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Background. Powdery mildew is one of the harmful and destructive foliar diseases of cereal crops, caused by the fungus Вlumeria graminis (DC.) E.O. Speer f. sp. tritici Em. Marchal. Annual harvest losses may reach 10–15%, and up to 30% in an epidemic year. The VIR collection contains rich diversity of wheat, a valuable source of original material for wheat resistance breeding programs.The aim of this study was to generalize the results of long-term field and laboratory investigations on powdery mildew resistance in spring bread wheat of Nordic origin from the VIR collection and search for accessions resistant in all development phases.Materials and methods. Powdery mildew resistance was analyzed in 279 accessions originated from Sweden, Finland, Norway and Denmark. The tests were performed from 1961 to 2019 against a natural population of the fungus in VIR’s experimental field (Pushkin, St. Petersburg). Field and laboratory studies were carried out in accordance with the guidelines developed by VIR.Results. The analysis of the field data on powdery mildew resistance in spring bread wheat accessions against the Pushkin population of the fungus showed that many Nordic accessions were resistant from 1970 till 1990. These data were retested in 2012–2013. One hundred and five accessions of old landraces and modern cultivars of Nordic origin were studied under field and laboratory conditions for their response to a natural population of the fungus. Accessions resistant in all phases of plant development were identified.Conclusion. Swedish cultivars ‘Sunnan’ (k-58177), ‘Canon’ (k-60992), ‘Sober’ (k-61080) ‘Dragon’ (k-61515) and ‘Dacke’ (k-63479) preserved their resistance to the powdery mildew population beginning from 1993. Spring bread wheat cultivars ‘SW Vals’ (k-64436), ‘SW Milljet’ (k-64434), ‘SW Estrad’ (k-64435), ‘SW Vinjet’ (k-64436), ‘Zebra’ (k-64707), ‘SW Kungsjet’ (k-66036), ‘SW Kronjet’ (k-66097) and ‘Boett’ (k66353) demonstrated adult and seedling resistance in the period from 2005 to 2019.

Background. Recently, an increased interest in crop landraces has been observed among scientists working with plant genetic resources (PGR). Institutes have been organizing collecting missions to explore old varieties still cultivated locally. Attention paid to landraces is also associated with the introduction of GIS technologies into PGR studies. The N. I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) holds a unique collection of spring bread wheat landraces. One of the Institute’s top priorities is to develop and maintain a passport database, using a set of fields specifically fit for landraces.Analysis of the passport database. The passport database ‘Spring Bread Wheat Landraces in the VIR Collection’ is analyzed here. The database contains information on 5,925 accessions and has 36 fields. Statistical data are presented for the main fields: origin, collection site, botanical variety, year of registration in the collection, donor institute or expedition, and collector’s name.

Background. Powdery mildew of bread wheat caused by the fungus Blumeria graminis (DC.) E.O. Speer f. sp. tritici Em. Marchal is a widespread foliar disease of wheat in regions with cool and wet climate. It infects the foliage, stem and spike of the wheat host and causes yield reduction. Breeding for resistance is the economical way to control this disease. The object of this work was to analyze spring cultivars of wheat (Triticum aestivum L.) for powdery mildew resistance and some productivity indicators.Materials and methods. The study involved 150 European spring bread wheat cultivars whose resistance to the fungus was assessed at the seedling, heading and flowering phases of plant development. The population of the fungus manifested virulence to Pm1, Pm2, Pm3a-d, Pm4a-b, Pm5a, Pm6, Pm7, Pm8, Pm9, Pm16 and Pm19, and avirulence to Pm12. The damage to seedlings was evaluated using the scale from 0 (no damage) to 4 (abundant pustules). Resistance of the adult plants was analyzed according to the scale from 9 (no damage) to 1 (abundant pustules).Results and conclusions. Of the 150 cultivars, resistance at the seedling stage was shown by 12,7%, and at the adult stage by 20,1%. The cultivars ‘Dacke’, ‘SW Estrad’, ‘Sparrow’ and ‘Aranka’ were resistant in all phases of plant growth. ‘Naxos’ was characterized by a short period from seedlings to heading. The cultivars ‘Aranka’, ‘Zuzana’, ‘Septima’, ‘Tercia’ and ‘Sparrow’ had short stems, while ‘Torka’, ‘Sparrow’ and ‘Pasteur’ – large grains.

Актуальность. Одним из важнейших факторов снижения урожайности и качества зерна мягкой пшеницы Triticum aestivum L. является поражение грибными болезнями, в том числе листовой ржавчиной (возбудитель Puccinia triticina Erikss.). Вследствие микроэволюционных процессов в популяциях возбудителей болезней сорта часто теряют свою резистентность, поэтому необ