Improving Stripe Rust Resistance and Agronomic Performance in Three Elite Wheat Cultivars by Using a Combination of Marker Detection and Phenotypic Selection

Abstract

\n Wheat is an important cereal crop globally and improvement programs reach a plateau from ever-evolving stripe rust pathogen. Stripe rust, caused by Puccinia striiformis f. sp. Tritici (PST), is a fungal disease that devastates global wheat production. This disease is most effectively restrained by developing and deploying cultivars with highly durable resistance. The utilization of resistant genes is essential for breeding resistant cultivars. To improve stripe rust resistance and achieve favorable agronomic performance in commercial cultivars, an adult plant resistance gene Yr48 was introgressed from PI610750 into three Chinese elite wheat cultivars Chuanmai 42, Lunxuan 987, and Bainongaikang 58 using a combination of marker detection and phenotypic selection.The three Chinese elite cultivars as the recipient parent were used to cross with the donor parent PI610750. Eighty-seven introgression lines (ILs) were gained from all three crosses in the F5 generation. To validate the introgression lines possessing Yr48, SSR markers previously reported to be linked to the resistance gene loci were used to detect its presence or absence in different genetic backgrounds. Resistance and effect of introgressed Yr48 were studied using F6 and F7 grain grown in the field. The ILs from three crosses were evaluated the agronomic traits and the stripe rust reaction following stringent phenotypic criteria. Both phenotype and genotype data confirmed the presence of Yr48. A combination of phenotypic selection and marker-assisted breeding revealed that 9 selected lines had more application prospects. Those ILs had increased TGW (4.5–31.1%) in infested environments compared to the recipient parents. New lines with improved disease resistance and better agronomic performance should have more advantages than the original cultivars in wheat breeding programs.