中文摘要：

对采自雷州严重感染稻瘟病的杂交稻天优998穗颈瘟标样进行了病菌单孢分离,获得11个来自不同地点的分离物,并利用中国稻瘟病菌小种鉴别品种对分离物进行了鉴定。结果表明：11个单孢分离菌株均属于ZB3小种。选取TY1、TY4、TY21等3个菌株对广东部分品种（组合）进行了致病性测定,在测试的44个品种（组合）中,对测试菌表现高感的有天优998、博优998、博优903等11个品种组合;表现中感的有Ⅱ优3550、汕优3550、K优451、金优253、两优326、特籼占13、野丝占等7个品种组合;对测试病菌表现抗性反应的有优优122、龙优665、汕优46、粤杂763、粳籼89、粤香占、丰丝占、白香占等26个品种组合。

英文摘要：

11 single blast spore cultivated strains were isolated from a hybrid rice ＂Tian You 998＂. Race identification of these strains were conducted based on the Chinese blast differentials. The result indicated that all the isolated strains were belong to the race of ZB3. Three strains of TY1,TY4 and TY21 were used for the pathogenicity test. Of 44 tested rice varieties and combinations, 11 varieties and combinations, which including TianYou998, BoYou998, BoYou903 and so on, appeared highly susceptible to the tested pathogen. 7 of varieties and combinations, which including IIyou3550, Shanyou3550, Kyou451, Jinyou253, Liangyou326, Texianzhanl3, Yesizhan, showed moderate susceptible, 26 of varieties and combinations were resistant to the tested pathogen, they are Youyou122, Longyou665, Shanyou46, Yueza763, Jingxian89, Yuexiangzhan, Fengsizhan, Baixiangzhan and so on.