The Introgression Of The Stripe Rust Resistance Gene Yr36 Into Common Wheat

Wheat stripe rust,caused by the Puccinia striformis f.sp.tritici,is a major worldwide disease.Yr36 is high-temperature adult-plant stripe rust resistance gene.It was located on the 6BS and closely linked with the grain protein content locus Gpc-B1.At a relative high temperature(25° to 35?),Yr36 confers resistance to a broad spectrum of stripe rust races.Yr36 is absent in Chinese bread wheat varieties.In this study,our purpose is discovering and transferring Yr36 to common wheat.The main results are as follows:1.Sixty-nine tetraploid wheat accessions were screened by using Yr36-specific molecular marker Yr36E1a(size 911bp),and the target band was only detected in PI415152.It was indicated that PI415152 contained Yr36 gene.PI415152 showed high resistance to stripe rust at the adult stage in Sichuan using the mixed epidemic races inoculation.It's moderately resistant at the seedling stage,suggesting that PI415152 contained other resistance gene(s).2.The synthetic hexaploid wheat Syn-SAU-69 was obtained by spontaneously chromosomes doubling of F1 hybrids between PI415152 as female parent and Aegilops tauschii AS60.Syn-SAU-69 was moderately susceptible to stripe rust at the seedling stage,while it showed resistance at the adult stage.The lower resistant level suggested the existence of resistance inhibition in new synthetic wheat compared with its tetraploid parent PI415152.3.Syn-SAU-69 was crossed with Sichuan local varieties or lines,and then F5 lines were obtained.Eight lines contained Yr36 were obtained by marker Yr36Ela screening.These lines showed resistance to stripe rust,the best resistance level was high resistance,and the worst was middle resistance.Sequencing Gpc-B1 of 6 lines with Yr36 revealed that all of them contained functional Gpc-B1 allele,same to tetraploid parent PI415152,confirming that the two genes were closely linked.4.A new line Shumai1701 with Yr36 and good yield and stripe rust resistance was obtained by selfing of the chose inbred line.