枯萎病是红花龙胆栽培中发生最普遍,危害最严重的病害之一.为明确引起红花龙胆枯萎病的病原种类及其侵染特性,本研究采用组织分离法获得2个菌株,结合形态学特征以及ITS和Mcm7序列鉴定,2个菌株被鉴定为Clarireedia jacksonii,这是该菌在龙胆科植物上引起枯萎病的首次报道.致病性测定表明,该菌在15~35℃可侵染红花龙胆健康叶片,最佳侵染温度为25℃.生长特性研究表明,该菌最适生长温度为25℃,最适pH为5,菌丝致死温度为50℃处理10 min.
Identification and biological characteristics of Clarireedia jacksonii causing wilt disease on Gentiana rhodantha in Guizhou
Wilt disease is one of the most common and serious diseases of Gentiana rhodantha in the field in Guizhou province.In order to identify the pathogen causing wilt disease on G.rhodantha,two strains were isolated from diseased leaves by tissue separation method.Based on morphological characteristics and analyses of ITS and Mcm7 sequences,the pathogen was identified as Clarireedia jacksonii.This is the first report of C.jacksonii causing wilt disease on Gentianaceae plants.Pathogenicity test showed that the pathogen could infect the healthy leaves at 15-35℃,and the optimal infection temperature was 25℃.In culture tests,the optimum conditions for mycelial growth were 25℃ and pH 5,and the lethal temperature for mycelium was 50℃ for 10 min.