云南香格里拉叉襀科昆虫病原菌的鉴定

Identification of Nemouroidea(Plecoptera)pathogen in Shangri-La,Yunnan

叉襀科Nemouroidea是襀翅目中数量最多的一个科,叉襀科昆虫也是水生生态系统环境监测的重要指示生物。为明确云南香格里拉叉襀科稚虫自然病死虫体上的病原菌并研究该病原菌对叉襀科稚虫的致病性,本研究利用常规组织分离法分离云南香格里拉叉襀科稚虫病原菌,结合形态学与分子生物学方法对两株病原菌进行鉴定,利用柯赫法则及二项式回归模型分析病原菌致病性。结果表明,菌株PN1为细囊霉菌Leptolegnia sp.,菌株PN2为冻土毛霉Mucor hiemalis;PN1及PN2处理组对叉襀科稚虫的致病性稍弱,其中PN1处理组的致病性低于PN2处理组,PN2处理组的致病性与对照组无明显差异。综上所述,本研究首次在襀翅目昆虫中报道了细囊霉菌Leptolegnia sp.和冻土毛霉M.hiemalis,两株病原真菌均属于水生弱寄生菌,在稚虫处于亚健康状态及抵抗力降低时易感,病原菌加速寄生过程使稚虫死亡。

Nemouroidea is the largest family in the order Plecoptera,and insects of Nemouroidea can be useful for aquatic ecosystem environmental monitoring as indicators.In order to identify the pathogenic in the natural dead insects of larvae of Nemouroidea from Shangri-la in Yunnan Province,we studied the pathogenicity of the pathogen to larvae of Nemouroidea.The pathogenic of larvae were separated by conventional tissue separation,and identified by morphological and molecular biology methods.And the pathogenicity of pathogenic was analyzed by Koch s law and regression model.The results showed that PN1 was Leptolegnia sp.and PN2 was Mucor hiemalis.The pathogenicity of PN1 and PN2 treated groups to larvae was slightly weaker.The pathogenicity of PN1 treated group was lower than that of PN2 treated group.The pathogenicity of PN2 treated group was not significantly different from that of control group.In conclusion,the Leptolegnia sp.and M.hiemalis reported in Plecoptera for the first time,both pathogenic fungi were aquatic weak parasites,which were susceptible when the larvae were in a sub-health state and their resistance was reduced,accelerating the parasitic process of the pathogen and causing the larvae to die.