利用分子标记辅助筛选改良‘泸恢602’稻瘟病抗性的研究

Preliminary study on accelerated improvement of rice blast resistance of Luhui 602 using molecular marker-assisted selection

水稻抗稻瘟病基因Pi9(t)抗谱广、抗性强。以携带抗稻瘟病基因Pi9(t)的小粒野生稻Oryza minuta为抗源,以优良杂交稻恢复系‘泸恢602’为轮回受体亲本,通过杂交及选择与受体亲本相似单株连续回交,直至BC3F1,令其自交。在分离群体中利用与Pi9(t)紧密连锁的标记PB8进行分子标记辅助选择,并结合株型、粒型、播抽期等农艺性状与‘泸恢602’相似株的选择,在BC3F4代,获得15份Pi9(t)基因纯合且农艺性状与‘泸恢602’相似的单株。用120对SSR引物进行背景选择,决选出6个单株,作为改良的‘泸恢602’。以四川近年来具有代表性的32个菌株对这6份材料进行抗性鉴定,其抗性频率75.00%～87.50%,表明抗性基因已成功导入‘泸恢602’中并表达。

Luhui 602 is a heat resistant and high-power recovery line,but has less resistance to the rice blast.Rice blast resistance gene Pi9（t） showed a broad spectrum of strong resistance.In order to improve the resistance of Luhui 602,Oryza minuta which has Pi9（t） gene was carried as the anti-source,and Luhui 602 as the recipient and transmigrate parent through hybridization and resumption of diplomatic relations,and made it self-hybrid until BC3F1.The marker PB8 tightly linked to Pi9（t） was used to select in the separate groups combined with plant type,grain type,maturity and other agronomic traits similar to strains with Luhui 602.In BC3F4,15 plants were obtained with homozygous Pi9（t） gene and similar agricultural features to Luhui 602.Background selection was carried out with 120 pairs SSR primers,and six plants were screened out as the improved line of Luhui 602.Resistance of these 6 improved line were identified use 32 blast isolates collected in Sichuan Province,and the resistance frequency were 75.00%-87.50%,which identified that the resistance gene had been imported in Luhui 602 successfully and expressed.