一株来自青藏高原土壤日本曲霉菌的分离鉴定及其杀东亚飞蝗活性研究

采用稀释涂布法从青藏高原采集的土样中分离得到一株具有杀蝗虫活性真菌D3-19.通过形态学观察以及ITS序列的分析,初步将D3-19鉴定为曲霉属日本曲霉(Aspergillus japonicas).室内活性测定结果表明日本曲霉D3-19发酵液和孢子均有杀东亚飞蝗活性.其中,真菌发酵液对东亚飞蝗校正死亡率为:96h(86.67%),144h(100%).与此同时,真菌孢子悬液对东亚飞蝗的LC50(致死中浓度)为3.42×105孢子/mL.研究结果表明,3×108孢子/mL的D3-19孢子悬液对不同年龄阶段东亚飞蝗均有致死效果.其LT50(半致死时间)值分别为:羽化成虫(155h),四至五龄成虫(104.8h),三龄幼虫(54.6h),二龄幼虫(30.6h).

Investigation on the insecticidal potential of Aspergillus japonicas D-19 isolated from the Tibetan plateau against Locusta migratoria manilensis (Meyen) (Orthoptera: Acrididae)

By using dilution coating method a fungus D3-19 with insecticidal activity against locusts was isolated from soil of the Qinghai-Tibet Plateau. By the morphological observation and ITS sequence analysis, D3-19 was preliminary identification as A.japonicas. Indoor bioassay results showed that both fermentation liquor and conidial suspension of A.japonicas D3-19 had insecticidal activity against L. migratoria. For 96 and 144 h of treatment, The corrected mortalities of the A. japonicas D3-19 fermentation liquor against L.migratoriawere 86.67% and 100%, respectively. Meanwhile, the LC 50 value of L.migratoria to the A. japonicas D3-19 conidia suspension was 3.42×10 5 conidia/mL. The result showed that, 3×10 8 conidia/mL conidial suspension of A. japonicas D3-19 had insecticidal activity against all life stages of L. migratoria, and the LT 50 (median lethal time) values of emerging adults, fourth to fifth instars, third instars larvae, and second instars larvae were 155 h, 104.8 h, 54.6 h, and 30.6 h, respectively.