwig-Müller

Plant Protect. Sci., 2002, 38(11):483-486 | DOI: 10.17221/10530-PPS  

The interaction between Plasmodiophora brassicae and its host Brassica rapa is investigated by two strategies. (1) IAA-conjugate hydrolases: Root hypertrophy in club root disease is dependent on increased auxin levels and these could result from auxin-conjugate hydrolysis. So far we isolated 5 different cDNA fragments out of various tissues which revealed high identity to IAR3/ILL5, ILL2, ILL3, ILL6 and ILR1 genes from Arabidopsis by comparison with database entries. (2) Random priming: Using this method, we have so far obtained 26 clones from clubroot tissue, from which several sequences may be components...

Promoter studies of chemically induced BCI-genes in the pathosystem barley - powdery mildew

U. Geldermann, G. Langen, K.-H. Kogel

Plant Protect. Sci., 2002, 38(11):487-488 | DOI: 10.17221/10531-PPS  

Chemical resistance inducers like BTH (S-methyl benzo (1,2,3)-thiadiazole-7-carbothiate) and DCINA (2,6-dichloro isonicotinic acid) activate resistance in barley against powdery mildew (Blumeria graminis f.sp. hordei). Nine BTH induced genes (Bci, barley chemically induced) have been identified in barley (BESSER et al. 2000) which are not responsive to pathogens in contrast to PR-proteins. From two Bci-genes (Bci3: similar to vsp, Bci4: Ca²⁺-binding EF-hand protein), the promoters were isolated. In transient transformation assays using promoter::GFP and promoter::GUS-constructs the functionality...

Cross-protection mechanisms between biotic and abiotic stresses in plants

D. Demaria, D. Valentino, A. Matta, F. Cardinale

Plant Protect. Sci., 2002, 38(11):490-493 | DOI: 10.17221/10532-PPS  

In order to investigate cross-protection mechanisms between stresses of different origins, greenhouse experiments were conducted to determine whether resistance levels to the fungal pathogen P. capsici were affected on wounded plants. To this purpose, tomato roots were wounded at 24h-intervals and allowed to age for up to 7 days before inoculation. Data from preliminary experiments indicate first (0-48 h old wounds) an increase in disease severity in wounded as compared to unwounded tomato plants infected with P. capsici. Then, as the wounds age, disease severity decreases to the point that plants wounded 3 days before inoculation...

Chitosan in the control of rose powdery mildew and downy mildew

T. Wojdyła

Plant Protect. Sci., 2002, 38(11):494-496 | DOI: 10.17221/10533-PPS  

Microcrystalline chitosan at concentrations from 0.025% to 0.2% was evaluated in the control of Sphaerotheca pannosa var. rosae and Peronospora sparsa. Shrubs were sprayed with chitosan 4 times at weekly intervals. Depending on the concentration used, chitosan reduced development of powdery mildew from 43.5% to 77% and its effectiveness was similar to triforine at concentration 0.03% (standard). Observations of rose leaves under light microscopic, which had been done 24 h after spraying showed, that chitosan caused strong hyphae deformation which almost completely collapse. Cell walls of the pathogen were sunken, corrugated and longitudinally...

Stimulant effect of plant activator BION on photosynthesis and its inhibitory effect on pathogenic fungi

M.K. Solntsev, V.A. Karavaev, T.P. Yurina, E.V. Yurina, A.M. Kuznetsov, I.B. Polyakova, V.V. Frantsev

Plant Protect. Sci., 2002, 38(11):497-501 | DOI: 10.17221/10534-PPS  

Spraying of wheat seedlings with aqueous preparations of CGA 245704 (BION) caused a slight decrease in chlorophyll content accompanied by the stable increase in the rate of O₂ evolution per chlorophyll. Stimulant effect of BION on photosynthetic activity depended on both the ai concentration and number of treatments. Biophysical methods based on the registration of slow fluorescence induction and thermoluminescence of wheat leaves revealed the stimulation of photosystem II activity and the increase in the rate of electron transport between the photosystems in treated plants. It is also shown that BION itself can show a partial fungitoxic...

Host gene expression at an early stage of virus resistance induction

E. GAMMELGÅRD, M.L. Mohan, R.A. Andersson, J.P.T. Valkonen

Plant Protect. Sci., 2002, 38(11):502-503 | DOI: 10.17221/10535-PPS  

Suppression subtractive hybridization (SSH) was carried out to detect genes differentially expressed in plants expressing resistance to systemic infection with Potato virus A (PVA), genus Potyvirus. Differential screening has up to now revealed 19 putative differentially expressed genes. Nothern blot hybridization has confirmed the differential expression of seven genes. Three of them were only induced by the virus, but four genes were also wound-induced.

Temporal expression of a PGIP-gene in strawberry cultivars induced by wounding or by Botrytis cinerea infection

L. Mehli

Plant Protect. Sci., 2002, 38(11):504-506 | DOI: 10.17221/10536-PPS  

The expression of a PGIP gene (polygalacturonase inhibitor protein) was monitored with semi-quantitative (SQ)-RT-PCR in green, white and red berries of the strawberry cultivar Korona upon infection with Botrytis cinerea and wounding. In addition, the PGIP expression in infected white berries was quantified in four additional cultivars. The constitutive expression of PGIP increased from green to red berries in Korona suggesting developmental regulation of the gene. Wounding and fungal infection caused a moderate or a high induction in the PGIP level, respectively. The maximum peak was observed 24 h after the treatments. In the comparative experiment...

Role of plant cell in host-pathogen interactions: Lactuca spp.-Bremia lactucae

M. Sedlářová, A. Lebeda, P. Binarová, L. Luhová

Plant Protect. Sci., 2002, 38(11):507-509 | DOI: 10.17221/10539-PPS  

Reactions of Lactuca spp. genotypes with different mechanisms of compatibility/incompatibility to B. lactucae race NL16 were examined. Microscopical study revealed significance of initial stages of infection for establishment of the host-pathogen relation. Incompatibility to the pathogen race is mostly expressed as hypersensitive reaction (HR). Rearrangement of cytoskeleton can participate in blocking of fungus penetration in resistant genotypes as well as support development of fungal infection structures in susceptible ones. During infection process peroxidase is activated, H₂O₂ released and phenolic compounds...

Several downy mildew resistance genes in Arabidopsis require signaling via a homologue of yeast SGT1

M. Tör, P. Gordon, A. Cuzick, A. Yemm, E.B. Holub

Plant Protect. Sci., 2002, 38(11):510-512 | DOI: 10.17221/10540-PPS  

A fast neutron mutant in Arabidopsis (Columbia) was identified that exhibits enhanced downy mildew (edm1) susceptibility to several Peronospora parasitica isolates, including the RPP7-diagnostic isolate Hiks1. The mutation was mapped to chr.4 and physically characterised as a 35kb deletion spanning seven genes. One of these genes restored wild-type resistance to all of the P. parasitica isolates. This gene (AtSGT1b) encodes a predicted protein that is orthologous to yeast SGT1, originally described as a key regulatory protein in centromere function and ubiquitin-mediated proteolysis. AtSGT1b contains three tatratrico-peptide...

