小麦品系ICA56抗条锈病鉴定及其抗性基因SSR标记

 小麦品系ICA56对条锈菌优势生理小种CYR30、CYR31和CYR32均表现免疫反应;遗传分析表明,ICA56携带一个显性抗条锈病基因。基因等位性测定显示,ICA56所含抗条锈病基因不同于已知抗锈基因Yr5、Yr10、Yr15和Yr26,暂将该基因定名为YrICA56。利用川麦28/ICA56的F₂群体及抗感亲本筛选到5对SSR引物WMC503、Xgwm261、Xgwm296、WMC112和Xgwm210与YrICA56连锁,遗传距离分别为16.6、10.4、7.0、4.5和14.1cM。根据Mapmaker3.0确定标记、YrICA56和着丝点在染色体上的顺序为:-WMC503-Xgwm261-Xgwm296-YrICA56-WMC112-Xgwm210-着丝点-。根据作图结果,将YrICA56定位在2DS。目前定位在2DS上的抗条锈病基因有Yr16和YrKat。Yr16为成株期抗性,YrKat属温敏抗性,而YrICA56在苗期和成株期对条锈病均表现免疫,由此推测YrICA56是一个新的抗条锈病基因。

Identification and SSR mapping of a stripe rust resistance gene in wheat line ICA56

A wheat line, ICA56, carried a novel single dominant candidate gene conferring high resistance to stripe rust races CYR30, CYR31 and CYR32. By using allelic test, it was found that this novel resistance gene in ICA56 was different from Yr5, Yr10, Yr15 and Yr26 and was designated as YrICA56. Five microsatellite markers were linked to the resistance gene YrICA56 with genetic distance WMC503-16.6 cM, Xgwm296-7.0 cM, Xgwm261-10.4 cM, WMC112-4.5 cM and Xgwm210-14.1 cM based on the F₂ population from Chuanmai28/ICA56. The order of centromere, marker primers and gene was -WMC503-Xgwm261-Xgwm296-YrICA56-WMC112-Xgwm210-centromere-. Based on the results of Mapmaker 3.0 and MapDraw 2.0, the resistance gene YrICA56 was located on 2DS. The stripe rust resistance genes Yr16 and YrKat have been located on 2DS, while Yr16 is an adult resistance gene and YrKat is temperature sensitive. Therefore, it is suggested that YrICA56 might be a new stripe rust resistance gene.