Study And Screening On Plant Extracts Against Tomato Grey Mould

120 species of plant materials were extracted with 80% ethanol and the protective and curative effects of the rough extracts were measured against Botrytis cinerea on detached leaves and in vivo. Results indicated that 5 species of the extracts showed strong protective activity and 3 species showed strong curative effect. The efficacy had no significant difference compared to chemical fungicide (diethofencard). According to the higher efficacy and lower cost, Ts-39 extract was selected and used for the further studies.The fungitoxity of Ts-39 extract was measured, the Ec50 of Ts-39 extract to Botrytis cinerea was 1.23mg/mL.The stability of Ts-39 extract was measured after being treated at different pH values and temperatures. Results showed that the efficacy of Ts-39 extract was stable at different treatments of pH values and temperatures. The efficacy was at the same level as the untreated rough extract of Ts-39, which had no significant difference compared to chemical fungicide (diethofencard).The duration of the protective efficacy of Ts-39 extract were measured by spraying rough extract at a concentration of 1% from one to seven days ahead of inoculation. The protective duration of Ts-39 was up to 4 days at least with the efficacy over 80%.Inhibitory spectrum of Ts-39 extract was tested by means of mycelium growth inhibition method. Among 11 different kinds of fungi, the rough extract of Ts-39 wasinhibitive to 6 of them with inhibitive effect over 60%. Results showed that Ts-39 extract had high inhibitory effect to Rhizoctonia solcmi up to 82.21%.The extracting efficiency of Ts-39 extract was examined by different extracting time with ultrasonic. The results showed the best extracting time of Ts-39 was 30 min.Five different chemical components were isolated from the raw material of Ts-39 by polyamide chromatography. They were baicalin , wogonoside , baicalein , neobaicalein and wogonin. The standard samples of baicalin were used for comparison by means of bioassay and HPLC. Results showed that baicalin was one of the active ingredients of Ts-39 extract.