Increase of plum resistance to natural infections with Plum pox virus

N. Minoiu, I. Oprean, I. Platon, P. Stegerean

Plant Protect. Sci., 2002, 38(11):513-515 | DOI: 10.17221/10541-PPS  

The mechanical inoculation of the plum leaves of the trees in the nursery, in the first year of growth, has stimulated the activation of the plants' defensive system, fact that lead to their resistance to natural Plum pox virus (PPV) infections. The inoculum was prepared in buffer solution phosphate + Dieca of De Bistrita plum leaves infested by the PPV. Gas chromatography coupled with mass spectrometry (GC/MS) has shown significant differences in the quantity and quality composition of the volatile compounds in the treated and untreated plants, as well as in the infected trees.

Ergosterol induces mobilization of internal calcium in tobacco cells

T. Kašparovský, M.-L. Milat, J.-P. Blein, L. Havel, V. Mikeš

Plant Protect. Sci., 2002, 38(11):516-518 | DOI: 10.17221/10542-PPS  

As for natural sterols, only ergosterol is recognized very specifically and sensitively (nM) by plants cells. Ergosterol interacts with tobacco suspension cells and trigger pH changes of extracellular medium, oxidative burst and synthesis of phytoalexins. Compared with the responses induced by cryptogein, a proteinaceous elicitor from Phytophthora sp., oxidative burst, DpH and phytoalexin accumulation were weaker with ergosterol. Cryptogein stimulated an apparent continuous uptake of external calcium within 40 min, whereas no net uptake of external calcium occurred upon the addition of ergosterol. However, the elicitation with either cryptogein...

Resistance of Arabidopsis thaliana to the obligate biotrophic parasite Plasmodiophora brassicae

A. Arbeiter, M. Fähling, H. Graf, M.D. Sacristán, J. Siemens

Plant Protect. Sci., 2002, 38(11):519-522 | DOI: 10.17221/10543-PPS  

Two resistance phenotypes to P. brassicae have been found in A. thaliana. A first resistance phenotype has been detected to the isolate 'e₂' and is polygenically inherited. The second resistance to isolate 'e₃' is caused by the dominant resistance gene RPB1. By crossing no influence could be shown for salicylic acid, jasmonic acid and ethylene in the latter resistance reaction. The RPB1 locus was narrowed down to 71 kb on chromosome 1, where three pseudogenes and 13 coding sequences are located. Six of them showed cosegregation with RPB1. None of these sequences have similarities to...

The role of type III secretion system in Erwinia carotovora subsp. atroseptica virulence

A.V. Ageichik, A.N. Evtushenkov, Y.A. Nikolaichik

Plant Protect. Sci., 2002, 38(11):523-527 | DOI: 10.17221/10544-PPS  

A hrpJ mutant of Erwinia carotovora subsp. atroseptica (Eca) was constructed and the effects of this mutation on induction of the hypersensitivity response and virulence of Eca were studied. The hrpJ mutant does not induce the HR in non-host plant Vicia faba (V. faba) and demonstrates cultivar-dependent increase or decrease of virulence on potato plants.

Monitoring of endophytic Brenneria salicis in willow and its relation to watermark disease

M. Maes, S. Baeyen, H. De Croo, K. De Smet, M. Steenackers

Plant Protect. Sci., 2002, 38(11):528-530 | DOI: 10.17221/10545-PPS  

B. salicis was monitored in willow stands, sampling trees with and without watermark disease. The study focused on Salix alba and S. fragilis. B. salicis - presence was shown not to be restricted to diseased trees. With a B. salicis-specific PCR, B. salicis was frequently detected in the wood of healthy willows. This phenomenon was further studied with PCR-DGGE of endophytic bacterial populations in healthy and diseased willow. B. salicis concentrations were fluctuating during the year, synchronized with tree activity. Water stagnation in the wood as in winter was associated with a high B. salicis...

Virulence complexity and its increasing in the Czech population of Blumeria graminis f.sp. hordei

A. Dreiseitl

Plant Protect. Sci., 2002, 38(11):531-532 | DOI: 10.17221/10546-PPS  

The virulence frequency to 12 resistance genes present in the studied cultivars in the time before their first using in grown cultivars were estimated mainly based on the data of cultivar resistance in the field. The estimated virulence frequency is compared with results obtained from investigations of the air pathogen population in 2001. The comparison shows that virulence complexity increased from about 0.90 in 1971 to 8.73 in 2001. The increase in virulence complexity was caused by necessity of the pathogen to survive on cultivars possessing respective resistance genes, it means by direct selection [(Va1, Va6, Va7, Va9, Va13, Vat, Vk1, VLa,...

Greenhouse test for the resistance to root and stem rot of Hypericum perforatum L. accessions

A. Kačergius, D. RADAITIENÉ

Plant Protect. Sci., 2002, 38(11):533-535 | DOI: 10.17221/10547-PPS  

Root and stem rot caused by soil-borne agent Fusarium avenaceum is a major disease of wild Hypericum perforatum accessions in the field collection of Medicinal and Aromatic Plants (MAP) of the Institute of Botany in Lithuania. These wild accessions of H. perforatum are growing as an initial material for breeding. In 1998-2001 the monitoring of epidemiological situation of field collection of H. perforatum showed differences among accessions considering the resistance to root rot. High intensity of root rot was observed in the third-fourth years of cultivation. The most damaged plants (> 50%) were among the accessions 219, 379,...

Occurrence of pathotypes of Diplocarpon rosae on roses in Belgium

L. Leus, G. Kegelaers, E. Van Bockstaele, M. Höfte

Plant Protect. Sci., 2002, 38(11):536-538 | DOI: 10.17221/10548-PPS  

Monospore cultures of black spot (Diplocarpon rosae Wolf) were established from isolates collected on outdoor grown roses at different locations in Belgium. These monospore cultures were tested on rose cultivars and species with different levels of natural resistance to examine the possible existence of different pathotypes. For this purpose a screening protocol including scoring after artificial infection was developed on in vitro plantlets. Differences between the examined isolates proved that there exist different pathotypes of Diplocarpon rosae in Belgium.

Statice downy mildew and plant susceptibility to Peronospora statices

C. Skrzypczak

Plant Protect. Sci., 2002, 38(11):539-541 | DOI: 10.17221/10549-PPS  

Downy mildew symptoms were observed on all aboveground statice parts. Peronospora statices develops on plants during whole vegetation period and even in wintertime, when the temperature rises above 5°C. Even on partially protected plantations most plants die in the second-year of growth. Among statice plants three groups related to plants and leaves shape can be distinguished: very susceptible, moderately susceptible and tolerant. No resistant plants were found.

