Plant Protection Science, 2013 (vol. 49), Special Issue
Wild plant pathosystemsIntroduction
A. Lebeda, J.J. Burdon
Plant Protect. Sci., 2013, 49(10):S1-S2 | DOI: 10.17221/7074-PPS 
Secondary dormancy of seeds in relation to the Bromus tectorum-Pyrenophora semeniperda pathosystemOriginal Paper
Katie Karen HAWKINS, Phil ALLEN, Susan MEYER
Plant Protect. Sci., 2013, 49(10):S11-S14 | DOI: 10.17221/30/2013-PPS
Bromus tectorum is a highly invasive annual grass. The fungal pathogen Pyrenophora semeniperda can kill a large fraction of B. tectorum seeds. Outcomes in this pathosystem are often determined by the speed of seed germination. In this paper we extend previous efforts to describe the pathosystem by characterising secondary dormancy acquisition of B. tectorum. In the laboratory approximately 80% of seeds incubated at -1.0 MPa became dormant. In the field, seeds were placed in the seed bank in late autumn, retrieved monthly and dormancy status determined. The field study confirmed the laboratory results; ungerminated...
Exposure to low water potentials and seed dormancy favour the fungus in the Pyrenophora semeniperda-Bromus tectorum pathosystemOriginal Paper
Heather FINCH-BOEKWEG, Phil ALLEN, Susan MEYER
Plant Protect. Sci., 2013, 49(10):S15-S21 | DOI: 10.17221/31/2013-PPS
In semi-arid regions of the United States, Pyrenophora semeniperda kills seeds of the winter annual Bromus tectorum. We report on pathosystem outcomes under manipulated water potential and temperature environments commonly observed within semi-arid environments for dormant and non-dormant seeds. We propose a range of outcomes for infected seeds. During summer, seeds remain dormant and are killed across a range of water potentials. During autumn, seeds survive by rapidly germinating or are killed if radicle emergence is delayed by intermittent hydration. In winter/spring, secondarily dormant seeds can be killed by the fungus. The only...
Predictive model for soil seedbank outcomes in the Pyrenophora semeniperda-Bromus tectorum pathosystemOriginal Paper
Phil Stewart ALLEN, Susan E. MEYER, Julie BECKSTEAD
Plant Protect. Sci., 2013, 49(10):S21-S23 | DOI: 10.17221/36/2013-PPS
Pyrenophora semeniperda is abundant in soil seed banks of Bromus tectorum, where it kills a fraction of seeds throughout the year. The pathogen engages in a race with host seeds for endosperm resources; the pathogen success is negatively correlated with seed germination speed. We developed a deterministic model to predict pathosystem outcomes (seed death versus seed escape), using seed bank data from 80 sites collected over a 13-year period. The response variable (killed seeds in the spring seed bank) was regressed on multiple predictor variables (pathogen and host densities at seed dispersal, amount and timing of precipitation)....
Incidence of lettuce downy mildew (Bremia lactucae) and powdery mildew (Golovinomyces cichoracearum) in natural populations of prickly lettuce (Lactuca serriola)Original Paper
Barbora MIESLEROVÁ, Aleš LEBEDA, Irena PETRŽELOVÁ, Pavla KORBELOVÁ
Plant Protect. Sci., 2013, 49(10):S24-S32 | DOI: 10.17221/51/2013-PPS
The study was focused on the wild pathosystem Lactuca serriola-lettuce downy mildew (Bremia lactucae) and lettuce powdery mildew (Golovinomyces cichoracearum). Observations were focused mainly on recording natural infection of prickly lettuce (Lactuca serriola) by downy and powdery mildews in the East Bohemia and Moravia (the Czech Republic) in the May-September period of 2007-2011, and on the influence of environmental conditions on disease incidence. Only data for July and August were used for the detailed comparisons of occurrence of both pathogens, because intensity of disease in this...
Identification of Phytophthora alni subspecies in riparian stands in the Czech RepublicOriginal Paper
Petra ŠTĚPÁNKOVÁ, Karel ČERNÝ, Veronika STRNADOVÁ, Pavel HANÁČEK, Michal TOMŠOVSKÝ
Plant Protect. Sci., 2013, 49(10):S3-S10 | DOI: 10.17221/41/2013-PPS
In the Czech Republic, Phytophthora alni was first confirmed in 2001 and the pathogen has been quickly spreading and occupying almost the whole area of the country. The pathogen attacks Alnus glutinosa or A. incana to a lesser extent and causes considerable losses of alder trees along hundreds of kilometres of riverbanks. The aim of our work was to perform the identification of P. alni isolates at the subspecific level using PCR and to determine the frequencies and distribution of particular subspecies. The allele-specific PCR primers focused on allele diversity of orthologs of ASF-like, TRP1, RAS-Ypt,...
Natural woody plant, Mallotus japonicus, as an ecological partner to transfer different pathotypic conidia of Oidium neolycopersici to greenhouse tomatoesOriginal Paper
Teruo Nonomura, Yoshinori Matsuda, Shun Yamashita, Haruhiko Akahoshi, Yoshihiro Takikawa, Koji Kakutani, Hideyoshi Toyoda
Plant Protect. Sci., 2013, 49(10):S33-S40 | DOI: 10.17221/24/2013-PPS
In our routine surveys for the powdery mildew disease in greenhouse tomatoes, we detected a new pathogen that forms pseudochains consisting of 12 conidia. To identify the original plant that dispersed this pathogen, wild plants infected with powdery mildew were monitored. The pathogen on Japanese mallotus, Mallotus japonicus, produced a similar type of pseudochain, and conidia were infectious to tomatoes. Inversely, the conidia on the tomato leaves infected M. japonicus. Infectivity assays and internal transcribed spacer (ITS)-based phylogenetic analyses indicated that the two pathogens on the tomato and M. japonicus were...
Effect of extreme temperatures on powdery mildew development and Hsp70 induction in tomato and wild Solanum spp.Original Paper
Lucie KUBIENOVÁ, Michaela SEDLÁŘOVÁ, Andrea VÍTEČKOVÁ-WÜNSCHOVÁ, Jana PITERKOVÁ, Lenka LUHOVÁ, Barbora MIESLEROVÁ, Aleš LEBEDA, Milan NAVRÁTIL, Marek PETŘIVALSKÝ
Plant Protect. Sci., 2013, 49(10):S41-S54 | DOI: 10.17221/45/2013-PPS
Changes in Hsp70 gene expression and protein level were studied in three Solanum spp. genotypes in response to short-term high and low temperatures and to infection by powdery mildew. Development of Oidium neolycopersici was compared on plant leaves and leaf discs with regard to the influence of temperature. Heat and especially cold pre-treatment of host tissues inhibited pathogenesis and decreased chlorophyll concentration. Exposure to heat increased Hsp70 (70 kDa heat shock proteins) content in all three genotypes of Solanum spp., whereas the infection induced the accumulation of Hsp70 only in susceptible S....