Identification and expression of the gene Yr2 for resistance to Puccinia striiformis in the wheat differential cultivars Heines Kolben, Heines Peko and Heines VII

Abstract

Genetic data showed that a common gene was present in the three differential wheat cultivars Heines VII (Yr2), Heines Peko (Yr2, Yr6) and Heines Kolben (Yr6) expressed against the race 109E9 of Puccinia striiformis which possesses virulence for Yr6 and avirulence for Yr2. This supported the hypothesis that Heines Kolben carries the gene Yr2 in addition to Yr6 for resistance to yellow rust in a genetic background in which Yr2 is weakly expressed in seedlings. F1, F2 and F3 progenies from the cross Heines Kolben x Peragis confirmed the monogenic segregation of Yr2 in Heines Kolben and demonstrated the variation of its expression with environmental conditions.