吴江稻区稻瘟病菌小种更替规律及抗瘟品种的利用

Regularity of Race Variation of Magnaporthe grisea and Utilization of Rice Resistant Varieties in Wujiang Rice planted Region of Jiangsu Province

用７个全国统一鉴别品种对１９８０～１９９４年从吴江稻区采集的１３３份稻瘟病标样的单孢菌株进行小种鉴定，得到６群１１个小种。其中，中 Ｇ１ 小种出现频率最高，占４６５％ ，为优势小种。监测圃中稻瘟病菌小种的动态与人工接种鉴定的结果基本一致。稻瘟病菌各小种的发生频率年度间变化较大，小种的更替与栽培品种有直接的关系。通过筛选广谱抗性品种及主栽品种的抗性基因分析，初步得到１２个具有广谱抗性的品种（系），其中“９３３１”等可在生产上推广应用及作为抗源供育种部门利用。

One hundred and thirty three monoconidial isolates were segregated from rice blast specimen collected from Wujiang rice planted region during 1980—1994.The isolates were identified by 7 unitary rice varieties in China and 6 groups and 11 races were obtained.Among them,race ZG 1 was predominant with 46 5% appearance frequency.Appearance frequency of each race changed greatly in different years.Race evolution in disease nursery also showed the same trends.Analysis of the results indicated that race variation of Magnaporthe grisea were directly related to the change of the cultivated varieties.Twelve wide resitant varieties or lines were obtained through selection of wide resistant varieties and analysis of resistant genes of major varieties.Among them,some varieties such as “93 31” et al could be used as resistant source for practice and breeding.