Genetic Resources and Crop Evolution ( IF 1.6 ) Pub Date : 2020-04-16 , DOI: 10.1007/s10722-020-00938-z Jun Cao , Zhibin Xu , Xiaoli Fan , Qiang Zhou , Guangsi Ji , Fang Wang , Bo Feng , Tao Wang
Stripe rust, which is caused by Puccinia striiformis f. sp. Tritici (Pst), is one of the most destructive wheat (Triticum aestivum L.) diseases worldwide. To control stripe rust, the best strategy is breeding and growing novel resistant cultivars. Qubaichun (QBC), a Tibetan wheat landrace, displays near-immune resistance to wheat stripe rust in western China. Previously, our studies have shown that the stripe rust resistance of QBC is controlled by a dominant gene at the seedling stage and two independent genes at the adult-plant stage. These two genes comprise an all-stage resistance (ASR) gene and a durable adult resistance gene, which was identified as Yr18. The unknown ASR gene is temporarily named Yrqbc. To map this gene, a segregating population of QBC × Chinese Spring (CS) was generated. SSR analysis, BSR-seq and Infinium 660 K iSelect SNP genotyping were successively performed. The results show that Yrqbc finely mapped to a 5.1 cM genetic interval between molecular markers A009200 and A009192, and the genetic distance to the marker A009200 was 0.1 cM. Furthermore, Yrqbc was confirmed to be Yr5 by sequencing. Diagnostic markers are used for detection Yr5 and Yr18 in 323 new cultivars (lines) worldwide. The results show that 27 cultivars (lines) carry the durable adult resistance gene Yr18, and only one material carrying the ASR resistance gene Yr5. In order to analyse the effectiveness and practicality of transferring the pyramided of Yr18 and Yr5, these two stripe rust resistance genes were introduced into elite cultivars which lost resistance. Field test results verified that the combination of Yr5 and Yr18 could provide effective resistance to stripe rust for the whole life of wheat, which provided a genetic foundation for the near immunity of elite cultivars. As a result, this Tibetan landrace could be used for developing high-level, durable resistant wheat cultivars.