淡紫紫孢菌菌株的分离、鉴定及其对柑橘木虱的致病性

Isolation and identification of Purpureocillium lilacinum and its pathogenicity against Diaphorina citri

从柑橘木虱中分离出一株对柑橘木虱具强致病性的菌株ZJPL08,观察该菌株的培养特征和形态特征,克隆并分析其rDNA ITS序列,并测定该菌株不同浓度的分生孢子悬浮液对柑橘木虱的致病性。结果表明：ZJPL08的菌落在PDA培养基上呈淡紫色至深紫色,富生粉质状分生孢子;3~5个轮生瓶梗,大小为（7.5~9.0）μm×（1.8~3.0）μm;分生孢子卵形或纺锤形,大小为（1.5~2.8）μm×（1.3~2.5）μm。该菌株的rDNA ITS序列与GenBank中多个淡紫紫孢菌菌株的对应序列相似性达100%,因此,菌株ZJPL08鉴定为淡紫紫孢菌。在相同浓度条件下,接种后培养时间越长,柑橘木虱的死亡率越高;培养时间相同时,孢子悬浮液浓度越高,柑橘木虱的死亡率越高。

One fungal strain was isolated from Diaphorina citri and named as ZJPL08. Cultural and morphological characteristics of strain ZJPL08 were examined,its rDNA ITS gene sequence was coloned and analyzed,and the pathogenicity of conidial suspensions at different concentrations against D. citri was determined. The results showed as follows： the color of strain ZJPL08 colony on potato dextrose agar（PDA） plate was pale purple to deep purple,and powdery conidia were produced abundantly on the colony; phialides developed at the end of the conidiophore were in whorls of 3 ~ 5,and in size of（7. 5- 9. 0） μm ×（1. 8- 3. 0） μm; Conidia was oval or fusiform and in size of（1. 5- 2. 8） μm ×（1. 3- 2. 5） μm. The rDNA ITS sequence of strain ZJPL08 shared 100% similarity with corresponding sequences of some Purpureocillium lilacinum strains deposited in GenBank. Based on the morphology and its rDNA ITS sequence,strain ZJPL08 belonged to P. lilacinum. Under the same concentration of conidial suspension,the mortality of D. citri gradually increased with the culture time prolonged. At the same culture time,with the increase of the conidial suspension concentration,the mortality of D. citri gradually increased.