Maize resistance to Sugarcane mosaic virus

R. Pokorný, M. Porubová

Plant Protect. Sci., 2002, 38(11):542-544 | DOI: 10.17221/10550-PPS  

Under greenhouse conditions 12 maize hybrids derived from crosses of four resistant lines with several lines of different level of susceptibility were evaluated for resistance to Czech isolate of Sugarcane mosaic virus (SCMV). These hybrids were not fully resistant to isolate of SCMV, but the symptoms on their newly growing leaves usually developed 1 to 3 weeks later in comparison with particular susceptible line, the course of infection was significantly slower and rate of infection lower. As for mechanisms of resistance, the presence of SCMV was detected by ELISA in inoculated leaves both of resistant and susceptible lines, but virus was...

Ways of increasing resistance to viruses into the single plant and in populations

I.T. Balashova-Lakhmatova, N.N. Balashova, V.F. Pivovarov

Plant Protect. Sci., 2002, 38(11):545-551 | DOI: 10.17221/10551-PPS  

Viruses as phytopathogenes have been discovered at 1892, and 638 plant's viruses have been identified at 1989. Some of its may be epidemic and to cause significant yield losses of cultivated crops. Increasing resistance of the single plant and populations is the necessary condition for the control of viruses spread and damage. Our proposals for the increasing resistance to viruses: For the single plant the soft correction of plant's metabolism with pretreatment of the natural bioantioxidants and immunizators - steroid glycosides. It results in lowering of virus infectivity, degree of plant's affection and increasing of the yield on 11-41% in fact (in...

Effect of rootstock clones on fire blight susceptibility in scion apple cultivars

J. Korba, K. Patáková, V. Kůdela

Plant Protect. Sci., 2002, 38(11):552-554 | DOI: 10.17221/10552-PPS  

This study was performed on 24 clonal rootstocks and 4 scion apple cultivars to evaluate rootstock/cultivar combinations for susceptibility to fire blight (Erwinia amylovora). For this aim, the clonal rootstocks were planted in plastic greenhouse in 1992 and grafted with 4 cultivars (Golden Delicious, Dulcit, Domino and Dione) in 1998. A total of 96 rootstock/cultivar combinations were tested during 1998-2001. Each year, 10 to 30 actively growing shoots per one combination were inoculated with the pathogen. The shoots were inoculated by cutting through first unfolding leaves with scissors dipped into inoculum (109 cfu/ml). The trees were misted...

Assessment of genetic resistance to crown gall in roots of apricot hybrid descents

J. Tsiantos, P. Psallidas, J.M.S. Martins

Plant Protect. Sci., 2002, 38(11):555-557 | DOI: 10.17221/10553-PPS  

Plants from five inter-varietal crosses of the apricot cultivars Bergeron, Stark Early Orange and Stella were tested for their resistance to Crown Gall in field conditions at Velestino, Greece. One-year-old plants were inoculated by immersing the roots in a suspension of a mixture of local strains of Agrobacterium tumefaciens immediately before they were planted. Resistance was evaluated by the weight of the galls eight months after inoculation. Segregation of characters was observed in all the descents, demonstrating the heterozygotic nature of the parent cultivars. The distributions of gall weights obtained in the five hybrid families indicate...

Genetic diversity of barley landraces from Near East, North Africa and Southern Europe in relation to resistance to powdery mildew

J.H. Czembor, H.J. Czembor, M. Mackey

Plant Protect. Sci., 2002, 38(11):558-560 | DOI: 10.17221/10554-PPS  

This study was conducted to determine the resistance to powdery mildew in 218 barley landraces collected in Near East (Israel, Lebanon, Syria, Turkey, Iran, Iraq), North Africa (Egypt, Algeria, Morocco) and Southern Europe (Greece, Bulgaria, Yugoslavia, Italy, Spain). Plants with resistant reactions were found in 31 (14%) landraces from which 41 single plant lines were selected. These lines were tested with 20 differential isolates of powdery mildew. Eight (19.5%) lines originated from 7 landraces (5 from Israel, 1 from Syria and 1 from Greece) were resistant to all powdery mildew virulence genes prevalent in Europe. The value of new identified sources...

Reaction of pea selections to Fusarium oxysporum f.sp. pisi (races 1, 2, 5, 6) and Fusarium solani

J. Hýsek, J. Kreuzman, J. Brožová

Plant Protect. Sci., 2002, 38(11):561-564 | DOI: 10.17221/10555-PPS  

Forma specialis (f.sp.) pisi of Fusarium oxysporum infestates pea but on other crop does not cause. Physiological races of this fungus (races 1, 2, 3 and 6) are tested on differentiation selections of pea. In the mixture with Fusarium solani there was better differentiated the reaction of single races. Own method is based on the artificial infection of the pea with the mixture of conidia and mycelial fragments of the race of Fusarium oxysporum f.sp. pisi and Fusarium solani. The roots of germinating pea are partially shortened on the top and poured with the suspension of fungi. After the germinating...

New Polish cultivars of flax resistant to Fusarium wilt

A. Andruszewska, K. Langner, M. Byczyńska

Plant Protect. Sci., 2002, 38(11):565-568 | DOI: 10.17221/10556-PPS  

The breeders consider the lack of resistance of fibrous flax cultivars to Fusarium wilt the main problem in flax cultivation in Poland. The resistance to diseases, lodging, the quality of fiber and adaptation to local climatic conditions are the main factors that have to be taken into consideration when high yields are involved. Therefore, the selected cultivars must be characterized by these features. In breeding process, conducted at the Institute of Natural Fibres in Poznań, the breeding lines of flax were tested in F4, F5, F8 and F10 in different years. The tests were conducted in provocative conditions. The main aim of breeding of flax...

Reaction of maize hybrids to ear rot caused by Fusarium graminearum Schwabe

M. Pastirčák, M. Lemmens, A. Šrobárová

Plant Protect. Sci., 2002, 38(11):569-571 | DOI: 10.17221/10557-PPS  

Ear rot caused by Fusarium graminearum Schwabe (teleomorph stage: Gibberella zeae (Schwein.) Petch) is a destructive disease of maize. In our experiment we tested twenty maize hybrids. Two inoculation techniques differing in the way of application of a macro-conidial suspension, were evaluated for their effectiveness in assessing maize resistance to ear rot. Based on the results of one season, highly significant differences in sensitivity to Fusarium ear rot between genotypes for all variants under mist irrigation and without mist irrigation, were detected.

