СТРУКТУРА И АРЕАЛЫ ПОПУЛЯЦИЙ ФИТОПАТОГЕННЫХ ГРИБОВ

Установление структуры и ареалов популяций фитопатогенных грибов имеет не только научную значимость, но и важное практическое значение для селекции и распределения в агроценозах болезнеустойчивых сортов, повышения эффективности защитных мероприятий, улучшения экологической обстановки на посевах сельскохозяйственных культур. В последнее десятилетие разработан ряд новых подходов в методах анализа популяций. В частности, разработаны новые типы молекулярных маркеров, техника скоростного секвенирования, внедрены новые аналитические программы. Это позволило уточнить структуру и степень локализации ряда популяций фитопатогенных грибов. Некоторые виды фитопатогенных грибов имеют широкий ареал распределения. К ним относятся многие виды ржавчинных грибов, как, например, Puccinia triticina, P. graminis, P. striiformis и некоторые виды гемибиотрофных грибов – Cochliobolus sativus, Mycosphaerella graminicola и Phaeosphaeria nodorum. В частности, показано, что на территории России существуют по меньшей мере 3 популяции P. triticina, различающиеся по вирулентности. Известны виды с узкой локализацией, например, Pyrenophora teres и Fusarium oxysporum. Узколокальное распределение популяций возбудителей болезней требует иного подхода в использовании генов устойчивости, чем для популяций, имеющих широкий ареал.

Charakterystyka zasobów genowych pszenżyta ozimego pod względem polowej odporności na choroby grzybowe

Celem pracy była charakterystyka materiałów kolekcyjnych pszenżyta ozimego pod względem polowej odporności na choroby grzybowe liści, takie jak mączniak właściwy (Blumeria graminis), rdza brunatna (Puccinia recondita) oraz septorioza liści (Phaeosphaeria nodorum). Materiał badawczy stanowiły 682 obiekty oceniane w latach 1985–2013. Bonitacja stopnia porażenia roślin przez choroby dokonywana była w oparciu o 9-stopniową skalę wg COBORU, w której 9 oznacza brak objawów chorobowych, a 1 – najsilniejsze porażenie. W celu oceny postępu biologicznego w odniesieniu do zdrowotności roślin wyodrębniono 2 grupy obiektów: badane w latach 1985–1999 oraz w latach 2000–2013. Uzyskane wyniki wskazują na duże zróżnicowanie materiałów kolekcyjnych pszenżyta pod względem polowej odporności na choroby grzybowe liści, przy czym genotypy oceniane w latach 1985–1999 charakteryzowały się większą polową odpornością na choroby grzybowe niż genotypy analizowane w latach 2000–2013.

The sexual state of Setophoma

A sexual state of Setophoma, a coelomycete genus of Phaeosphaeriaceae, was found causing leaf spots of sugarcane (Saccharum officinarum). Pure cultures from single ascospores produced the asexual morph on rice straw and bamboo pieces on water agar. Multiple gene phylogenetic analysis using ITS, LSU and RPB2 showed that our strains belong to the family Phaeosphaeriaceae. The strains clustered with Setophoma sacchari with strong support (100% ML, 100% MP and 1.00 PP) and formed a well-supported clade with other Setophoma species. Therefore our strains are identified as S. sacchari. In this paper descriptions and photographs of the sexual and asexual morphs of S. sacchari are provided. The sexual state of S. sacchari is compared with Leptosphaeria sacchari, L. saccharicola, Phaeosphaeria nodorum and Sphaerulina sacchari which have similar morphological characters; however they differ in size and colour of ascospores and in the characters of the asexual state. Setophoma is clearly separated from other Phaeosphaeria species based on the phylogenetic analysis.

Leaf spotting reaction of spring common, durum and spelt wheat, and Kamut under organic management in western Canada

Fernandez, M. R., Fox, S. L., Hucl, P. and Singh, A. K. 2014. Leaf spotting reaction of spring common, durum and spelt wheat, and Kamut under organic management in western Canada. Can. J. Plant Sci. 94: 929–935. A 3-yr field study (2010 to 2012) was conducted in southwest Saskatchewan to determine the reaction of common, durum and spelt wheat cultivars currently registered in western Canada, and of Kamut wheat, to the leaf spot disease complex (LS) under organic management. The genotypes selected for this study are often grown by organic producers in this region. Overall, the most common LS diseases observed had been observed in previous studies under conventional management in the same area. For all 3 yr, common wheat cultivars with the highest LS scores were AC Barrie, CDC Go, Superb, and Unity, while those with the lowest scores were AC Andrew, CDC Bounty and Lillian. For durum wheat, Kyle had overall the greatest LS scores. CDC Zorba had lower LS scores than the other spelt wheat, CDC Origin, and it also had the lowest LS levels of all genotypes in this study. Kamut wheat was similar to the common and durum wheat cultivars for LS severity. The relative presence of the most common LS pathogens isolated (Pyrenophora tritici-repentis, Phaeosphaeria nodorum, Phaeosphaeria avenaria f. sp. triticea, Cochliobolus sativus, Mycosphaerella graminicola) from each of the four wheat species in each of the three years is also presented and discussed.

