Abstract: Four hundred eighty one rice blast specimen were collected from 55 varieties planted in 11 counties (or cities or divisions) in Wenzhou rice region during 1991-1993, and 354 single conidia isolates were obtained. The isolates were assessed on 7 Chinese differential varieties, and 7 groups and 23 races were identified. Among them, group ZB was predominant with 80.23% of isolated frequency. The predominant races were ZB1, ZB9 and ZB13. The kinds of races had much changed compared with the general survey during 1981-1984. The races isolated from major varieties cultured in Wenzhou region were analysed. There was specificity in the race-variety interaction, so different races were detected depending on the varieties. The resistance of 11 major varieties to the tested isolates of Wenzhou region was examined. Varieties Shanyou 10 and Fuxin 6 had higher resistance, showing over 76% resistant frequency. Other tested varieties showed low resistant frequency. The resistant frequency of most major varieties to the predominant races was lower than to general isolates. Predominant races ZB1, ZB9 and ZB13 were of strong virulent to the major varieties in this rice region. It was important and urgent that breeding or introducing fine varieties with resistance to group ZB, especially to race ZB1, ZB9 and ZB13.

Key words: Pyricularia grisea, race evolution, variety resistance

摘要： 1991～1993年从温州稻区11个县(市、区)55个不同品种上采集481份稻瘟病标样，分离到354个单孢菌株，经7个中国稻瘟病菌鉴别品种鉴定，共检出7群23个小种，ZB群小种的分离频率较高，为80.23%，优势小种为ZB1、ZB9和ZB1３。与1981～1984年的小种普查结果相比，小种类型和结构发生了较大的变化。从温州稻区主栽品种病标样上分离的小种看，不同品种上的小种组成有差异，品种和小种之间存在着特定的亲和性关系。对温州稻区11个主栽品种的抗谱测定结果表明，汕优10号和辐籼6号的抗性较优，总体抗谱在76%以上，其他品种的抗谱均较差；多数主栽品种对优势小种的抗谱低于总体抗谱水平，该稻区的优势小种ZB1、ZB9和ZB13对主栽品种具有较强的致病性。选育或引进抗ZB群，尤其是ZB1、ZB9和ZB13小种的品种显得非常迫切和重要。

关键词: 稻瘟病菌, 小种演变, 品种抗性