小麦及禾草条銹病菌的研究

 山西晉中一带麦田边生有大量碱草(Elymus chinense),严重感染条锈病。接种試驗証明小麦条銹菌与碱草条銹菌在致病力方面有显著差异。碱草对14个小麦条銹菌种均抵抗,碱草条銹菌虽能侵染小麦,但13个小麦推广品种对所有5个碱草菌种都表現抵抗。田間調查結果亦示明碱草条銹菌虽能侵染小麦,但麦叶仅产生抗性的枯斑及形成极少量的夏孢子堆,并証实其不能在小麦上继續繁殖。不同小麦的种对碱草条锈菌亦均免疫或高度抵抗。小麦条銹菌能侵染冰草(Agropyron cristatum)等11种禾草,其中旱雀麦(Bromus tectorum)及西伯利亚碱草,(Elymus sibiricus)高度感染。碱草条銹菌較小麦条銹菌能适应更高的气温,在25℃仍能正常侵染碱草且产生大量孢子堆,其夏孢子(28.94μ×22.41μ)亦显著較小麦条銹菌的夏孢子(26.10 μ×19.48μ)为大,因此是条銹菌(Puccinia glumarum)的一个較为特殊的生理小种(YIE)。西伯利亚碱草(Elymus sibiricus)、山大麦及麦穗草(Agropyron spp.)的条銹菌均能正常侵染小麦,但尚未发現其大量感染条銹病的羣落。

A STUDY ON STRIPE RUST OF WHEAT AND GRASSES

The wide occurrence of Elymus chinense heavily infected with Puccinia glumarum, was found around wheat fields in central part of Shensi Province.
It was proved experimentally that the stripe rust on E. chinense differed greatly from that on wheat in pathogenicity as well as in uredospore Mearurement, and the former was identified as a biological race of P. glumarum (race YIE). E. chinense was resistant to 14 stripe rust collections from wheat while 13 improved varieties of wheat were resistant to 5 stripe rust collections from E. chinense. Field observations also verified that infections of wheat due to uredospores of race YlE all developed highly resistant infection types with only, scanty sporulatiou. Successive incculation starting with large amount of uredospores showed that race YlE could not perpetuate on wheat beyond 5 uredospore generations. Different wheat species of wide genetic diversity were either immune or highly resistant to race YlE. Stripe rust from wheat could attack different species of grasses, among which Bromus teciorum and E. sibiricus were highly susceptible.
Race YlE could tolerate much higher temperature than races collected from wheat varieties and prolific sporulation was obtained at 25℃.
Stripe rust from E. sibiricus and Agropyron spp. severely attacked seedlings of many wheat varieties. The practical importance of these grasses to the perpetuation of these biological races of stripe rust needs further study.