小麦抗病品系5R625抗叶锈病基因的分子鉴定

摘要

Wheat line 5R625 shows high resistance to all ofPuccinia triticinapathotypes at seedling and adult plant stages, but its resistance mechanism is unclear. In this study, the resistance gene(s) were postulated by artificially inoculating 15P. triticina pathotypes at the seedling stage and comparing infection types with those of 36 wheat lines with knownLr genes. The result showed that 5R625 might carryLr9,Lr19,Lr24,Lr28,Lr39,Lr47,Lr51,and Lr53. Further genetic analysis to confirm the resis-tance gene(s) was carried out using the populations of Fl, F2, and F2:3 derived from the cross between 5R625 and Zhengzhou 5389 (susceptible control). A single dominant gene was found responsible for the resistance at seedling and adult plant stages. This gene was mapped on 3DL chromosome with molecular markers using the F2:3 lines. The linkage map contained five closely linked markers, including STS marker24-16 and SCAR markerOP-J09 that have proved to be cosegregated withLr24. Therefore, the leaf rust resistance gene in 5R625is most likelyLr24.%小麦品系5R625苗期和田间均对小麦叶锈病有良好抗性，但其所携带的抗病基因还不清楚。利用36个携带已知抗叶锈病基因的对照品系和15个中国小麦叶锈菌小种对5R625携带的抗病基因进行了苗期人工接种鉴定和基因推导，结果5R625对这15个叶锈菌生理小种的侵染型与Lr9、Lr19、Lr24、Lr28、Lr39、Lr47、Lr51、Lr53相同。利用5R625和感病品种郑州5389的杂交后代F1、F2和F2：3群体对5R625的抗病性进行了遗传分析，苗期和成株期的分析结果均表明5R625对小麦叶锈菌的抗性由1个显性基因控制。进一步利用F2：3家系和分子标记方法将该基因定位在3DL染色体上。与5R625携带的抗病基因连锁的5个分子标记中， STS标记24-16和SCAR标记OP-J09此前已经被证明与已知抗叶锈病基因Lr24共分离，因此，推测5R625携带的抗病基因与Lr24可能为同一基因。