Expression of resistance to stripe rust, powdery mildew and the wheat curl mite in Triticum aestivum × Haynaldia villosalines

Abstract

Stripe rust, powdery mildew and the wheat curl mite (Aceria tosichella) (WCM) are common problems in wheat throughout the world. The expression of resistance to these diseases and the mite was investigated in wheat ×Haynaldia villosa chromosome addition, substitution and translocation lines. Progeny tests and cytogenetic examinations were carried out on crosses of the 6VS translocation line with susceptible genotypes of wheat to study the inheritance of the stripe rust, powdery mildew and WCM resistance. These studies also were used to elucidate if the resistance was associated with the H. villosa 6V chromosome. The test results confirmed the presence of a high level of resistance to stripe rust in wheat × H. villosa 6V addition and 6VS translocation lines. However, progeny tests and genomic in situ hybridization (GISH) analysis showed that the stripe rust resistance gene, Yr26 was not associated with the H. villosa chromosome arm 6VS. While WCM and powdery mildew resistance were always associated with the presence of the 6VS chromosome arm in the F2 and F3 populations. The study also showed that most wheat × H. villosa addition or substitution lines were heterogenous in their reaction to stripe rust. The possible reasons for the heterogeneous response to stripe rust in wheat lines carrying the H. villosa chromosomes 2V, 3V and 4V are discussed. Key words: Haynaldia villosa, Puccinia striformis, Aceria tosichella, stripe rust, expression of resistance, addition lines, substitution lines, 6VS-translocation