关于小麦锈菌生理专化研究方法的商榷

迄今为止,在研究锈菌生理专化和致病性方面,锈菌研究者仍然沿用活体寄主测定的方法,尚未出现根本性的变革.我国条锈鉴别寄主由重要生产品种和抗源组成,具有国际鉴别寄主同等的鉴别力.锈菌生理小种是由一个或一群生物型构成.同一小种内各菌系之间既有共性也有差异,共性是主要的,差异是较小的.小种间的差异是显著的.我们认为确定新小种应有三个相辅相成的步骤:1.发病区的田间考察.2.用鉴别主鉴定采集的标样.3.研究新菌系对小麦成株期的致病力.本文评价了传统方法的优缺点,我们认为锈菌鉴别寄主,应以一套单基因系加重要新生产品种和新抗源组成.毒力频率分析法在实践上还不能取代传统方法.

DISCUSSION ON RESEARCH METHODOLOGY OF PHY-SIOLOGIC SPECIALIZATION OF WHEAT RUST FUNGI

Up to now, scientists are still using the way of living hosts to determine the physiologic specialization and pathogenicity of the rust fungi, no foundamentally new change has been made.Differential hosts of wheat stripe rust, consisting of important cultivars and sou -rces of resistance used in China, have the same ability to discriminate as the interna -tional differential hosts. A physiologic race may consist of one biotype or a group of biotypes. Among strains in the same race, there are characters in general as well as characters in difference. It seems to author that the characters in general are of ma major importance, however, there is significant diffecence in pathogenicity between races.It is proposed that three steps should be taken to characterize a new race: 1, to investigate in fields; 2, to identify the collected samples by means of differential hosts; 3, to study the pathogenicity of a new race at the adult stage of wheat.The merits and the demerits of traditional research methods are commented. It is suggested that the differential hosts of wheat rusts should include a set of mo-nogenic lines, major commercial cultivars and the varieties with important sourse of resistance. It seems that using the method of virulence frequency analysis alone can not replace the traditional way practically.