【摘要】 １９９２～１９９３年从河北省６个地区采集玉米大斑病标样１２３分，分离出玉米大斑病菌株１０９份，经玉米大斑病菌生理小种鉴别寄主鉴定，１号生理小种出现频率最高为６５．１％，２号生理小种出现频率为２８．４％。２号生理小种在河北省已经普遍存在，其中唐山、承德、保定出现频率较高，分别为３６．４％、３１．６％和３０．４％．鉴定结果还可看出，从带Ｈｔ’单基因的玉米杂交种所采集的标样上２号小种出现频率较高为５８．７％。２号生理小种的出现，已对带Ｈｔ’单基因玉米杂交种造成了严重威胁，应加强抗２号小种玉米自交系的鉴定筛选及杂交种选育工作。更多还原

【Abstract】 isolates of Northern leaf blight (Helminthosporium turcicum )were isolated from the 123 samples collected in six regions of Hebei provin be from 1992 to 1993.By the test on the identification cultivars,the race I is 65.1% and Race 2 is 28.4%,among which Tang Shan,Cheng De and Baoding have higher ratest and is 36.4%,31. 6%and 30. 4%respectively. The result also showed race 2 has the higher rate 58.7% in theisolates from the hybrid samples carrying the Ht’ monogene. That happening of race 2 inHebei is becoming a serious problem to the hybrid carryillg Ht’ mono-gene. Screeningthe inbred lines resistant to race 2 is imminent.更多还原