Studies On Insecticidical And Fungicidical Components Of Endophytic Fungus In Celastrus Angulatus

Plant endophytic fungus is a kind of fungus which spends all or most life cycles in plant posts, and does not make any diseased symptom. The primary studies on insecticidical and fungicidical components of endophytic fungus in Celastrus angulatus have been carried out from September, 2000 to June, 2002.The results are as follows:Taking PDA and Czapek as separating culture medium, 39 strains of endophytic fungus were separated from the bark, phloem and xylem of the root and twig of Celastrus angulatus.The activities of stomach and contact poison of the fermentation extracts of 39 strains were tested against the 3th instar larvae ofMythimna separata at the concentration of 500 u g/ml. The results showed that the acetone extract of IB strain mycelium exhibited poisonous activity, and had a mortality of 85.3% against the tested larvae.By means of mycelium growth rate, the acetone extracts of fermentation products of 39 strain were tested against Botrytis cintrea,Gibberella zeae, Phytophthora capsic, Glomerella cingulata, Bipolaris maydis, Alternaria alternata at the concentration of 500 u g/ml. The results showed that the acetone extract of 1L, 2B and 5J strains fermentation products had a certain degree fungicidical activity. The results of pot test indicated that the acetone extracts of 1L 2B and 5J exhibited more than 60% of both protective efficacy and therapeutic efficacy against Blumeria graminis disease at the concentration of 500 u g/ml. The acetone extracts of 1L and 2B exhibited more than 50% of both protective efficacy and therapeutic efficacy against Pseudoperonospora cubensis disease at the concentration of 500 u g/ml.An insecticidal component, 1B-4 was isolated from the acetone extract of the mycelium of IB strain by bioassay-guided. The molecule structure of 1B-4 was determined by IR and NMR as a kind of fatty acid. 1B-4 might be a mixture of two isomers.Three fungicidal components, 1L-3, 1L-6 and 1L-8 were isolated from the acetone extract of the mycelium of 1L strain by bioassay-guided opencolumn chromatography and Pre-HPLC. The inhibiting rate of 1L-6 was more than 92.7% against the mycelium growth of Leucaninia separata.II, 2B and 51 were identified as Rhynchosporium sp., Fusarium prolifenafum and Pestalotiopsis SP respectively.