DefinePK

Abstract

Wheat is an indispensable food crop worldwide, including in Ethiopia. The Ethiopian government is striving to achieve wheat self-sufficiency through initiatives such as expanding production areas, promoting irrigated wheat, and bridging yield gaps. However, stem rust and yellow rust remain the most serious threats to wheat production due to the emergence of virulent races of Puccinia graminis f. sp. tritici and temperature-adapted races of P. striiformis f. sp. tritici, which can cause yield losses of up to 100%. The current study aimed to evaluate 139 bread wheat accessions along with six check varieties under natural infection conditions for both stem rust and yellow rust resistance. The entries were planted in an augmented design across two yellow rust hot-spot locations and one stem rust hot-spot location to assess their slow-rusting characteristics. Slow-rusting resistance at the adult-plant stage was evaluated using final rust severity (FRS) and the average coefficient of infection (ACI). Based on combined FRS and ACI data, most of the tested accessions and all check varieties exhibited high disease severity. However, five accessions viz., 31346, 31405, 31643, 34209, and 34797 consistently showed low FRS and ACI values across locations and years, indicating promising levels of slow-rusting resistance. These accessions, exhibiting durable resistance to both stem and yellow rust, could be backcrossed with high-yielding but susceptible Ethiopian wheat varieties to reduce yield losses and enhance the genetic diversity of the national wheat germplasm.