Transfer of the All-Stage Resistance Stripe Rust (Puccinia striifonnis f. sp. Tritici) Resistance Gene YrZH84 in Two Southwestern Chinese Wheat Cultivars

Wheat stripe rust is a fungal disease severely affecting wheat production. Breeding resistant cultivars is the most cost-effective and efficient way to control wheat stripe rust. YrZH84 is an all-stage resistance gene with good resistance to stripe rust. In this study, YrZH84 was introgressed from germplasm Lantian36 (LT36) into the two southwestern Chinese elite wheat cultivars Mianmai367 (MM367, carrying Yr10, Yr26), and Chuanmai104 (CM104, carrying Yr26), using marker-assisted selection. F1 seeds of the two cross-combinations were planted and self-crossed to develop the advanced generations in the field. A total of 397 introgression lines (ILs) were obtained in F6 and genotyped using molecular markers Xcfa2040, Xbarc32 (linked to YrZH84), Yr10 (linked to Yr10), We173, and Xbarc181 (linked to Yr26). The 397 ILs were also evaluated for resistance to stripe rust and agronomic traits, including plant height, number of tillers, spike length, thousand-grain weight, and spikelet number. Finally, 61 lines with appreciative agronomic traits and disease resistance were selected. Among these lines, 31 lines had stripe rust resistance gene YrZH84. These selected lines are expected to become new wheat varieties for their high resistance to stripe rust and excellent agronomic traits that will make important contributions to the control of stripe rust and wheat production.