小麦黑芒性状的遗传分析与基因定位OA

In common wheat(Triticum aestivum),the black awn trait is relatively rare,and its genetic mechanism remains unclear.This study aims to genetically map the black awn trait in wheat,laying the foundation for subsequent gene cloning and breeding applications.Analysis of the F2∶9 RIL population derived from'Yang16G216'(white awn)/'Yang16M6393'(black awn)revealed a segregation ratio of white to black awns consistent with 3∶1.Further bulked segregant exome sequencing(BSE-Seq)was performed on the F2∶5 RIL population from the cross'Yang16C106'(white awn)/'Yang20M5623'(black awn).Among 86 566 single nucleotide polymorphism(SNP)sites,456 ones were highly significantly associated with the black awn trait(at the 99%confidence level).Of these,99.34%(453)were densely distributed in the distal end of chromosome 1AS(65)and the peri-centromeric region of chromosome 1BL(388),demonstrating that the trait was co-regulated by these 2 loci.Fine mapping localized the chromosome 1AS locus to the 0～8.1 Mb interval,and the chromosome 1BL locus to the 360.4～399.5 Mb interval,which was found to be closely linked with the stripe rust resistance gene Yr26.By breaking this linkage and combining multi-disease resistance gene detection,3 white-awn lines were selected from the F2∶5 RIL population,which pyramided the stripe rust resistance gene Yr26,powdery mildew resistance gene Pm21,leaf rust resistance gene LrYang16G216,and Fusarium head blight resistance gene Fhb1.This study provides both theoretical and material foundations for map-based cloning of the black awn gene,as well as for pyramiding multiple disease resistances and molecular breeding applications.