用AFLP标记来自偏凸山羊草的抗条锈病新基因YrG775

Tagging a Novel Yellow Rust Resistance Gene YrG775 Derived from Aegilops ventricosa with AFLP Marker

目的研究小麦抗病种质贵农775对条中32条锈病菌的抗性基因的数量、来源,对于抗条锈病新基因的寻找、已知抗性基因的合理使用均有重大意义。方法对西农97148×贵农775的杂交F2后代人工接种条中32条锈病菌进行抗性鉴定,并根据抗性鉴定结果划分抗感病池用AFLP技术寻找其连锁标记。结果根据抗感病单株分离比例确定贵农775的抗病性由两对抗条锈病基因控制。从128个AFLP引物组合中筛选到与其中一个抗病基因YrG775紧密连锁的多态性标记M8P15290bp,该标记仅能在原始亲本偏凸山羊草中检测到。结论由于来源于偏凸山羊草的抗条锈病基因Yr17苗期不抗条中32条锈病菌,综合抗性鉴定和分子生物学试验结果,可以推断YrG775很可能是一个来自偏凸山羊草并与已知抗条锈病基因不同的新基因。

[Objective] The number and the origin of Yellow Rust resistance （Yr） gene in wheat germplasm Guinong775 were studied as they are important for finding new Yr gene and the rational usage of named Yr genes. [Method] The F2populations crossed by Xinong97148 × Guinong775 were inoculated with the pathogenic strains CY32 to test their resistance. The resistant and susceptible pools were established based on the authentication result, and the two pools with 128 AFLP primer combinations were screened. [Results] The Chi-square test showed that the yellow rust resistance of Guinong775 was controlled by two duplicate effect genes. In 128 AFLP primer combinations, the primer combination M8P15 had a polymorphic band about 290bp linked to the resistance gene YrG775 （temporarily designed）, one of the two duplicate genes. F2 segregations analysis had proved that this band closely linked to the gene and only Aegilops ventricosa （one of the original parents of Guinong 775） had this polymorphic band. [Conclusion] Since the Yr17, the only resistance gene was known for derived from Aegilops ventricosa, had no resistance to the pathogenic strains CY32 during the seedling period, so the gene YrG775 identified in this paper might to be a novel yellow rust resistance gene.