子预44中抗稻瘟病基因Pi-zy3(t)的定位

Identification of Pi-zy3(t) Gene Conferring Resistance to Rice Blast Isolate LP33 in Ziyu44

稻瘟病是影响水稻高产、稳产、优质的重要病害。广谱持久抗瘟品种的培育和利用是防治稻瘟病最经济有效的措施之一,但广谱持久抗性分子机制还不清楚。子预44是一具有广谱持久稻瘟病抗性的云南地方粳稻品种,对其抗瘟基因的鉴定将有助于揭示其抗瘟分子机制。本研究通过利用子预44和感病水稻江南香糯杂交构建F2遗传群体,稻瘟病菌株LP33苗期喷雾接种亲本预44、江南香糯及F2代单株,对其抗性进行评价和主效抗瘟基因定位。研究结果显示:子预44表现高抗,江南香糯高感;F2群体稻瘟病抗感分离符合3:1的分离比,即子预44对LP33的抗性为单显性基因控制的抗性遗传,并将该基因暂定名为Pi-zy3(t)。进一步利用SSR分子标记将Pi-zy3(t)定位在水稻第六号染色体RM276到RM3827之间,为进一步的基因克隆和抗病机分子制研究奠定了基础,同时也为利用子预44进行抗病分子育种提供了辅助选择的分子标记。

R ice blast is one of the most severe diseases in rice production and causes serious yield losses and quality decreasing. Development and use of broad-spectrum durable resistant varieties is considered as the most effective and economical strategy to control this disease, but the mechanism of broad-spectrum durable blast resistance is not clear. The japonica rice cultivar Ziyu44 confers broad-spectrum durable resistance to blast.Identification and cloning of resistance genes in Ziyu44 will benefit to investigate the molecular basis of broad-spectrum durable resistance. In this study, we developed an F2 population from the cross between Ziyu44 and JNXN. The F2 progenies, Ziyu44 and JNXN, were inoculated with the blast isolate LP33 for blast disease evaluation. The results showed that Ziyu44 conferred high level resistance to LP33, and JNXN showed high susceptibility to LP33. The segregation of resistant and susceptible plants in F2 population agreed with the ratios of3：1, indicating that the blast resistance of Ziyu44 to LP33 is controlled by a single dominant gene, temporarily designated Pi-zy3（t）. Further linkage analysis using susceptible F2 individuals, Pi-zy3（t） was located on rice chromosome 6 closed to the centromere between SSR markers RM276 and RM3827. These results provide essential information for the cloning of the Pi-zy3（t） gene and will facilitate marker-assisted selection in rice breeding.