三种花生根腐病菌间生物学特性及致病力的比较分析

Comparative Analysis on Microbiological Characteristics and Pathogenicity of Three Fusarium of Peanut Root Rot

对实验室前期获得的花生根腐病的病原菌尖孢镰孢菌(Fusarium oxysporum)、层出镰孢菌(Fusarium proliferatum)和茄腐镰孢菌(Fusarium solani)三种病原菌进行生物学特性分析,发现三种镰孢菌的菌落形态各异,包括菌丝致密度、气生菌丝、颜色等。小型分生孢子的产孢过程是一致的,均是在菌丝顶端缢缩形成分生孢子,但是孢子形态大小不同,表现为:尖孢镰孢菌<层出镰孢菌<茄腐镰孢菌;同时,在产孢量方面也存在着显著的差异:尖孢镰孢菌>层出镰孢菌>茄腐镰孢菌。通过三种接种方式分析了这三种镰孢菌之间的致病力差异,从离体接种到活体接种均能体现这三种镰孢菌都是致病菌,并能有效区分致病力的强弱,即尖孢镰孢菌>层出镰孢菌>茄腐镰孢菌。本研究明确了各镰孢菌间的异质性指标,为进一步研究镰孢菌对花生苗期根腐病的致病机理提供了相关依据。同时有效鉴定出强致病力菌株为尖孢镰孢菌,对其重点防治可有效减轻花生根腐病的发生,提高花生的产量及品质。

The microbiological characteristics of three previously obtained pathogens of peanut root rot,Fusarium oxysporum,Fusarium proliferatum and Fusarium solani,were analyzed.It was found that the colony morphology of the three Fusarium was different in aspects of density of mycelia,aerial mycelia,color,etc.The process of microconidia sporulation was consistent,and the conidia were formed through constriction at mycelium apex.But the spores were different in shape and size,which manifested as F.oxysporum<F.proliferatum<F.solani;in addition,there were significant differences in spore production of Fusarium spp.which manifested as F.oxysporum>F.proliferatum>F.solani.The pathogenicity of Fusarium spp.was analyzed by three inoculation methods.Both in vitro inoculation and in vivo inoculation could prove and effectively distinguish the pathogenicity of Fusarium spp.which were ranked as F.oxysporum>F.proliferatum>F.solani.The results of this study clarified the heterogeneity index among Fusarium spp.,and provided relevant basis for further research on the pathogenic mechanism of Fusarium spp.on peanut root rot at seedling stage.Furthermore,the strongest virulence strain was identified as F.oxysporum,and the emphasis on prevention and control of F.oxysporum can effectively reduce the occurrence of peanut root rot and improve the yield and quality of peanut.