Sensitivity of winter rapeseed (Brassica napus L.) to isolates of the fungus Leptosphaeria maculans (Desm.) Ces. et de Not

E. Plachká, L. Odstrčilová

Plant Protect. Sci., 2002, 38(11):572-574 | DOI: 10.17221/10558-PPS  

The pure cultures of the fungus Leptosphaeria maculans were isolated from the rapeseed leaves collected in Moravia. Two isolates were collected on the basis of their ability to produce yellow colour. The isolate producing yellow colour was classified as aggressive, while the isolate without the ability to produce yellow colour was not aggressive. The sensitivity to these isolates was verified in 11 rapeseed genotypes. This test was based on the method from the document Crucifer Genetics Cooperative (information document from the Department of Plant Pathology, University of Wisconsin). This method is based on the inoculation of cruciferous...

Response of winter wheat cultivars to artificial infection with Pyrenophora tritici-repentis in field and greenhouse conditions

J. Šárová, V. Šíp, A. Hanzalová

Plant Protect. Sci., 2002, 38(11):575-579 | DOI: 10.17221/10559-PPS  

The response of 22 winter wheat cultivars to artificial infection with Pyrenophora tritici-repentis has been studied in the field conditions for three years and in the greenhouse conditions as well. The set of cultivars included the cultivars registered in the Czech Republic and Swiss cultivar Arina known for satisfactory resistance to different foliar and head blights. High level of field resistance to Pyrenophora tritici-repentis was detected in cultivars Arina, Vlasta, Rialto, Athlet, Trane, Siria, Vega, Alana, Samara. Not all cultivars showed similar reaction in field and greenhouse tests. Correlation between results of the field...

Characterisation of fusarium head blight resistance located on chromosome 4A of Triticum macha

A. Steed, E. Chandler, M. Thomsett, J. Carter, S. Faure, P. Nicholson

Plant Protect. Sci., 2002, 38(11):580-582 | DOI: 10.17221/10560-PPS  

Chromosome 4A of Triticum macha carries resistance to Fusarium head blight (FHB). Double haploid lines (DH) of T. macha 4A were used to determine the type of resistance and location of the gene(s). FHB resistance and yield trait data collected over two seasons following spray and point inoculation, indicate that the resistance is of type I and is probably conferred by a single gene. The resistance was mapped with microsatellite markers to a small area of the T. macha 4A chromosome flanked by markers gwm 610 and gwm 165. This could greatly facilitate future marker assisted selection work aimed at increasing resistance to FHB...

Evaluation of gooseberry cultivars resistance to the American gooseberry powdery mildew Sphaerotheca mors uvae Schwein and its chemical control

M. Vaverka, S. Vaverka

Plant Protect. Sci., 2002, 38(11):583-587 | DOI: 10.17221/10561-PPS  

In the course of 1993-2001 extensive field trials were carried out to evaluate the resistance (susceptibility) level of 34 gooseberry cultivars to the American gooseberry powdery mildew Sphaerotheca mors uvae Schwein. Cultivars originated from the Czech Republic and from other European countries. Each tested cultivar had 7 trees (5-10 years old). Beside the resistance (susceptibility) evaluation, biological efficacy of 9 fungicides using EPPO methods has been checked at the same number of cultivars and at the same number of gooseberry trees. Highly significant differences of resistance or susceptibility were observed among gooseberry varieties....

Mapping of resistance genes to brown rust in 1R chromosome of rye (Secale cereale L.)

O.A. Baranova, A.P. Dmitriev, A.V. Voylocov, O.V. Solodukhina

Plant Protect. Sci., 2002, 38(11):588-589 | DOI: 10.17221/10562-PPS  

Five resistance genes to single-pustule isolates Nos. 12, 81,108 and 7 of brown rust were mapped on 1R chromosome of rye using two different F₂ populations. Under segregation analysis it was found linkage between genes controlling resistance to single-pustule isolates No. 12, 81, 108 and 25 and isozyme locus Prx7, which to be localized on chromosome 1R. The recombination frequencies are 0.32, 0.28, 0.29 and 0.32 correspondingly. Also we were found linkage between Prx7 and gene, controlling resistance to single-pustule isolate No. 7. Recombination frequency in this case was equal 0.10 and 0.29 in dependence on analyzing hybrids.

Occurrence and intensity of more important fungal diseases on soybean (Glycine max (L.) Merrill) cultivars

T. Duvnjak, M. Vrataric, A. Sudaric, J. Cosic

Plant Protect. Sci., 2002, 38(11):590-592 | DOI: 10.17221/10563-PPS  

The main objective of this study was to determinate the occurrence and intensity of attack by the more important fungal diseases on soybean in Eastern Croatia. Four-year investigation (1998-2001) was undertaken on 10 domestic soybean cultivars with different level of disease resistance. The investigation was set in two planting date (optimal and delayed) on experimental fields of the Agricultural Institute Osijek. Following more important diseases were established: Downy mildew, Pod and stem blight and Stem canker. Significant differences in disease incidence were caused by genetic diversity of tested materials as well as different climatic conditions...

Efficiency of leaf rust resistance genes in Martonvásár

M. Gál, L. Szunics, G. Vida, Lu. Szunics, O. Veisz, Z. Bedő

Plant Protect. Sci., 2002, 38(11):593-595 | DOI: 10.17221/10564-PPS  

The efficiency of leaf rust resistance genes in adult plants was studied on near-isogenic lines of Thatcher carrying known leaf rust resistance genes in the artificially inoculated leaf rust nursery of the Agricultural Research Institute of the Hungarian Academy of Sciences in Martonvásár over a five-year period (1997-2001). Eight of the wheat lines tested (Lr9, Lr19, Lr23, Lr24, Lr25, Lr29, Lr35, Lr37) exhibited little or no infection. Lines carrying genes Lr13, Lr44 and LrB were resistant in two years and those carrying Lr34, Lr38 and LrW in three years, after which they suffered moderate or heavy infection....

Genetic control and combining ability of resistance to American mildew, Septoria leaf spot and gall mite in black currant

T. Šikšnianas

Plant Protect. Sci., 2002, 38(11):596-599 | DOI: 10.17221/10565-PPS  

The character of gene interaction determining resistance to fungal diseases and gall mite was investigated by topcrossing method in black currant cultivars and forms of different genetic nature. For crossings three maternal varieties (testers) and seven paternal varieties and forms of different resistance to American mildew, Septoria leaf spot and gall mite were employed. Eleven cultivars and forms were assessed that differed in combining ability of resistance to fungal diseases and gall mite. Resistance to American mildew (Sphaerotheca mors-uvae) and Septoria leaf spot (Mycosphaerella ribis) is determined by genes with additive effects....

