红火蚁病原真菌分离鉴定及致病性研究

Isolation, identification and pathogenicity of entomogenous fungi to red imported fire ant Solenopsis invicta

红火蚁Solenopsis invicta是世界上最具破坏力和威胁性的入侵检疫害虫之一,对农林业生产安全、公共设施以及人体健康都造成了巨大影响。为筛选对红火蚁有致病性的病原真菌,本研究通过组织分离法对自然罹病的红火蚁进行致病菌分离,结合病原形态学及分子生物学的方法对病原真菌进行鉴定并采用喷雾法测定了病原真菌对红火蚁的致病力。结果表明:从罹病红火蚁上分离出3株病原真菌HHYSFJ01、HHYSFJ02和HHYSFJ05,分别为红绶曲霉Aspergillus nomius、淡紫拟青霉Purpureocillium lilacinum和球孢白僵菌Beauveria bassiana。致病性测定,这3株病原菌对红火蚁均具有较强的致病性,且3株病原菌致病性间差异显著。经1.0×108孢子/mL孢子悬浮液喷雾处理红火蚁10 d后,球孢白僵菌菌株HHYSFJ05的致病性最强,红火蚁工蚁的校正死亡率为84.71%,LT50为4.67 d;红绶曲霉菌株HHYSFJ01和淡紫拟青霉菌株HHYSFJ02次之,红火蚁工蚁的校正死亡率分别为78.82%和73.29%,LT50分别为4.99 d和5.20 d。

Red imported fire ant( RIFA) was one of the most destructive and threatening intrusion inspection and quarantine pests in the world, which has a huge impact on agricultural and forestry production safety, public facilities and human health. In order to screen for entomogenous fungi that were pathogenic to RIFA, in this study, the tissue separation method was used to isolate the pathogenic bacteria of RIFA that naturally diseased, combining pathogen morphology and molecular biology methods to identify entomogenous fungi of RIFA and using the spray method to determine the pathogenicity of RIFA entomogenous fungi. The results showed that three strains of infected RIFA parasitic fungi HHYSFJ01, HHYSFJ02 and HHYSFJ05 were isolated, namely Aspergillus nomius, Purpureocillium lilacinum and Beauveria bassiana. Pathogenicity determination showed that all three strains had strong pathogenicity to RIFA, and the difference of pathogenicity among the three strains was significant. After spray treatment with 1.0×10~8 conidia/mL suspension for 10 days, the strain HHYSFJ05 was more virulent to RIFA than other isolates. Strains HHYSFJ01 and HHYSFJ02 were slightly weaker, the corrected mortality rates of RIFA were 80.00% and 74.44%, LT50were 4.99 d and 5.20 d.