摘要
微菌核是大丽轮枝菌在土壤中的主要存活结构和初侵染源,在土壤中可存活14年之久,其数量及存活状况直接影响着大丽轮枝菌型黄萎病的发生为害程度。以棉花黄萎病菌Verticillium dahliae XJ2008菌株为试材,研究了微菌核萌发的最佳条件、致死温度及土壤温度对微菌核存活的影响。结果表明,20℃、pH8.0是微菌核萌发的最佳条件。大丽轮枝菌微菌核具有很强的耐高温特性,随着处理时间的延长,微菌核的萌发率呈下降趋势,在55℃及以上处理时其萌发率下降迅速,而在50℃及以下处理时其萌发率下降相对较慢,在55℃处理360min可使微菌核完全致死,而在40℃、45℃和50℃处理1,440min,仍然有少量的微菌核存活,但其萌发率随着时间的推移呈下降趋势。土壤微菌核模拟试验结果表明,土壤温度对微菌核有很强的致死作用,40℃条件下处理4d后土壤中的微菌核已全部死亡。该研究结果为通过覆膜增温防治作物黄萎病提供了理论依据。
Microsclerotia （MS） of Verticillium dahliae are main survival structure in soil and primary inoculum for Verticillium plant wilt, which may remain viable for up to 14 years in the absence of a host. The occurrence of Verticillium plant wilt was determined by the number and survival status of MS in soil. The optimal conditions for MS germination and lethal temperature were investigated by using V. dahliae strain XJ2008 as experiment material. Results showed that 20~C and pH8.0 were the optimal conditions for MS germination. MS of V. dahliae can tolerate high temperature. The germination rate of MS showed a downward trend with the extension of treat time under different temperature. The MS germination ratedeclined greatly when at and above 55~C. However, it declined slowly at and below 50~C. The MS were completely dead when treated at 55~C for 360rain. There was still a small amount of MS survival when treated at 40~C, 45~C, and 500C for 1,440min, but their germination declined gradually with time. The simulation results of MS in soil showed that soil temperature had a strong lethal effect to MS. The MS were completely lost vital when treated in soil at 400C for 4 days. The results provided a theoretical base for management of Verticillium wilts across-the-board range of crops through applying plastic film to increase soil temperature.
出处
《菌物学报》
CAS
CSCD
北大核心
2013年第6期986-992,共7页
Mycosystema
基金
陕西省自然科学基金(No.2010JM3018)
教育部新世纪优秀人才支持计划(No.NCET-07-0698)
高等学校学科创新引智计划(No.B07049)
关键词
大丽轮枝菌
微菌核
致死温度
萌发条件
Verticillium dahliae, microsclerotium, lethal temperature, germination condition
