烘烤期烟叶霉烂病的侵染源与防治

目的]明确烘烤期烟叶霉烂病的症状、病因、侵染源和防治措施。方法]通过病原形态学观察、生物学特性观察和ITS-PCR检测分析,对烘烤期烟叶霉烂病的病原进行鉴定,并用二氧化氯和三氯异氰脲酸对烟柄喷雾或熏蒸装烟后的烤房,研究其对烘烤期烟叶霉烂病的防治效果。结果]烘烤期烟叶霉烂病的病原鉴定为米根霉(Rhizopus oryzae)。利用PSA平板采集烤房内外及烟叶表面的微生物,米根霉广泛存在于烤房内外的环境中,能在烤房内存活和积累成为重要侵染源。用二氧化氯和三氯异氰脲酸对烟柄喷雾或熏蒸装烟后的烤房,结果显示熏蒸法对烘烤期烟叶霉烂病的防治效果在62.62%~69.57%。结论]为烟叶霉烂病的有效防治提供了理论依据。

Control and Infection Source of Tobacco Leaf Mildew Rot during Flue-curing Period

Objective]The aim was to explore the symptoms, causes, infection source and control ways of tobacco leaf mildew rot disease. Method]The pathogen of tobacco leaf mildew rot disease was identified by the ITS-PCR sequence analysis combined the morphological characters and biologic characters. The disinfectants chlorine dioxide and trichloroisocyanuric acid were used to control the disease by spraying to tobacco stalks and fumigation in curing barns. Result]The pathogen was identified as Rhizopus oryzae. The microbial flora in the curing surroundings and tobacco leaf were isolated and analyzed by PSA plate culture, the results showed Rhizopus oryzae was widespread in the curing barns and their surroundings, the fungi could accumulate in the curing barns and were the important infection sources. The disinfectants chlorine dioxide and trichloroisocyanuric acid were used to control the disease by spraying to tobacco stalks and fumigation in curing barns, the disinfectants fumigation could effectively control the disease, and the control effect were up to 62.62%-69.57%. Conclusion]The results provide theoretical basis for the control of tobacco leaf mildew rot disease.