源自杂交稻组合五优308 稻瘟病菌致病性分析

对采自广东韶关、河源、梅州等稻区严重感染稻瘟病的杂交稻组合五优308穗瘟标样进行了稻瘟病菌分离,获得源自不同地点的穗瘟标样分离物18个,利用7个中国稻瘟病菌小种鉴别品种和11个单基因系对分离物进行了致病性分析.结果表明:所分离菌株鉴定出ZB13、ZB15、ZC13等3个小种,分别占分离菌株的66.67％、27.78％、5.56％;对分离菌株表现出高感的抗性基因有Pi-ta2、Pi-sh、Pi-i,对分离菌株具有抗性较好的基因有Pi-kh、Pi-1、Pi2、Pi-9及Pi-50等;所有分离物均能回接上杂交稻五优308,使接种品种表现感病.选取GDHY-308-1401等3个菌株对广东部分品种(组合)进行了致病性测定,在测定的45个品种(组合)中,表现感至高感的品种(组合)有13个,占28.89％;中感的有2个,占4.44％;中抗至高抗的有30个,占66.67％.其中与五优308同一类型的杂交稻组合五丰优9802、五优613、五优1179对接种菌株表现出良好抗性,在五优308感病的稻区可考虑种植上述抗病品种.

Pathogenicity analysis on Magnaporthe grisea of hybrid combination Wuyou308

Eighteen blast isolates were obtained from a hybrid combination Wuyou308 using the Magnaporthe oryzae pathogen isolation method. Race identification of these isolates was conducted based on 7 Chinese blast differentials and 11 blast monogenic lines. The results indicated that the isolates were identified as the race of ZB13, ZB15, ZC13, accounting for 66.67%, 27.78%, 5.56%, respectively, the resistance genes including Pi-ta2, Pi-sh, Pi-i were highly susceptible to these isolates, while the resistance genes like Pi-kh, Pi-1, Pi2, Pi-9 and Pi-50 showed good resistant to tested pathogens. All isolates were compatible to the original rice of hybrid Wuyou308. Three isolates like GDHY-308-1401 and so on were used for testing their pathogenicities to 45 local varieties. The results demonstrated that 13 varieties appeared highly susceptible to the tested isolates, accounting for 28.89%; two varieties appeared moderately susceptible to the tested isolates, accounting for 4.44%; 30 varieties appeared moderately/highly resistance, accounting for 66.67%. Among them, some of new hybrid combinations such as Wufengyou9802, Wuyou613, Wuyou1179 showed good resistance to the inoculated strains, they were recommended to be the candidates in the rice region where Wuyou308 showed susceptibility