1993年全国小麦秆锈菌种群动态分析

RACE DYNAMIC OF PUCCINIA GRAMINIS F. SP. TRITICI IN CHINA IN 1993

1993年我国小麦秆锈病发生较轻,从8个省18个区县中的47个品种上采集到的95个标样中分离到菌株336个,鉴定出21C3CKR、21C3CKH、21C3CTR、21C3CTH、21C3CFR、21C3CFH、34C1MKR、34C1MKH和34C2MKR等9个致病类型;21C3CKR的出现频率为65.2％,居于首位,21C3CKH为14.5％,21C3CTR为10.7％,21C3CFR为4.2％,21C3CTH为1.2％,其余各致病类型均在0.9％以下。首次发现对Sr11有毒力的菌株,利用336个菌株对41个Sr单抗基因的毒力频率测定中,毒力频率在19.8％以下的有Sr5、10、11、15、26、31、33、35、37和38,其中对Sr11的毒力频率为14.6％;毒力频率在40％—58.2％之间的Sr单基因系是Sr24、32、GT和SrWld-1;全部菌株对Sr9e、21和30没有毒力,其余Sr单基因系的毒力频率均在67％以上。

The incidence of wheat stem rust was not severe in China in 1993 except partial regions, such as in Yuanmou County of Yunnan Province and in part of Sichuan Province where moderate epidemics occured. All of the 336 isolates for tests were obtained from 95 uredial samples collected from 47 different wheat cultivars distributed in 18 counties of 8 provinces. These isolates were identified and categorized into 9 patho-types, ie. 21C3CKR, 21C3CKH, 21C3CTR, 21C3CTH, 21C3CFR, 21C3CFH, 34C1MKR, 34C1MKH and 34C2MKR. The 21C3CKR was dominant race with a frequency of 62. 5%. Sequentially following it were 21C3CKH (45. 5%),21C3CTR (10. 7%),21C3CFR (4. 2%) ,21C3CTH(1. 2%). The frequency of rest four pathotypes was no more than 0. 9%. The isolates virulent to Sr11 were firstly detected in China. The virulence frequencies of all 336 isolates on 41 Single Sr gene lines was tested. Results showed that the virulence frequencies on Sr5,10,11,15,31,33,35,37 and 38 were below 19. 8%,on Sr11 was 14. 6%,and on Sr24,32,GT and Sr Wld-1 were between 40% -58. 2%. No virulent isolate was found on Sr9e, 21 and 30 while the frequencies of virulence to 25 single Sr gene lines was above 67%.