Study On Inhibitory Effects Of Chinese Herbal Medicine Extracts On Pathogenic Fungi In Postharvest Tomato

The experiment use plate growth rate method the in-vitro inhibitory effects of 16 kinds of Chinese herbal medicine extracts against pathogenic fungi in postharvest tomato. The experiment use dilution methods to test the 50% effect concentration (EC50);The minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) of the effective Chinese herbal medicine extracts were preliminarily determined;Then, the fresh tomato was used as material inoculated with postharvest pathogenic fungi for studying the controlling effects of plant extracts screened previously effects of inhibitory capacity on the lesion development;The ultrastructure of Boteryeis cinerea and Alternaria alternate treated by Chinese herbal medicine extract was observed through SEM (scanning electron microscope) and TEM (transmission electron microscope);The activities of PAL, PPO, POD induced by inoculation with Chinese herbal medicine extract were studied in tomatoes.The main conclusions are as follow:(1)"In vitro"test, 16 kinds of Chinese herbal medicine extract had different inhibitory effects against the occurring and spreading of corresponding pathogenic fungi, Chinese herbs No.2 and No.10 showed higher inhibiting rates than others, the rates of the concentration of 10mg/mL is 66.61%,62.75% for Botrytis cinerea;87.05%,77.57% for Alternaria alternata respectively; The 50% effect concentration (EC50) of Chinese herbs No.2 for Botrytis cinerea and Alternaria alternata was 5.952 mg/mL,2.736 mg/mL;The 50% effect concentration (EC50) of Chinese herbs No.10 for Botrytis cinerea and Alternaria alternata was 8.742 mg/mL, 2.925 mg/mL.The their MIC on Botrytis cinerea were 12.5 mg/mL, 25 mg/mL, meanwhile their MFC were 25 mg/mL, 50 mg/mL, respectively; their MIC on Alternaria alternata were 6.25 mg/mL, 12.5 mg/mL, were 12.5 mg/mL and 25 mg/mL respectively.(2)"In vivo"test, two Chinese herbal medicines extracts showed different inhibitory effects against the occuring and spreading of corresponding pathogenic fungi on tomato. No.2 herbs had the highes inhibiting rates.(3) The SEM and TEM observation showed that No.2 herbs at concentration of MIC and MFC could also disrupt the shape and structure of Boteryeis cinerea and Alternaria alternate.(4) Activities of PAL, PPO, POD induced by inoculation with No.2 herbs at 100 mg/mL were studied in postharvest tomatoes. The activities of PAL, PPO and POD could be induced by infection with herbs or the mixtion of herbs and Boteryeis cinerea.