Identification of different types of resistance to stripe rust Puccinia striiformis f. sp. tritici, in some dryland wheat genotypes of Iran

Stripe (yellow) rust, caused by Puccinia striiformis f. sp. Tritici (Pst), is a globally devastating wheat disease and a critical yield-limiting factor in Iran, often resulting in severe production losses and necessitating costly chemical interventions. The deployment of host resistance remains the most economical and sustainable management strategy. This study aimed to identify different types of resistance to stripe rust among dryland wheat genotypes to support cultivar improvement programs. A collection of ۲۳۳ dryland wheat genotypes (comprising ۱۲۰ winter bread wheat, ۶۴ spring bread wheat, and ۴۹ durum wheat) was evaluated for adult plant resistance (APR) under field conditions at the Ardabil Agricultural Research Station, Iran. Parallel seedling resistance screenings against two prevalent Pst pathotypes (۶E۶A+, Yr۲۷ and ۱۴۲E۱۵۸A+, Yr۲۷) were conducted under controlled greenhouse conditions. The results revealed a spectrum of resistance responses. Forty-six genotypes (۱۹.۷%) exhibited all-stage resistance (ASR) at the seedling level against both pathotypes, suggesting the presence of known seedling resistance genes such as Yr۳b, Yr۴, Yr۵, Yr۱۰, Yr۱۵, YrSP, YrCV, YrSD, or other unidentified genes. Fourteen genotypes were susceptible as seedlings to at least one pathotype but displayed a low relative area under the disease progress curve (rAUDPC) value (۰-۱۰) in the field, indicating effective APR. Another ۱۰ genotypes, susceptible at the seedling stage, showed moderate rAUDPC values (۱۱-۳۰), characteristic of slow-rusting (SR) resistance. The remaining ۱۶۳ genotypes were highly susceptible (high rAUDPC) in the field, regardless of their seedling response. The resistant genotypes identified in this study, particularly those with APR and SR characteristics, represent valuable genetic resources for breeding programs aimed at pyramiding multiple resistance genes to develop durable resistance and achieve long-term control of stripe rust in Iran.

کلیدواژه ها:

Dryland wheat ، Race-specific resistance ، Non-race specific resistance ، durable resistance