土传病原真菌及其生防细菌的分离鉴定

Isolation and identification of soil-borne pathogenicfungi and biocontrol bacteria

摘要:

采用平板稀释涂抹法从甘肃农业大学草坪实训基地土壤分离得到18株真菌分离物,按照菌落形态特征将其归类为5种真菌并编号为GSAF1、2、3、4和5,通过黑麦草离体组织和皿内幼苗接种土传真菌分离物,明确了3种土传病原真菌GSAF1,4和5,根据其形态特征将它们分别鉴定为链格孢属(Alternaria sp.)、立枯丝核菌(Rhizotonia solani)和镰孢属(Fusarium sp.)。共从土壤中分离得到12株细菌分离物,编号为ZSR20-ZSR32,采用皿内拮抗法筛选到3株拮抗细菌,分别为ZSR26,30和32菌株,其中菌株ZSR30的抑菌能力略高于菌株ZSR32,对3种土传病原真菌的抑菌率均高于30%,对立枯丝核菌的抑菌率达36.2%;ZSR32菌株对3种病原真菌也有一定的抑菌作用;ZSR26对3种土传病原真菌的拮抗抑菌作用较低,抑菌率均小于20%。结合形态学和16S rDNA 分子鉴定方法,初步将ZSR26,30和32均鉴定为芽孢杆菌属(Bacillus sp.)。

Abstract:

18 strains of soil-borne fungi were isolated from the Turf Training Base of Gansu Agricultural Universityby plate dilution smearing method.According to the morphological characteristics of the colonies,theywere classified into 5 fungal isolates and coded as GSAF1,2,3,4 and 5.In which,3 soil-borne pathogenic fungi(GSAF1,4 and 5) were identified by inoculating soil-borne fungi isolates with ryegrass isolated tissues and seedlingsin dishes.According to their morphological characteristics,they were identified as Alternaria sp.,Rhizotoniasolani and Fusarium sp.respectively.12 strains of bacterial isolates were isolated from soil and coded asZSR20 to ZSR32.3 strains of antagonistic bacteria were screened by in-dish antagonism method (ZSR26,30 and32).The bacteriostatic ability of ZSR30 was slightly higher than that of ZSR32.The bacteriostatic rate of ZSR30to 3 soil-borne pathogenic fungi was higher than 30%,and the bacteriostatic rate to Rhizoctonia solani was36.2%.ZSR26 showed a low antagonistic and bacteriostatic effect on 3 soil-borne pathogenic fungi,and the bacteriostaticrate was less than 20%.ZSR26,30 and 32 were identified as Bacillus sp.by morphological and 16SrDNA molecular identification methods.This study preliminarily clarified the species of soil-borne pathogenicfungi and the relative biocontrol bacteria resources in the Turf Training Base of Gansu Agricultural University,which provided a reference for further development and utilization of biocontrol bacteria resource