Screening Antifungal Plants And Study On Antifungal Activity Of Pterocarya Steonoptera

There are a lot of plant resources in Liaoning, so it is an ideal place for us to search new fungicides from plants. The research was based on screening antifungal plants in Liaoning. The fungistatis of 40 plants 95% ethanol extracts were systematically tested with Fusarium oxysporiumf.sp.melonis,Curvularia lunata Boed.,Erwinia carotovora, and we found Pterocarya steonoptera had higher antifungal activity. So it was studied further. The rusults were as following:1. By testing the vitro activity of 40 plant samples 95% ethanol extracts, the concentration is 0.05g/ml, against 2 pathogenic fungi, we found that the extracts inhibition of Pterocarya steonoptera was more than 75%, and was better than others.Several organic solvent extracts of Pterocarya steonoptera showed that the acetone extracts inhibition was more than 80%, the inhibition zones they formed were bigger.,which is 35.5mm,39.2mm respectively.2.On the base of the single factor experiments, the ratio of raw material to acetone,extraction temperature,extraction time,extraction times were selected as four factors to design the orthogonal test and the best extraction condition was obtained. The main results followed as bellow: the ratio of raw material to acetone is 1:30,extraction temperature is 60℃,extraction time is 24h,extraction times is forth.3. Fusarium oxysporiumf.sp.melonis,Curvularia lunata Boed were selected as sensitive bacteria to the study,and the rusults showed that the MIC is 2.5mg/mL,which is diluteed 400 times, the MBC is 5 mg/mL; using the methods such as growth spreading methods,rate of germination,dry weight of hyph aassay found that the inhibition activity was obvious. The inhibition was stable in acid conditon, and temperature has small affect on it.4. The emusifiable solution was made of tween-80 and extracts of Fusarium oxysporiumf.sp.melonis . When it was diluted 200 times(5mg/ml), its inhibition effect was similar with Carbendazim WP diluted 1000 times and mancozeb diluted 1200 times.Using growth spreading methods, we found that the inhibitory activity of Fusarium oxysporiumf.sp.melonis extracts was more effective than Carbendazim WP, less than mancozeb. tomato seed germination test indicated that Fusarium oxysporiumf.sp.melonis extraction emulsion could promote tomato seed germination and growth at 2.5mg/ml～1mg/ml mg/ml,and it also had some activity on PAL and PPO.