一株寄生曲霉Q527对黄野螟的感染作用及生物学特性

Infection Effect of A Strain of Aspergillus sp. Q527 on Heortiavites soides and Its Biological Characteristics

【目的】为了获取更多控虫真菌资源,对从野外的黄野螟死亡幼虫分离得到的一株曲霉菌进行致病性测定和培养,为培养高致病性生防真菌提供理论依据。【方法】以寄生曲霉Q527为试验材料,采用浸渍法测定了寄生曲霉Q527对黄野螟的感染作用,利用菌丝生长速率法和产孢量法对其培养条件及产孢特性进行初步研究。【结果】寄生曲霉Q527对黄野螟幼虫具有良好的感染作用,浸渍法接种7 d后校正感染率达83.3%;寄生曲霉Q527生长最适培养基为PDA培养基,在此培养基培养7 d平均菌落为78.18 mm;pH为8适应生长和产孢分别为78.12 mm和2.61×10~9个;其不耐高温,在65℃停止生长和孢子萌发;乳糖作为碳源有效促进寄生曲霉Q527菌丝生长,大小为37.97 mm;可溶性淀粉作为碳源有效促进寄生曲霉Q527产孢,产孢量为2.03×10~9个;蛋白胨作为氮源有效促进寄生曲霉Q527菌丝生长和产孢,分别为51.06 mm和2.96×10~9个;在黑暗状态中生长最好,分别为78.17 mm和2.63×10~9个。【结论】寄生曲霉Q527对黄野螟具有较强的致死性且具有生长速度快和适应性强等生物学特性,在黄野螟的生物防治中有潜在的应用价值。

[Objective]In order to obtain more resources of insect-controlling fungi, the pathogenicity of an Aspergillus strain isolated from the dead larvae of Heortiavites soides in the field was determined and cultured to provide a theoretical basis for the cultivation of highly pathogenic biocontrol fungi.[Method]Aspergillus sp. Q527 was used as experimental material to determine the infection effect of Aspergillus sp. Q527 on H. soides by impregnation method. The culture conditions and sporulation characteristics of Aspergillus sp. Q527 were studied by mycelium growth rate method and sporulation quantity method.[Result]The results showed that the Aspergillus sp. Q527 had a good infection effect on the larvae of H. soides. The corrected infection rate was 83.3% after inoculation for 7 days, and the optimal medium for the growth of Aspergillus sp. Q527 was PDA medium. The average colony cultured on PDA medium was 78.18 mm;the pH8 was suitable for growth and sporulation, with the size of 78.12 mm and sporulation amount of 2.61×10~9;It could not resist high temperature and stopped growing and sporing germination at 65 C. Lactose, as a carbon source, effectively promoted the growth of Aspergillus sp. Q527 mycelium, with the size of 37.97 mm;soluble starch, as a carbon source, effectively promoted Aspergillus sp. Q527 sporulation, with the sporulation amount of 2.03×10~9;peptone, as a nitrogen source, effectively promoted the growth and sporulation of Aspergillus sp. Q527 mycelium, with the size of 51.06 mm and the sporulation amount of 2.96×10~9 respectively;the best growth condition was in dark state with the colony of 78.17 mm and the sporulation amount of 2.63×10~9.[Conclusion]Aspergillus nomius Q527 is lethal, fast-growing and adaptable to H. soides, and has potential application value in biological control of H. soides.