小麦品种“唐麦4号”抗白粉病基因的分子标记与染色体定位

唐麦4号是对小麦白粉病(Blumeria graminis f. sp. tritici)具有良好抗性的T1BL·1RS育成品种, 遗传分析结果表明, 唐麦4号携带1个抗白粉病半显性单基因, 暂命名为PmTm4。采用唐麦4号为抗病亲本的杂交组合(唐麦4号/Clement)F2代抗、感病分离群体和F3代家系, 利用集群分离分析法(BSA)建立了与PmTm4连锁的分子标记连锁图Xcau12—Xgwm611—PmTm4—XEST92—Xbarc1073—Xbarc82—Xwmc276。根据小麦7BL连锁图的标记顺序和抗白粉病基因连锁标记在中国春缺体-四体、双端体和缺失系上的定位结果, 将PmTm4基因定位于小麦7BL染色体臂末端。以上研究结果为唐麦4号抗白粉病基因在育种中的利用、分子标记辅助选择和基因累加提供了便利。

Molecular Mapping and Chromosomal Location of the Powdery Mildew Resistance Gene in Wheat Cultivar Tangmai 4

Powdery mildew, caused by Blumeria graminis f. sp. tritici, is one of the most important diseases in wheat (Triticum aestivum L.) worldwide. Breeding for resistance is the most economical and effective method for controlling the disease. Tangmai 4 carries a pair of T1BL·1RS wheat-rye (Secale cereale L.) translocated chromosomes and is resistant to a wide spectrum of wheat powdery mildew isolates. Genetic analysis indicated that a single semidominant gene in Tangmai 4 conferred resistance to powdery mildew, temporarily designated as PmTm4. Segregating F₂ population and their F₃ progenies derived from the cross between Tangmai 4 and Clement were used for bulked segregation analysis. Four SSR, one EST-SSR, and one EST-STS polymorphic markers were linked to the powdery mildew resistance gene PmTm4 in an order of Xcau12–Xgwm611–PmTm4–XEST92– Xbarc1073–Xbarc82–Xwmc276. Gene PmTm4 was physically mapped on the distal bin of chromosome 7BL using Chinese Spring nullisomic-tetrasomic, ditelisomic, and deletion lines. The results demonstrate that PmTm4 gene may be either allele at the Pm5 locus or else a member of closely linked cluster of genes.