Using scab resistant donors in apple breeding

B. Gelvonauskis, D. GELVONAUSKIENÉ

Plant Protect. Sci., 2002, 38(11):600-603 | DOI: 10.17221/10566-PPS  

Apple cultivars were crossed according to the half-diallel and topcross mating design. Apple scab resistance of seedlings was estimated by using a 0-5 scale: 0 - no infection on leaves, 5 - more than 75% of leaf area infected. Percentage of scab resistant seedlings in crosses involving cultivars Prima varied from 35.8% to 67.6%, involving cultivars Florina and Arbat - 51.9-59.5% and 53.5-72.5%, respectively. Significant differences for resistance to scab were found among the crosses. Both general combining ability (GCA) and specific combining ability (SCA) were highly significant. The significance of GCA for scab resistance shows that genetic variability...

Sunflower breeding for resistance to the new races of broomrape (Orobanche cumana Wallr.) in Romania

M. Păcureanu Joiţa, E. Procopovici, S. Raranciuc

Plant Protect. Sci., 2002, 38(11):604-607 | DOI: 10.17221/10567-PPS  

The actual spectrum of the broomrape races in Romania has changed. The study of the sunflower differential set for the broomrape races, under natural and artificial infestation demonstrated the existence of a new spectrum of these races. We assigned the new race with F and the corresponding gene for resistance, with Or6 gene. In our breeding work for resistance to this new race of the parasite, the results we have this far achieved in introducing genes for resistance to broomrape into sunflower value inbred lines are important. Our use of convergent crosses based on transgressive recombination has proven very suitable as a method for incorporating...

Nicotiana benthamiana plants transgenic for PPV-SWC coat protein are resistant to PPV infection

S. Comes, A. Fanigliulo, P. Piazzolla, A. Crescenzi

Plant Protect. Sci., 2002, 38(11):608-612 | DOI: 10.17221/10568-PPS  

Two constructs containing the coat protein gene (CP) of PPV-SwC - in (+) and (-) sense - were obtained and used to transform Nicotiana benthamiana plants via Agrobacterium tumefaciens. Transformed lines were analysed for the integration of the CP gene by PCR and Southern blot. Sixty transgenic lines were selected. Expression of CP gene was investigated by immuno-western blot using a monoclonal antibody specific for PPV-SwC. Various levels of CP expression were detected in transgenic plants. R1 lines were challenged with the homologous virus and with isolates belonging to D, M and EA PPV groups. A variable...

Genetic control of Pyrenophora teres virulence to three barley accessions

N. Mironenko, O. Filatova, O. Afanasenko

Plant Protect. Sci., 2002, 38(11):612-614 | DOI: 10.17221/10569-PPS  

Ascospore progeny of cross of Pyrenophora teres f. teres isolates was evaluated on virulence to three barley genotypes. Monogenic inheritance of virulence (26 a:17 v and 31 a:18 v) was shown to cultivar Harbin and accession c 21272 and supported by results of two fungal backcrosses. The existence of three unlinked avirulence genes to CI 4922 is suggested (37 a:7 v). The model of interaction between barley resistance genes and avirulence genes with postulated fungal genotypes is proposed.

Characterisation of a PR-1: Luciferase transgenic line deployed to uncover novel defence-related Arabidopsis mutants by luciferase imaging

A. Chini, S. Murray, J. Grant, C. Thomson, G. Loake

Plant Protect. Sci., 2002, 38(11):615-616 | DOI: 10.17221/10570-PPS  

In order to identify components of the defence signalling network that may contribute to the establishment of disease resistance, we generated a novel PR-1::Luciferase transgenic line which was deployed in an imaging based screen to uncover novel defence-related mutants. Approximately, 5000 ethylmethane sulfonate (EMS) lines and 30 000 activation tagged lines were generated and screened for enhanced LUC activity via ultra low light imaging.

Protective activity of the fungal polysaccharides against fusariosis

A. Šrobárová, G. Kogan, L. Tamas, E. Machová

Plant Protect. Sci., 2002, 38(11):617-619 | DOI: 10.17221/10571-PPS  

Most of the experiments carried out in the area of plant protection have used chitin and chitosan obtained from the crustacean chitin which production is rather expensive. In our study we have applied the chitin-glucan complex prepared from the waste mycelia of filamentous fungi, from baker's yeast. Five different polysaccharides have been used for the preparation of water-soluble compounds and the assay of their antifungal activity against plant pathogen Fusarium oxysporum. In the field experiments, application of the polysaccharides led to the diminished infestation as well as to significantly increased productivity of fresh weight of the...

Effects of temperature on in vitro response of Trichoderma strains against strawberry pathogen Rhizoctonia solani Kühn.

M. Porras, C. Barrau, B. Santos, F.T. Arroyo, C. Blanco, F. Romero

Plant Protect. Sci., 2002, 38(11):620-622 | DOI: 10.17221/10572-PPS  

Effect of temperature on growth and antagonistic ability of Trichoderma spp. isolated from local strawberry culture and commercial product, against Rhizoctonia solani, strawberry pathogen, was studied in vitro. Trials were carried out twice, at 10, 25 and 30°C. Inhibitor effect was evaluated by radial growth measures of established duals on PDA's dishes, using Royse and Ries formula, to evaluate the percentage inhibition of radial growth. Design of dishes was a randomized complete block, considering 10 replicates. Data were analyzed statistically by two-way analysis of variance. The objective has been to determine the most...

Effect of aqueous extracts of aspen, black currant, folded blackberry and walnut leaves on development of pathogenic fungi

E. Stompor-Chrzan

Plant Protect. Sci., 2002, 38(11):623-625 | DOI: 10.17221/10573-PPS  

The antifungal activity of water extracts of dried leaves of folded blackberry (Rubus plicatus W. et N.), walnut (Juglans regia L.), black currant (Ribes nigrum L.), and aspen (Populus tremula L.) was assessed in the in vitro experiment. The tested fungi were Alternaria alternata, Botrytis cinerea, Rhizoctonia solani, Fusarium culmorum, F. oxysporum and F. solani. It was found that all tested extracts inhibited the development of A. alternaria and F. oxysporum, whereas the strongest inhibiting effect was exhibited by extracts of aspen (A. alternata and F. oxysporum),...

Effectiveness of CaCl₂ and Tween 80 in enhancing yeast biocontrol activity against Penicillium digitatum on tarocco orange

L. Strano, A. Campisano, V. Coco, V. Grimaldi, A. Catara

Plant Protect. Sci., 2002, 38(11):626-628 | DOI: 10.17221/10574-PPS  

Postharvest biocontrol activity of CaC_l2 and four yeasts against Penicillium digitatum was tested on Tarocco oranges. All tested organisms (Pichia anomala J121, Pichia guilliermondii NRRL Y18314, Debaryomyces hansenii DBVPG 4025 and Saccharomyces cerevisiae P1.6) significantly reduced mould incidence and severity. Application of CaCl₂ enhanced biocontrol efficacy of P. guilliermondii and S. cerevisiae, while it did not significantly affect biocontrol of P. anomala and D. hansenii.

