中国小麦叶锈菌群体的毒性基因分析

 1986-1991年间，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，首次采用毒性基因频率、毒性因子（FV）、毒性值（VV）和Shannon-Wiener多样性指数等反映群体水平的参数，对我国小麦叶锈菌的毒性基因结构、频率、时间动态、空间格局及不同生理小种毒性基因的异质性等进行了比较分析。结果表明，毒性基因 V2a、V9、V15、V19、V24、V28、V29的出现频率较低（小于30%），其对应的抗性基因为目前我国小麦叶锈菌的有效抗病基因；V1、V3ka、V10、V26的频率处于升高的趋势，V2a、V15的频率有下降的趋势；不同地区叶锈菌群体的毒性因子、毒性值和毒性基因组合的多样性明显不同，我国和北美的叶锈菌至少存在4-5个毒性基因的差异；不同生理小种的毒性基因结构差异显著，叶中3号不具备V26基因，叶中34号不具有V1、V14a、V17和V27基因，而叶中4号携带有这些毒性基因。文中还对利用近等基因系作鉴别寄主的优点进行了讨论。

ANALYSIS OF VIRULENCE GENES OF PUCCINIA RECONDITA f.sp. TRITICI POPULATION IN CHINA

811 isolates of Puccinia recondita f. sp. tritici from the wheat-growing areas in China were tested during 1986-1991 by using 32 near-isogenic lines(or monogenic lines) as differentials. Virulence gene frequency, virulence factor, virulence value and Shan-non-Wiener indexes of diversity were firstly used to describe virulence difference in the leaf rust population. As shown in the results, the frequencies of virulence genes: V2a, V9, V15, V19, V24, V28 and V29 were no more than 30%, while frequencies of V12, V14a, V14b, V16, V22a, V23, V32 and V33 remained more than 90%, followed by V1, V2b, V2c, V3, V3ka, V3Bg, V10, V11, V13, V17, V18, V20, V21, V25, V26, V27, V30 with the frequencies of 38.0%-89.5%. It was suggested that corresponding resistance genes: Lr2a, Lr9, Lr15, Lr19, Lr24, Lr28, Lr29 were effective resistance genes to wheat leaf rust in China at present. V1, V3ka, V10, V26 tended to increase in frequency in the past 6 years, while those of V2a, V15 were decreased. The results also indicated the leaf rust population in the different regions were obviously different in virulence factor, virulence value and diversity of virulence gene combination, and different CLR-races possessed significantly different spectra of virulence gene. In this paper, the merits of using near-isogenic lines as differentials are also discussed.