小麦条锈菌鉴别寄主和小种命名现状

 中国是世界上小麦条锈病最大的流行区之一,也是限制中国小麦生产的最严重病害之一,特别是当条件适于其发生时会造成巨大的产量损失.小麦条锈菌小种生理专化性研究及小种监测是掌握小麦条锈菌及其毒性变化动态、抗病基因有效性及病害流行预测预报的重要依据,是治理由此病原菌引起的小麦条锈病的基本环节之一.由于地域、条锈菌群体结构、研究水平和历史等的差异,目前国际上不同国家和地区采用相应的小麦条锈菌鉴别寄主和小种命名方法.中国、美国和印度均使用了各自不同的小麦条锈菌鉴别寄主,并采用了相应的小种命名体系,例如从1957至2002年,中国利用10多个鉴别寄主已鉴定和命名了32个小种和30多个致病类型,美国利用10多个鉴别寄主已鉴定和命名了80个小种;另一类是采用1972年Johnson提出的二进制国际小种命名法,这种体系包括了国际鉴别寄主和欧洲鉴别寄主,象一套鉴别寄主被整体使用,欧洲、中东、亚洲、非洲和南美国家及澳大利亚和新西兰均采用此体系监测小麦条锈菌变化,是一套被最为广泛接受和使用的小麦条锈菌小种鉴别方法和命名系统,但随着研究深入和各国实际情况差异等原因,不同研究人员加入了不同的辅助鉴别寄主,以更能准确和实际地反映本国和地区的现实情况,为生产服务,本文对此现状进行了分析和比较.由于此病菌具有长距离气传和扩散的特点(地区间、国家间和洲际间),因而也讨论了未来小麦条锈菌鉴别寄主组成、小种命名方法和研究结果的交流和比较等实际问题.

Differentials and nomenclature of races of Puccinia striiformis West. F.sp.tritici Eriksson

China is one of the largest counties where epidemics of wheat stripe rust (Puccinia striiformis West. f. sp. tritici Eriksson) causes a big problem in wheat production. The disease is a great threat in many wheat-growing areas, espe- cially when conditions are favorable to the disease epidemics. Studying the physiological specialization and monitoring dy- namics of races of P. striiformis West. f. sp. tritici Eriksson is important to understand the variation of the pathogen and its virulence, effectiveness of resistance genes in disease control, prediction of stripe rust epidemics, as well as disease management. Due to the variation of geographic and regional characteristics, diversity of population structures of the pathogen, and so forth, different countries use differential host differentials and nomenclature system of races of P. stri- iformis. China, United State of America and India have their own differential hosts and nomenclature systems of races re- spectively. In China, 32 races and more than 30 pathotypes were identified by using relatively stable Chinese differentials during 1957 - 2002, while in the US 80 races were identified by using US differentials until now. Another system of nomen- clature of races was put forwarded by Johnson in 1972. In this system both world and European differentials were included as integrate differentials. This system is widely accepted and employed in Europe, Middle East, Asia, Africa, South Ameri- ca countries, Australia and New Zealand etc. In considering the variability in different countries and regions, additional differentials were added into this system by various rust researchers around the world. In addition to the long-distance di- spersal of the pathogen spores and disease spread, the possible future developments in this area including differential compo- sition, method of race nomenclature, as well as the international communications among scientists in this research area are also discussed.