Sources of resistance to Fusarium head blight in VIR oat collection

Fusarium head blight (FBH) is a serious disease of cultivated oats (Avena sativa L.). The objective of this study was to screen a set of oat genotypes from the VIR Avena sativa germplasm collection for the FHB resistance. Of the 155 screened genotypes 42 % belonged to both hulled and naked cultivars, 55 % were landraces and the rest were breeding lines. Screening nurseries were planted at two locations: in the Northwestern Russia in 2007–2008 with artificial inoculation by F. sporotrichioides strains and in the Russian Far East in 2009 (natural infections). The resistance data were based on three different parameters: (a) percentage of grain showing evidence of Fusarium damage, (b) the DNA content of the trichothecene-producing Fusarium species and (c) the trichothecene mycotoxin accumulation; the sum of which permitted identification of genotypes with multicomponent resistance to FHB. The highest degrees of resistance were observed in the naked cvs. Iymay (k-11014, China) and Numbat (k-14851, Australia) and by the hulled cv. Kuromi (к-11632, Japan). The most resistant landraces were the hulled oats originating from the Asian region (k-2513, k-6963, k-7766, and k-8479). Considerable similarity was observed between the resistance reactions of oat genotypes to the Fusarium disease under different environmental conditions. The identified resistant accessions may serve as crossing partners in oat breeding efforts.