Health of leaves and ears of spring wheat (Triticum aestivum L.) cultivated after different forecrops

The research was conduced in the years 2000-2002. The aim of the research was to determinate the health of leaves and ears of spring wheat cultivated after spring cruciferae plants such as: spring oilseed rape (<i>Brassica napus</i> ssp. <i>oleiferus</i> Metz.), chiiiese mustard (<i>Brassica juncea</i> L.), white mustard (<i>Sinapis alba</i> L.), ole iferous radish (<i>Raphanus sativus</i> var. <i>oleiferus</i> L.), false flax (<i>Camelina sativa</i> L.), crambe (<i>Crambe abbysinica</i> Hoechst.), as well as after oat (<i>Avena sativa</i> L.) as con trol. Spring wheat cv. Torka was sown after: pIoughed stubble cultivated on this field, ploughed stubble and straw, ploughed stubble with straw and 30 kg nitrogen per hectare. During all the years of studies on leaves and ears of spring wheat septo ria of leaf blotch and glume blotch (<i>Mycosphaerella graminicola, Phaeosphaeria nodorum</i>) were found. Brown rust (<i>Puccinia recondita</i> f. sp. <i>tritici</i>) was seen on leaves of wheat only during years 2001-2002. Besides on ears fusarium ear blight (Fusarimn sp.) was present in 2002 and sooty mould (<i>Cladosporium sp., Alternaria</i> sp.) in 2001. According to health of overground parts of plants the good forecrops to spring wheat were oat, chinese mustard, oleiferous radish. The biggest impact on presence of diseases of leaves and ears had the weather during years of studies. The use of after harvest rests didn't have significant influence on health of leaves and ears of spring wheat.

Endophytic Fungi from Plums (Prunus domestica) and Their Antifungal Activity against Monilinia fructicola

Enophytic fungi were isolated from plum (Prunus domestica) leaves, identified with ITS1 and ITS4 primers, and their antagonistic activity was tested against Monilinia fructicola, which causes brown rot, blossom blight, and twig blight of stone fruits, and Colletotrichum gloeosporioides, which causes anthracnose on a variety of fruit crops. The production of antifungal compounds was determined in agar-diffusion and volatile inverted-plate tests. A total of 163 fungi were recovered from 30 plum trees, representing 22 cultivars. Twenty-nine morphotypes were detected, but only 14 species were identified genetically. The most frequently isolated species was Phaeosphaeria nodorum, constituting 86.5% of the total isolates. Four isolates produced inhibitory volatiles to M. fructicola; however, no isolate produced volatiles inhibitory to C. gloeosporioides. The volatiles produced by these fungi were identified as ethyl acetate, 3-methyl-1-butanol, acetic acid, 2-propyn-1-ol, and 2-propenenitrile. The fungal volatiles inhibited growth and reduced width of the hyphae, and caused disintegration of the hyphal content. This is the first study describing fungal endophytes in stone fruits. The P. nodorum strains producing inhibitory volatiles could play a significant role in reduction of M. fructicola expansion in plum tissues. Potential of these strains for biological control of this pathogen on stone fruits warrants further investigation.

Występowanie ważnych gospodarczo chorób pszenicy ozimej w Polsce w latach 2006–2010

Źródłem informacji, na podstawie których ocenia się stan fitosanitarny roślin uprawnych w Polsce jest monitorowanie nasilenia występowania agrofagów. Ogólnokrajowy monitoring gospodarczo ważnych agrofagów oparty jest na współpracy Instytutu Ochrony Roślin – Państwowego Instytutu Badawczego (IOR – PIB) w Poznaniu z wojewódzkimi inspektoratami Państwowej Inspekcji Ochrony Roślin i Nasiennictwa. Współpraca polega na prowadzeniu, jednolicie według metodyk opracowanych w IOR – PIB, obserwacji agrofagów, w wyniku których uzyskiwane są dane o nasileniu ich występowania na przestrzeni lat. Informacje te gromadzone są w Zakładzie Metod Prognozowania Agrofagów i Ekonomiki Ochrony Roślin IOR – PIB i na ich podstawie przedstawiany jest obraz zmian dotyczących nasilenia występowania, rejonizacji i rozprzestrzeniania się chorób i szkodników roślin uprawnych. W ostatnich pięciu latach głównymi chorobami pochodzenia grzybowego obserwowanymi w uprawach zbóż były: mączniak prawdziwy zbóż i traw – Blumeria graminis (DC.) Speer., rdza brunatna pszenicy – Puccinia recondita Rob. Ex Desm f. sp. tritici (Eriks.) Johnson, septorioza plew pszenicy – Phaeosphaeria nodorum (E. Müller) Hedjaroude (syn. Stagonospora nodorum (Berg.) Castellani et Germano, łamliwość źdźbła zbóż i traw – Oculimacula yallundae (Wollwork, Spooner) Crous, Gams, oraz zgorzel podstawy źdźbła – Gaeumannomyces graminis (Sacc.) Arx et Olvier.

Association Mapping of Quantitative Resistance to Phaeosphaeria nodorum in Spring Wheat Landraces from the USDA National Small Grains Collection

Stagonospora nodorum blotch (SNB), caused by Phaeosphaeria nodorum, is a destructive disease of wheat (Triticum aestivum) found throughout the United States. Host resistance is the only economically feasible option for managing the disease; however, few SNB-resistant wheat cultivars are known to exist. In this study, we report findings from an association mapping (AM) of resistance to P. nodorum in 567 spring wheat landraces of diverse geographic origin. The accessions were evaluated for seedling resistance to P. nodorum in a greenhouse. Phenotypic data and 625 polymorphic diversity array technology (DArT) markers have been used for linkage disequilibrium (LD) and association analyses. The results showed that seven DArT markers on five chromosomes (2D, 3B, 5B, 6A, and 7A) were significantly associated with resistance to P. nodorum. Genetic regions on 2D, 3B, and 5B correspond to previously mapped quantitative trait loci (QTL) conferring resistance to P. nodorum whereas the remaining QTL appeared to be novel. These results demonstrate that the use of AM is an effective method for identifying new genomic regions associated with resistance to P. nodorum in spring wheat landraces. Additionally, the novel resistance found in this study could be useful in wheat breeding aimed at controlling SNB.