Identification of Three Novel QTLs Associated with Yellow Rust Resistance in Wheat (Triticum aestivum L.) Anong-179/Khaista-17 F2 Population

Abstract

Wheat yellow rust (YR) caused by Puccinia striiformis is lethal for the leaf photosynthetic process, which substantially affects yield components and ultimately causes drastic yield reduction. The current study aimed to identify all-stage YR resistance linked QTLs in the best cross-combination. Experimental materials were phenotyped for disease severity in YR-hot spot area at Cereal Crops Research Institute, Pirsabak Pakistan in Khyber Pakhtunkhwa province in 2019 and 2020 and 2020 and 2021 Rabi seasons. The AN179 × KS17 was found to be the best cross combination, which showed high resistance to YR, whereas crosses AN179 × PK15 and PR129 × PK15 demonstrated susceptibility to YR with high disease severity. The recombinant inbred lines (RIL) F2 wheat population Annong-179/Khaista-17 demonstrated highly desirable YR resistance and yield component traits. Simple sequence repeat (SSR) markers were used to genotype the RIL population and their parents. Three novel QTLs linked to all-stage YR resistance were found on chromosomes 2BS, 3BS and 6BS, which explained 1.24, 0.54, and 0.75 phenotypic variance, respectively. Incorporation of the newly identified novel YR-resistance associated QTLs into hybridization wheat breeding program could be effective for marker-assisted selection of the improved and sustainable resistance.

The Biological Roles of Puccinia striiformis f. sp. tritici Effectors during Infection of Wheat

“…Other Yr genes could provide effective resistance against only a few subsets of Pst races, and this resistance can be overcome once the new virulent strain emerges, so this kind of resistance is non-durable and race-specific [ 11 ]. Currently, although more than 150 temporarily or permanently designated Yr genes, together with over 300 quantitative trait loci (QTL), have been identified [ 12 , 13 , 14 ], only a few Yr genes directly linked to resistance have been isolated to date, including Yr18 [ 15 ], Yr36 [ 16 ], Yr46 [ 17 , 18 ], Yr5 / YrSP [ 19 ], Yr7 [ 19 ], Yr15 [ 20 ], Yr27 [ 21 ], Yr28 [ 22 ], and YrU1 [ 23 ] genes. Yr5 / YrSP and Yr7 genes encode the nucleotide-binding site and leucine-rich repeat (NBS-LRR) proteins with a non-canonical N-terminal zinc-finger BED domain.…”