A Preliminary Study On Screening Toadstools With Insecticidal Activity And Their Mycelia Culture In Guangxi

This paper was a preliminary study on screening toadstools with insecticidal activity and their mycelia culture in Guangxi.Twenty-eight species of toadstools were collected from different regions of Guangxi.They were under 13 families.The family with most toadstool was Amanitaceae,5 species;the second one was Tricholomataceae,4 species;and the Agaricacea, Coprinaceae and Boletaceae were 3 species.The crude of the 28 toadstools were extracted from fresh fruitbodies and cultured mixture using distilled water,ethanol and petroleum ether as menstruum respectively.Then the crude extracts were used to detect whether they had insecticidal activity against Prodeniaa litura and Pultella xylostella.The results showed that during 3 days,the crude extracts from 24 species of toadstools had insecticidal activity against Prodeniaa litura,and from 23 species of toadstools had insecticidal activity against Pultella xylostella.The crude extracts with distilled water about Amanita solitaria,A.spissacea and A.sychnopyramis were toxin to Prodeniaa litura and Pultella xylostella,which the corrected mortalities were 100%.The insecticidal activity of the toadstools was first reported except Sclerderma flavidum,Gymnopilus spectabilis and A.sychnopyramis.The crude extracts from solid culture mycelia of Coprinus atramentarius and Gymnopilus aeraginosus were toxic to Prodeniaa litura.And the crude extracts from liquid culture mycelia of 4 species of toadstools such as Amanita vaginata and A.brunnescens were toxic to Prodeniaa litura and Pultella xylostella.Isolation and artificial culture of 28 species of toadstools were conducted. The results showed that only 10 species of toadstools such as A.brunnescens,A.vaginata,Psilocybe coprophila could be artificial cultured.The isolation and artificial culture of A.brunnescens,A.vaginata and G.aeraginosus were first reported.The optimal artificial culture conditions of 4 toadstool species which not only had insecticidal activity but also could be isolated as below respectively:The optimal solid media for C.atramentarius mycelia was PDA plus extraction from cattle manure;the optimal carbon and nitrogen sources were Lactose and peptone;the optimal temperature for the mycelium growth was 28～32℃;and the optimal pH was about 7.0.The optimal solid media for G. aeraginosus mycelia was PDA plus extraction from tree leaves;the optimal carbon and nitrogen sources were glucose and casein;the optimal temperature for the mycelia growth was 30℃;and the optimal pH was about 6.0.The optimal solid media for A.brunnescens and A.vaginata were PDM;the optimal carbon sources were maltose and mannite;the optimal nitrogen sources were yeast extract and casein respectively;the optimal temperature for the mycelia growth was 30℃and 28℃,the optimal pH was 5.0 and 6.0.The optimal liquid media for mycelia growth of C.atramentarius were 2.0%glucose,0.5%defatted soybean powder,0.3%K₂HPO₄,0.3% MgSO4₄·5H₂O and 10%cattle manure.The optimal growth conditions for mycelia of C.atramentarius were:culture temperature 28℃,pH 7.0,90 ml substrata in 250 ml shake flask and inoculating amount 10%.The results of liquid culture provide scientific basis for the mass culture of the toadstools.