番茄褐斑病菌的侵染条件及致病性研究

Infection factors and pathogenicity of Helminthosporium carposaprum

对番茄褐斑病菌侵染条件及致病件的研究表明，温度与保湿时间对番茄褐斑病菌（Helminthosporium carposaprum）的侵染有很大的影响。当温度为10℃时，病原菌潜育期达74h；当温度为25～30℃时，潜育期仅为6．0～8．0h。叶面保湿时间愈长，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25～30℃，保湿时间24～48h。不同番茄品种对病菌的敏感性差异较显著，世纪、夏丰为高度感病品种，百果强丰和博爱15号为中抗品种、霸王、皖粉3号和皖粉4号为抗病品种。不同菌龄的H．carposaprum对番茄的致病性也有差异，菌株培养10d时的致病力较强，培养15d的致病力次之一培养5d和培养20d的菌株致病力较差。

Temperature and wetness periods greatly affected the infection of Helminthosporium carposaprum. When temperature was 10℃,the incubation period was 74h. When temperature was from 25℃ to 30℃ ,the incubation period was only from 6.0 h to 8.0 h. The least wetness period was about 6 h. The favorite combination of temperature and wetness period for infection was that temperature was from 25℃ to 30℃ and wetness period from 24 h to 48 h. The susceptibility tests of different varieties of tomato to Helminthosporium carposaprum indicated that Shiji and Xiafeng were more susceptible than others. The pathogenicity tests of different period isolates showed that 10 dhc was stronger than others.