中国条锈菌新小种条中30、31号的研究

本文报道了1991年以来对新小种条中30、31号鉴定与致病性的研究。继1991年发现对绵阳系成株小麦有致病力的、对Hybrid46有毒的新致病类型91—1,1993年又发现了新的致病类型93—1。根据它们对我国鉴别寄主的反应,命名为条中30、31号。与条中28、29号相比,新小种具有更宽毒性基因组成和更高的相对寄生适合度值,它们对我国生产品种、高代品系和重要抗源有更广的致病范围。证实两个新小种的出现和发展是绵阳系小麦抗条锈变异的主要因素,建议加强对新小种抗病育种和流行预测的研究。

THE DISCOVERY AND STUDIES ON NEW RACES CYR30 AND CYR31 OF WHEAT STRIPE RUST IN CHINA

This is a report on identification and study of pathogenicity of new races CYR30 and CYR31 of wheat stripe rust (Puccinia striiformis West)since 1991. The pathotype 91-1 was found firstly in 1991,and pathotype 93-1 was discovered in 1993. They were virulent to cultivar hybrid 46. Based on their reaction on differential hosts, pathotypes 91-1 and 93-1 were named as Chinese Yellow Rust races 30 and 31 (or CYR30 and CYR31) respectively. Compared with current dominant races CYR28 and CYR29,the new ones possessed wider spectrum of virulence genes, higher value of the relative parasite fitness to the important commercial varieties, and more extensive range of pathogenicity to some wheat cultivars stock varieties and important resistant resources. The emergence and development of the two races were confirmed to be the major factor for the variation of stripe rust resistance of cultivars Mianyang series. Breeding for resistance and studies on the epidemic forecast to the new races of stripe rust are urgently needed