Fungicidal preparations from Inula viscosa

Y. Cohen, A. Baider, B. Ben-Daniel, Y. Ben-Daniel

Plant Protect. Sci., 2002, 38(11):629-630 | DOI: 10.17221/10575-PPS  

Inula viscosa is a perennial plant native to the Mediterranean Basin. Extracts made from the shoots of this plant exhibited a strong fungicidal activity in vitro and in vivo. TLC analyses revealed at least 7 fungicidal compounds. Most are lipophilic. When such extracts were sprayed on the leaf surface of crop plants they effectively controlled downy mildew in grape, cucumber and tobacco; late blight in potato and tomato; gray mold in cucumber and tomato; and, powdery mildew in cucurbits and cereals. Field experiments conducted with grape vine and potato resulted in effective control of Plasmopara viticola and Phytophthora...

Fungi isolated from soil with quicksets of Chamaecyparis lawsoniana and their influence on the growth of Phytophthora cinnamomi and Rhizoctonia solani

H. Kurzawińska, I. Gajda

Plant Protect. Sci., 2002, 38(11):631-633 | DOI: 10.17221/10576-PPS  

Chamaecyparis lawsoniana is often attacked by other pathogens (from genera: Phytophthora, Pythium, Fusarium, Rhizoctonia) both when the quicksets are taken root and later, when the young plants are planted. The aim of the study was to determine an effect of saprobiotic fungi isolated from soil with quicksets Chamaecyparis lawsoniana on the growth of Phytophthora cinnamomi and Rhizoctonia solani. In our experiment, method series biotic was used (MAŃKA 1974). This method allowed to determine index of impendence for plants by Phytophthora cinnamomi and Rhizoctonia solani with the...

In vitro evaluation of fungal antagonists of Phytophthora nicotianae

R. Nicoletti, F. Raimo, E. Cozzolino

Plant Protect. Sci., 2002, 38(11):634-637 | DOI: 10.17221/10577-PPS  

As tobacco black shank epidemics caused by Phytophthora nicotianae occurred in central Italy in the late 1990s, fungal antagonists of the pathogen were searched in the rhizosphere of tobacco plants. Isolates of Aspergillus sydowii, Fusarium chlamydosporum, Gliocladium roseum, Penicillium brevicompactum, P. chrysogenum, Scopulariopsis candida and Trichoderma harzianum were recovered. Antagonism of these isolates toward P. nicotianae was evaluated in vitro: even if no hyphal interactions were observed in dual cultures, aberration in mycelial growth and morphology of sporangia occurred in most cases. Unlike those of...

Assessment of orange fruit colonization by biocontrol yeasts

V. Coco, V. Grimaldi, A. Campisano, L. Strano, A. Catara

Plant Protect. Sci., 2002, 38(11):638-641 | DOI: 10.17221/10578-PPS  

A scanning electron microscope study of citrus fruits was performed to assess the colonization process of antagonistic yeasts to green mould of Tarocco oranges under artificial inoculation. Yeast suspensions of Debaryomyces hansenii DBVPG 4025, Pichia guilliermondii NRRL Y 18134, P. anomala J121 and Saccharomyces cerevisiae P1.6 with or without addition of 1% CaCl₂ + 0.1% Tween 80 were evaluated. Penicillium digitatum was sprayed one hour later. Observation of fruit surface waxes revealed marked morphological diversity. Yeast cells and conidia were mostly localized on epicuticular waxes,...

Effect of the product of radiational removal of SO₂ and NO_x from combustion gases on the population of Globodera rostochiensis nematodes (Woll., Behrens 1975)

G. Kaup, K. Janowicz, K. Paruch

Plant Protect. Sci., 2002, 38(11):642-644 | DOI: 10.17221/10579-PPS  

The studies were carried out in a greenhouse of the Agricultural University of Szczecin, during two growing seasons. The aim of this study was determine the effect of the product obtained from radiational SO₂ and NO_x removal from combustion gases on the populations of Globodera rostochiensis nematodes - one of the most common quarantine organisms. The analysis of the effect of the applied product on the population of nematodes demonstrated their varied character of response. In the combination with the product of radiational purification of combustion gases, also significantly lower population density (number of eggs...

Biological control of seedling damping-off and root rot of sugar beet plants

M.K. El-Kazzaz, M.M. Badr, H.M. El-Zahaby, M.I. Gouda

Plant Protect. Sci., 2002, 38(11):645-647 | DOI: 10.17221/10580-PPS  

Some fungal and bacterial bioagents as well as an Actinomycete isolate were screened for their antagonistic effects against S. rolfsii, R. solani, M. phaseolina, F. oxysporum and F. solani in vitro. Trichoderma hamatum, T. harzianum, T. pseudokningii, certain isolates of Bacillus subtilis and one isolate of Pseudomonas fluorescens were the most effective bioagents in suppressing the radial growth of the four pathogens, in general. Yet, they were less effective in retarding growth of Fusarium spp. as compared with the other pathogens under study. Studying biological control showed the possibility of controlling...

Potato virus S (PVS): puzzling virus for potato breeders and seed producers

P. Dědič, J. Ptáček, V. Horáčková, V. Matoušek, N. Čeřovská, M. Filigarová

Plant Protect. Sci., 2002, 38(11):648-651 | DOI: 10.17221/10581-PPS  

In the framework of PVS eradication from breeding materials of Czech potato cultivars, the systematic research was devoted to: susceptibility of cultivars, occurrence of PVS in imported and domestic materials, and to maintenance of virus-free basic grades potatoes on breeding stations. In the field-exposure trials was proved high level of susceptibility of most cultivars to PVS and by contraries, gradualy increased proportion of maintained virus-free cultivars of foreign, as well as domestic origin. Nevertheless severe infestation still persist in some of them. The contemporary situation with maintenance of virus-free basic material in CR was demonstrated.

Incidence and severity of Septoria leaf blotch in winter wheat in relation to reduced dosage of fungicides

I. GAURILČIKIENÉ

Plant Protect. Sci., 2002, 38(11):652-655 | DOI: 10.17221/10582-PPS  

The trials were carried out over the period 1999-2000 with a view to testing the efficacy of reduced doses of triazole fungicides on winter wheat cv. Zentos. Septoria diseases (Septoria spp.) occurred on winter wheat annually. Full and reduced dosages of fungicides were highly effective against Septoria leaf blotch at an early milk stage, especially on flag leaf. Later the efficacy of reduced dosages of the fungicides was lower, than that of full doses. Due to full dosage of fungicides we obtained a sufficient yield increase annually. The yield increase through the use of 3/4 reduced doses was lower. But yield increase through reduced dosage...

