利用已建立的水稻抗稻瘟病基因Pi-ta 顯性分子標(biāo)記對30 個品系和157 個來自不同國家的一些水稻品種進行分子鑒定，并采用稻瘟病菌菌株ZN57(IC-17)和ZN61(IB249)人工接種試驗進行致病性測試。結(jié)果表明，大部分品系和少數(shù)水稻品種含抗病基因Pi-ta，且對稻瘟病菌菌株ZN57和ZN61表現(xiàn)抗病反應(yīng)。除此之外，利用兩對顯性分子標(biāo)記YL155PYL87和YL183PYL87對350 個雜交F3 代株系進行早期篩選，得到118 個抗病基因Pi-ta 純合的株系。這些株系田間抗性調(diào)查結(jié)果表明，抗病基因存在與否與田間抗性相吻合。因Pi-ta 基因與許多其他抗病基因緊密連鎖，而使含有Pi-ta 基因的品種具有廣譜抗性，由此確立了Pi-ta 基因顯性分子標(biāo)記在育種輔助選擇中的應(yīng)用價值。
The dominant molecular markers of the rice blast resistance gene Pi-ta were used to identify the presence in thePi-ta gene of 30 breeding lines and 157 rice cultivars coming from some different countries1 Meanwhile pathogenicity assayswere performed with the rice blast fungus strains ZN57( IC- 17) and ZN61( IB-49)1 The results indicated that most breedinglines and several rice cultivars contained the Pi-ta gene and were resistant to strains ZN57 and ZN611 In addition, two pairsof dominant markers YL155PYL87 and YL183PYL87 were used to screen the resistant breeding lines at the early stage1 Onehundred and eighteen lines containing homozygous Pi-ta gene were isolated from 350 F3 breeding lines1 At the same time,the rice blast resistances of these lines in the field were investigated1 The results demonstrated that the Pi-ta presence consistedwith the resistance in the field1 Considering that Pi-ta is closely linked with other blast resistance genes, the Pi-tagene markers is very useful for marker- assisted selection