分子标记选择小麦抗白粉病基因Pm4b、Pm13和Pm21聚合体

Selecting the Pyramids of Powdery Mildew Resistance Genes Pm4b, Pm13 and Pm21 in Wheat Assisted by Molecular Marker

培育多个抗病基因聚合的小麦品种是提高其抗病广谱性和持久性的有效途径之一。利用小麦抗白粉病基因Pm4、Pm13、Pm2 1的特异PCR标记 ,对含有Pm4b、Pm13、Pm2 1的小麦品系复合杂交F2 代 4 0个植株进行检测 ,从中选择到Pm4b +Pm13+Pm2 13个基因聚合的抗病植株 11个 ,检测、选择到Pm4b +Pm13、Pm4b +Pm2 1、Pm13+Pm2 12个基因聚合的抗病植株 19个 ,为持久、广谱抗病小麦育种奠定了基础。研究还表明 ,3个独立的显性抗病基因在F2 代分离群体中的分离比例基本符合孟德尔独立分配定律 ,在小麦背景下的遗传稳定性 ,与该基因供体和普通小麦的亲缘关系密切相关 ,亲缘关系越远 ,丢失的概率越大。因此 。

Pyramiding resistance genes have been suggested as one of the most effective methods for preventing breakdown of major gene conferring resistance to powdery mildew within a very short period. The PCR markers of the powdery mildew resistance gene Pm4b, Pm13 and Pm21 were used to identify the genes in F 2 plants of combination among the wheat lines containing Pm4b, Pm13 and Pm21 respectively. The results indicated that all the plants containing any one gene, two genes or three genes of Pm4b, Pm13 and Pm21 showed resistance to powdery mildew, while the plants lacking the resistance gene were susceptible to powdery mildew. The tightly linked markers of the resistance genes were powerful tools for the identification of Pm4b, Pm13 and Pm21 in breeding program. Eleven plants pyramiding three genes of Pm4b+Pm13+Pm21, 10 plants pyramiding Pm4b+Pm13, 6 plants pyramiding Pm4b+Pm21, and 3 plants pyramiding Pm13+Pm21 two genes, were selected from 40 plants of the F 2 population. They can be used as parents to breed wheat for powdery mildew resistance. The results reconfirmed that the stability of a resistance gene is closely related to the relationship between donor and receptor of the gene. The study showed that molecular marker selection has more advantage than the traditional phenotype detection especially in wheat breeding for pyramiding of resistance genes.