豇豆枯萎病病原分离鉴定

Identification of Fusarium sp.from cowpea

通过采集武汉市豇豆种植区豇豆枯萎病病株,经常规组织分离法分离纯化获得菌株JKW-1、JKW-2和JKW-3,并对3个菌株进行致病性测定、形态学及分子生物学鉴定.结果表明,3个菌株均为致病的镰刀菌,其中菌株JKW-1和JKW-2菌落色泽为紫红色,JKW-3菌落色泽为白色,均能产生大型分生孢子、小型分生孢子和厚垣孢子,但在菌落形态、产孢量、分生孢子大小等方面存在差异;对这3个菌株的核糖体RNA基因内转录间隔区(rDNA-ITS)进行了PCR扩增和序列测定,并在GenBank中进行Blast搜索和比对分析,根据rDNA-ITS序列分析结果结合豇豆病株症状和病菌的形态学特征,判定引起武汉市豇豆枯萎病的病原菌为尖孢镰刀菌(Fusarium oxysporum Schl.).

Three fungal isolates,JKW-1,JKW-2 and JKW-3,from Fusarium wilt of cowpea,which were collected from Wuhan City,were studied on pathogenicity,morphology and molecular identification.The results showed that three strains were pathogenic Fusarium.Strains JKW-1 and JKW-2 colony color were purple,whereas JKW-3 colony color was white.The three isolates could produce microconidia,macroconidia and chlamydospore,which existed differences from colonial morphology,sporulation and spores size.The rDNA-ITS genes from the three isolates were amplified and sequenced.Based on the Blast search and the alignment analysis in GenBank database combined with morphological characters,the pathogen of cowpea blight was identified as Fusarium oxysporum Schl.