小麦条锈菌生理小种混合侵染初步研究

前言小麦品种发生抗锈性变异一直是小麦条锈病防治的一个中心问题。国内外研究反复证实病菌小种类型的变异和数量变化是引致品种抗锈性变异的主要因素。此外,在自然界小种组成很复杂,总是多小种类型同时存在,有专有次,混合发生,据报道其它病原物的混合侵染会引起品种抗性表现的变异和症状变化,但小麦条锈菌生理小种的混合侵染是否也会引起这种变异,特别是反应型的变化,除个别文献有所涉及外,尚未见系统报

Preliminary Studies on the Mixed Infection of the Physiological Races of Wheat Stripe Rust

Five race combinations,e.g. yellow rust chinese No.1+No.8, No.1+No.20, No.1+No.21, No.19+No.20 and No.19+No.21;were used for research on the effect of the mixed inoculation in equal quantities of urediospores on the resistance of seedling and mature stages of wheat varieties as well as on the effect of the mixed inoculation with different proporties of urediospores on the resistance of seedling stage of wheat varieties. The results obtained from this test indicated that the mixed infection of races had an obvious effect on both the reaction types and severities of wheat varieties.Four phenomena of interactions between the mixed races were found,viz.,independent action,mutual additive action,synergism and antagonism.The antagonism may be divided into three cases:the strong races inhibit the weak ones,the weak races inhibit the strong ones,and their mutual inhibition.It was also found that the pathogenecity and proportion fo urediospores of mixed races may also affect the reaction types and severities of wheat varieties. The importance of mixed infection in epidemiology was discussed with some recommendations for the distribution of wheat varieties.It was also considered that the mixed inoculation should not be used in screening varieties of resistance sources or identifing the filial generations of disease resistance breeding or carrying on the genetic analysis of rust resistance varieties and variation tests of variety resistance.