持久抗病基因Yr18在中国小麦抗条锈育种中的应用

持久抗病基因Lr34/Yr18/pm38赋予小麦对叶锈、条锈和白粉的广谱抗性。为明确该基因在我国的分布及应用状况,对495份生产小麦品种或高代系和30份小麦核心种质进行了抗病鉴定,并以该基因特异性标记cssfr3和cssfr5对Lr34/Yr18/pm38位点进行精确检测。结果显示,Lr34/Yr18/pm38基因位点在成株期对我国所有小种都表现中度抗病。分子检测结果显示,Lr34/Yr18/pm38基因位点在生产品种和高代品系中比例很低,只有2.02%;而在核心种质中的比例却很高,达到13.3%。这表明,这一基因位点曾在我国广泛应用,但在随后的育种过程中逐步丢失。

Application of Durable Resistance GeneYr18to Stripe Rust in Chinese Wheat Breeding

The gene locus Lr34/Yr18/pm38,conferring broad spectrum resistances to leaf rust,stripe rust,and powdery mildew,is present in a large number of wheat cultivars.To verify the distribution of this locus among Chinese cultivars,two new sets of Gene-specific markers(cssfr3 and cssfr5) were used for unambiguous identification of Lr34/Yr18/pm38 in a variety of wheat genotypes.A total of 525 entries,including 495 wheat cultivars and advanced lines,a core collection of 30 lines which were widely used historical varieties,were evaluated for their stripe rust resistance.The results showed the Lr34/Yr18/pm38 gene locus maintained moderate resistance to the major prevalent Chinese stripe rust races at the adult stage.After screening with molecular markers,the proportion of the lines with Lr34/Yr18/pm38 gene locus among the tested cultivars and advanced lines was only 2.02%,while 4 of 30(13.3%) lines in the core collection contained this Lr34/Yr18/pm38 gene locus.The fact that the ratio of wheat genotypes carrying Lr34/Yr18/pm38 in the core collection was much greater than that in the cultivars and advanced lines,implied that this gene locus had been widely used previously.