普通小麦-柔软滨麦草易位系M852-1抗条锈基因的遗传分析和分子作图

Genetic analysis and molecular mapping of stripe rust resistance gene in wheat Leymus mollis translocation line M852-1

M852-1是经杂交和回交培育的普通小麦-柔软滨麦草易位系,苗期对我国小麦条锈菌流行小种均表现良好抗性。为明确其抗条锈性遗传规律,本研究选用条锈菌流行小种(类型)CYR29、CYR32、CYR33和Su11-7的单孢菌系对其与铭贤169杂交F1、F2、F3及BC1代群体进行遗传分析,同时应用420对SSR引物对接种CYR32的M852-1/铭贤169 F2代144个单株作图群体进行抗病基因定位。结果表明,M852-1对供试小种均表现免疫或近免疫,对CYR29的抗锈性由1对显性基因控制,对CYR32、CYR33和Su11-7的抗锈性均由1对隐性基因控制。筛选到3个与抗CYR32基因连锁的SSR标记Xbarc124、Xbarc200和Xgwm429,遗传距离分别为6.3、5.6和9.7 cM。根据SSR标记锚定性将该基因定位于小麦2BS染色体,暂命名为YrM852。基因来源、分子标记检测及染色体位点分析表明,YrM852很可能是1个不同于目前已知抗条锈病基因的新基因。

Stripe rust, caused by Puccinia striiformis f. sp. tritici （Pst）, is one of the most devastating disea- ses of wheat throughout the world. M852-1, a translocation line derived from hybridization and cross between Triticum aestivurn and Leymus mollis, is resistant to the current prevalent Pst races in China. To identify and map the gene（s） conferring resistance to stripe rust, Pst races （ CYR29, CYR32, CYR33 and Sull-7 ） were selected to test the F~, F2, Fa and BC~ generations derived from the cross M852-l/Mingxian 169 at the seed- ling stage. The gene conferring resistance to CYR32 in M852-1 was mapped by linked SSR （simple sequence repeat） markers. The genetic analysis showed that one dominant resistance gene to CYR29 and one recessive resistance gene to CYR32, CYR33 and Sull-7 respectively were estimated for M852-1. By using SSR to ana- lyze the 144 individuals in the F2 segregating population, three markers on chromosome 2BS （Xbarc124, Xbarc200 and Xgwm429） were identified and linked with the resistance gene YrM852 （temporarily designat- ed） at the distance of 6.3, 5.6, 9. 7 cM, respectively. Furthermore, based on the source of the gene YrM852, molecular detection and chromosome location, YrM852 might be a novel stripe rust resistance gene.