1992~1996年我国小麦叶锈菌毒性动态

 利用已知抗叶锈病基因的小麦近等基因系(或单基因系)作鉴别寄主,监测来自我国12个省(市、区)的499份叶锈标样。结果表明:(1)在发现的诸多致病类型(毒性基因组合)中,PHT出现频率较高(26.6%),为优势类型,其余类型的出现频率均在7.4%以下;(2)毒性基因V2a、V9、V15、V19、V20、V24、V28、V29、V37、V38和V13+3Ka的出现频率小于30%,V2b、V18、V25、V27+31和V33+34的出现频率在30%~60%之间,其对应的抗性基因可视为我国小麦叶锈菌的有效抗病基因;(3)不同生态区的叶锈菌株,毒性基因(或基因组合)的组成特点、出现频率及多样性等差异较大。文中建议采用"固定鉴别基因+辅助鉴别基因"的复合鉴定系统,并对小麦抗叶锈病生态育种及抗锈基因分区部署等问题进行了讨论。

VIRULENCE DYNAMICS OF PUCCINIA RECONDITA F.SP. TRITICI IN CHINA DURING 1992-1996

499 isolates of Puccinia recondita f.sp. tritici from 12 wheat-growing areas in China were tested in 1992~1996 by using near-isogenic lines (or monogenic lines) of wheat leaf rust resistance as differentials.The results indicated,that:(1)PHT was dominant pathotype with the frequency of 26.6% while others remained less than 7.4%;(2)The frequencies of V2a,V9,V15,V19,V20,V24,V28,V37,V38 and V13+3ka were no more than 30%,followed by V2b,V18,V25,V27+31,V33+34 with the frequencies of 30%~60%,which suggested the corresponding resistance genes be effective resistance genes to wheat leaf rust in China;(3)Isolates from differently ecological regions showed obvious difference in the composition of virulence genes (or pathotypes),distribution of frequency and in their diversity.In this paper a combining system of the fixed differential genes plus supplementary differential genes for wheat leaf rust research in China was proposed,and an idea of the ecological breeding for resistance and reasonable deployment of resistance genes based on the virulence zone of Puccinia recondita f.sp. tritici in the different wheat regions was also discussed.