苹果链格孢菌侵染条件及致病性研究

The Infection Factors and Pathogenicity of Alternaria mall Roberts

温度与保湿时间对苹果链格孢菌的侵染有很大的影响.当温度低于10℃,病原菌潜育期需72h;但当温度为25～30℃时,潜育期仅为6.5～8h.叶面保漫时间愈长,愈利于病原菌的侵染,叶面最少保湿时间为6h.病原菌侵染的最佳温度和保湿时间组合为:温度28～32℃,保湿时间24～48h.不同菌株接种试验表明:各菌株致病性有一定的差异,兰1、天2、平3菌株致病性较强,而武4菌株致病性较弱.品种感病性差异显著.印度、红星最易感病,祝、乔纳金抗病性较强.

Temperature and wetness periods greatly effect the infection of Alternaria mali.When temperature is lower than 10℃,the incubation period is 72hr. When temperature is from 25 to30℃,the incubation period is only from 6.5hr to 8hr. The longer wetness period on leaf surface is useful for infection. The least wetness period is about 6h. The favorite combination of temperature and wetness period for infection is that temperature is from 28 to 32℃ and wetness period from 24 to 48h. The pathogenicity tests of various isolates show that Lan-1,Tian-2 and Pin-3 have stronger virulence and weaker in Wu-4. The susceptibility tests of different varieties of apples to Alternaria mali indicate that India and Delicious have more susceptibility than others.