小麦混合品种对条锈叶锈及白粉病的群体抗病性研究

 本文以小麦感病品种津丰一号和抗病品种冀麦24号为材料,研究了两者在混合种植情况下,对条锈叶锈及白粉病的群体抗性机制。结果表明群体抗性由密度效应、阻挡效应和诱导抗性效应组成,其中密度效应自始至终发挥着主要作用,其它两种机制均是在生长季节后期才表现明显。同一抗性机制在不同种病害上所表现的程度也有所不同。

THE POPULATION RESISTANCE OF WHEAT VARIETY MIXTURE TO PUCCINIA STRⅡFORMIS, P. RECONDITA AND ERYSIPHE GRAMINIS

The mechanisms of population resistance of wheat variety mixture to Puccinia stri-iformis, P. recondita and Erysiphe graminisa had been studied by field experiments. The two components of variety mixture were Jinfeng 1 (susceptible cv.) and Jimai 24 (resistant cv.). The results showed that the population resistance might be partitioned into three parts:the influence of the reduced density of the susceptible plants, the barrier effect of the resistant plants, and the induced resistance due to the non-virulent pathogen bio-types. From the on-set to the end of the epidemic, the lower density of susceptible plants accounted for most of the reduction in disease development in mixtures. As the epidemic progressed, the barrier effect and induced resistance increased in importance. The relative importance of each mechanism varied according to different diseases.