萝卜蚜新蚜虫疠霉的分离鉴定及其致病性测定

目的]分离鉴定萝卜蚜的病原真菌,并测定其对萝卜蚜的致病性。方法]采用形态学方法进行病原真菌种类鉴定,利用孢子浴方法对萝卜蚜进行致病性测定。结果]初生分生孢子,卵形,双囊壁,单核,（24.7±1.4）μm×（10.7±0.9）μm,L/D=2.3±0.2。次生分生孢子形似初生分生孢子,大小为：（18.6±2.1）μm×（13.3±1.3）μm,L/D=1.4±0.2。菌丝段菌丝状,直径为（10.6±0.8）μm。分生孢子梗掌状分枝,直径（10.0±0.9）μm。假囊状体不分枝,基部粗大,直径（19.2±1.7）μm,向端部渐尖,直径（8.0±0.9）μm。假根单菌丝状,基部直径（21.0±3.0）μm,底端具有规则的盘状固着器。休眠孢子未见。该菌对萝卜蚜的致死中量为18.21 cfu/mm2。结论]感染萝卜蚜的昆虫病原真菌被鉴定为新蚜虫疠霉,该菌对萝卜蚜表现出较强的致病性。

Isolation and Identification of Pandora neoaphidis and Its Pathogenicity Against Lipaphis erysimi

Objective]The study was to isolate and identify the pathogen of Lipaphis erysimi and to determine its pathogenicity against L.erysimi.Method]Based on the morphological characteristics,the species of pathogenic fungus was identified.Spore shower method was used to deter mine the pathogeni-city against L.erysimi.Result]Primary conidia,ovoid,bitunicate and uninucleate,(24.7±1.4) μm×(10.7±0.9) μm,L/D=2.3±0.2.Sencondary conidia had the similar shape with the primary ones,(18.6±2.1) μm×(13.3±1.3) μm,L/D =1.4±0.2.Hyphal fragment was like mycelium with the diameter of(10.6±0.8) μm.Conidiophores had palmate branch with the diameter of(10.0±0.9) μm.False cystidia was not branched,which had rough base with the diameter of(19.2±1.7) μm,and gradually became more angular towards the apex with the diameter of(8.0±0.9) μm diameter at tips.Rhizoid was like monohyphal shape with the diameter of(21.0±3.0) μm at base,the terminal apex had regular discoid holdfast.No dormancy spores was observed.The lethal dose of the pathogen against L.erysimi was 18.21 cfu/mm2.Conclusion]The entomopathogenic fungus against L.erysimi was identified to be Pandora neoaphidis,and the pathogen was confirmed to have strong pathogenicity against L.erysimi.