Verticillium wilt in tree species; elements for integrated and innovative management strategies (EU-Project QLRT-CT99-1523)

J.A. Hiemstra

Plant Protect. Sci., 2002, 38(11):656-658 | DOI: 10.17221/10583-PPS  

Verticillium wilt is of increasing significance in European agriculture, especially in tree hosts such as olive and stone fruits, and in shade tree nurseries. In the period 1997-1998 eight European research groups participated in an EU-funded Concerted Action on this disease. Main results were the publication of "A Compendium on Verticillium wilts in tree species" (HIEMSTRA & HARRIS 1998) and an RTD-proposal submitted for financing to the 5th EU Framework Programme. This proposal was approved by the European Commission and the research started in March 2000. Ten research groups participate in a project that aims to provide essential elements for...

Decrease of Venturia inaequalis (Cook) Aderh. sensitivity to dodine and sterol demethylation inhibitor fungicides

B. Meszka, A. Bielenin

Plant Protect. Sci., 2002, 38(11):659-661 | DOI: 10.17221/10584-PPS  

The effectiveness of fenarimol and difeconazole, DMIs fungicides, and dodine was tested in two experimental orchards and in greenhouse in two seasons. In 2001 monitoring of resistance to dodine was conducted also in some commercial orchards located in main apple production. In both experimental orchards fenarimol gave significantly poorer control of apple scab than difenoconazole when curative treatments were applied. The same results were obtained in greenhouse tests using for inoculation the suspension of conidia of V. inaequalis from these orchards. In many monitored orchards, in each region, a high level of dodine resistant isolates in...

Healthiness of winter wheat and spring barley farmed under different systems

A. Łukanowski, A. Baturo, Cz. Sadowski

Plant Protect. Sci., 2002, 38(11):662-666 | DOI: 10.17221/10585-PPS  

In 1997-2001 health of roots, stem bases and harvested grain of winter wheat and spring barley cultivated in organic and conventional farms in Poland was investigated. More isolates of B. sorokiniana were obtained from spring barley in the organic farm and Fusarium spp. in the conventional farm. Results of winter wheat health estimation were not clear. In the end of cropping season higher mean disease index for roots was observed in organic farm, and for stem bases the relation was opposite. The main casual agents were Fusarium spp. Their higher occurrence was observed on roots, stem bases and also on grain in the organic...

Control of powdery mildew, Blumeria graminis (DC), in spring and winter wheat with decision support system based on assessments and weather data

R. SEMAŠKIENÉ, K. TAMOŠINAS, Z. Dabkevičius

Plant Protect. Sci., 2002, 38(11):667-669 | DOI: 10.17221/10586-PPS

As a result of the bilateral co-operation agreement between the Danish Institute of Agricultural Sciences and the Lithuanian Institute of Agriculture field trials were set up to validate and further develop the Danish decision support system PC-Plant Protection on cereal crops under Lithuanian conditions. The plots treated according to recommendation by the PC-Plant Protection were compared with untreated plots and with conventional treatments commonly applied in Lithuania. The use of fungicides against powdery mildew in winter and spring wheat according to the recommendations of the decision support system gave a significant control even at low doses....

The sensitivity of Botrytis cinerea Pers.: Fr. to new botryticides in the protection of vineyards

S. Topolovec-Pintarić, B. Cvjetković, T. Miličević

Plant Protect. Sci., 2002, 38(11):670-672 | DOI: 10.17221/10587-PPS  

Botrytis cinerea, the cause of grey mould, is a 1999 we conducted trials in order to analyse the efficacy of the pyrimethanil, cyprodinil and fenhexamide and to test sensitivity of B. cinerea to them in vineyard in which these ingredients had been applied intensively, but also in vineyards where they had never been used. Resistant B. cinerea strains to each ingredient were determined in both types of vineyards.

Associated-food-hazards: storage fungi and mites in poppy, mustard, lettuce and wheat

V. Stejskal, J. Hubert, A. Kubátová

Plant Protect. Sci., 2002, 38(11):673-680 | DOI: 10.17221/10588-PPS  

Storage fungi and mites frequently cause injury of crops and contamination of crop agro-products (= "sensitive food ingredients") by allergens and toxins. This may have serious practical consequences since currently the food safety is one of the most important priorities of EU-agricultural policy. However, the risk of occurrence of biotic-hazard in various agricultural product and food ingredients is not equal since they differ in their sensitivity to infestation/contamination by various fungi- and mite-hazards. Therefore, the goal of our study was to identify and review the fungi-hazards connected with occurrence of 5 key-species of mite-hazards,...

Control of ergot (Claviceps purpurea (Fr.) Tul.) ascoscarpus formation under the impact of chemical, biological seed dressing

Z. Dabkevičius, R. SEMAŠKIENÉ

Plant Protect. Sci., 2002, 38(11):681-683 | DOI: 10.17221/10589-PPS  

The present paper discuses the feasibility of ergot contaminants control in rye seeds through seed dressing. The objective of the work was to determinate the impact of chemical and biological seed dressing on sclerotia germination and ascocarps formation. Germination (%) of sclerotia treated with most of the investigated fungicidal action chemical seed dressers was significantly lower than that of untreated sclerotia. Although some chemical seed dressers did not give very good control of sclerotia germination, they delayed ascocarps emergence and significantly reduced their number above the soil surface at rye anthesis. Biocontrol agents did not have...

Practical experience with antiresistance strategies in the fungicides control of potato late blight

P. Doležal, E. Hausvater, V. Táborský

Plant Protect. Sci., 2002, 38(11):684-687 | DOI: 10.17221/10590-PPS  

Pathogens with rapid reproductive cycles, producing large number wind-spread dispersed infection propagules like sporangiospores, are more likely to pose problems of resistance than slowly reproducing pathogens, which are dispersed over only short distances. Phytophthora infestans, is highly adaptable pathogen capable of exerting high disease pressure on crop, and develop resistance to phenylamid fungicide methalaxyl in the potato crop in Europe (1981-1984). Metalaxyl was then reintroduced for use in mixtures coformulated with multisite compounds, and the proportion of resistance strains "subpopulations" rose again, and albeit to a level lower...

Dynamics of most important fungal diseases of strawberries in Croatia and suggestions for integrated control

T. Miličević, B. Cvjetković, S. Topolovec-Pintarić

Plant Protect. Sci., 2002, 38(11):689-691 | DOI: 10.17221/10591-PPS  

During trials (1998-2001) in the strawberry's plantation of the cv. Marmolade we monitored the appearance of the most important fungal diseases, their biology and possibilities of integrated control. Monitoring the biology of the determined fungi we established the way of overwintering, appearance of fruiting bodies and discharging of spores as well as beginning of primary infection and first symptoms of the following fungi: Mycosphaerella fragariae, Diplocarpon earliana, Gnomonia comari, Phomopsis obscurans on leaves and Botrytis cinerea on fruits. While checking the efficacy of fungicides, those most effecting to leaf diseases were...

