Powdery mildew resistance genes in Latvian barley varieties

Thirty-three Latvian spring barley varieties and breeding lines and 90individual progenies from these were tested at the seedling stage for their reaction to a maximum 37 isolates of Blumeria graminis f. sp. hordei. Eighteen varieties were composed of two or three lines with different resistance. TwelveMl powdery mildew resistance genes(a1, a6, a7, a8, a9, a12, a13, at, g, k1, (Kr) and La) and four Ml genes closely linked to the Mla locus [a(Al2), a(No3), a(Em2) and a(Ru3)] were found. Mla8, Mlg and Mlk1 were the most frequent genes that occurred among the tested genotypes. The results confirm the pedigrees of all genotypes apart from cv. Agra and the breeding line L-215.