Effects of sewage sludge on the parameters of the crop production and influence on some phytopathogenic soil fungi

I. Pisarek, E.B. Moliszewska

Plant Protect. Sci., 2002, 38(11):692-695 | DOI: 10.17221/10592-PPS  

Many types of organic wastes, including sewage sludge are used for supplementing the soil with the organic matter. The effects of this kind of fertilize are often compared to those of manure. We observed that there was no harmful impact on the winter wheat health if sewage sludge were added to the soil. In the laboratory tests we showed that water extract of sewage sludge as well as humic substances isolated from them were not sources of nutritive substances for tested fungi. Although some changes made in sewage sludge after freezing or autoclaving made them friendly for fungi. Pseudocercosporella isolates were more sensitive for tested substances...

Incidence of temperature-related abiotic diseases in Spanish garlic bulbs

J. Cabrera, F.J. López-Bellido, D. Recio, J.M. Alía, M. Serrano, C. Verdejo

Plant Protect. Sci., 2002, 38(11):696-699 | DOI: 10.17221/10593-PPS  

Several alterations of growth physiology and bulb formation in garlic (Allium sativum L.) crops, such as "rough" and "burst" bulbs, have been related by different authors with low temperatures during bulbs storage and crop development. These physiopathies affect both the yield and the quality of garlic crops. Incidence of such diseases in Spanish garlic (variety "purple of Las Pedroñeras") were studied during two consecutive years. Experimental design was factorial taking the bulb storage temperature (5°, 10°, 15° and 20°C) as variable factor. Growth indexes during crop development and final quantity of defective bulbs were evaluated....

Integrated control strategy of apple scab according to warning equipment

L. Raudonis

Plant Protect. Sci., 2002, 38(11):700-703 | DOI: 10.17221/10594-PPS  

In 1999-2001 in field trials two different apple scab control strategies were compared: (i) the current strategy - conventional disease management (CDM) and (ii) integrated disease management (IDM), according to scab infection periods. A new scab warning equipment METOS^R-D was used for detection of infection periods and forecast of disease intensity at three levels: light, moderate and severe. According to CDM apple-trees were sprayed 9 times a season. Scab warning equipment gave a possibility to optimize the use of fungicides against scab and to reduce the total spray applications per season in average till 6.3 in very susceptible cultivars...

Case studies for precision agriculture

J. Šilha, P. Hamouz, V. Táborský, K. Štípek, J. Šnobl, K. Voříšek, L. Růžek, L. Brodský, K. Švec

Plant Protect. Sci., 2002, 38(11):704-710 | DOI: 10.17221/10595-PPS  

The results of spatial variability of plant-available soil nutrients (P, K, Mg) and soil pH are described in this paper. Experiment was realized on the field of area 72 ha (orthic luvisol), located in the area of Český Brod. The use of coefficient of variation as a criterion of variability of soil agrochemical properties and yield on the field showed the following: the highest variability was observed in available P, the second highest variability was in available K, and the lowest variability of main non-mobile nutrients was in the available Mg. Soil pH was the lowest of all measured soil properties. Although the highest correlation coefficient between...

Durable resistance against Meloidogyne chitwoodi and M. fallax

F.C. Zoon, W. Golinowski, R. Janssen, D. Mugniéry, M.S. Phillips, M. Schlathoelter, G. Smant, L. Van Kruijssen, J.G. Van Der Beek

Plant Protect. Sci., 2002, 38(11):711-713 | DOI: 10.17221/10596-PPS  

The EU-funded Project QLRT-1999-1462 DREAM (Durable Resistance Against Meloidogyne) aims to contribute to sustainable production systems by developing a strategy for durable resistance management for two polyphagous quarantine root-knot nematodes Meloidogyne chitwoodi and M. fallax. The objective will be achieved by integrating expertise in breeding, nematology, botany and molecular biology. The project combines three areas of research: 1. Identification and incorporation of resistance in important arable crops: potato, pepper, ryegrass and fodder radish, 2. Study of variation in nematode virulence and of durability...

Molecular and genetic studies of the basis of virulence/avirulence in Meloidogyne chitwoodi

V.C. Blok, J. Wishart, D. Mugniéry, M. Bossis, P. Castagnone-Sereno, C. Neveu, G. Smant, C. Zijlstra, F.C. Zoon, M.S. Phillips

Plant Protect. Sci., 2002, 38(11):714-716 | DOI: 10.17221/10597-PPS  

Within the EU project DREAM there is a programme of work investigating the molecular basis of virulence and avirulence in Meloidogyne chitwoodi and which involves partners from the Netherlands, France and Scotland. In Wageningen AFLPs are being used to examine genetic diversity between populations of M. chitwoodi. Partners in Wageningen and INRA are using M. javanica and M. incognita as model systems to isolate genes producing secreted proteins that could be implicated in the host pathogen interaction. They will search for homologous sequences in M. chitwoodi. At Rennes two-dimensional electrophoresis...

Breeding tools for durable resistance to nematodes (Meloidogyne spp.) of coffee varieties

P. Lashermes

Plant Protect. Sci., 2002, 38(11):717-720 | DOI: 10.17221/10598-PPS  

Coffee is one of the world's largest traded commodities, produced in over 60 countries. Root-knot nematodes (Meloidogyne spp.) have become a major threat in all major coffee-growing areas. So far, more than fifteen species of Meloidogyne have been reported as pathogens of coffee (Coffea arabica L.). Nematocide treatments are only effective in the short term, expensive and environmentally hazardous. Growing nematode-resistant coffee trees constitutes so far the most promising option to control the pest. During the last decade, resistance to root-knot nematode have been identified in spontaneous accessions and relative diploid species. With...

Comparison of gene expression in Solanum bulbocastanum infected with virulent and avirulent isolates of Meloidogyne chitwoodi

J. Wishart, M.S. Phillips, A. Paterson, V.C. Blok

Plant Protect. Sci., 2002, 38(11):721-722 | DOI: 10.17221/10599-PPS  

Resistance to root knot nematode M. chitwoodi has been identified in the wild tuber-bearing Solanum species, S. bulbocastanum. Three pathotypes were identified suggesting at least two different genetic factors for virulence and resistance in the pathogen and the host species, respectively. Roots of S. bulbocastanum were infested with two isolates of M. chitwoodi differing in virulence. The infection process was monitored by histological examination of roots allowing time points to be identified. cDNA libraries were constructed from infected root tissue using Suppression Subtractive Hybridisation (SSH) to enrich for transcripts...