| Because of its good compatibility with the environment,little selection of harmful organisms and meeting the requirements of social sustainable development,plant antimicrobial agents are becoming a hot spot in the field of fungicide research.Screening of antibacterial activity of plants is an important basis for the development of botanical fungicide.Although the work of screening with sterilization activity of plant resources have been practiced much,but,there are still many kinds of plant anti bactericidal activity is not clear in the northwest and Qinling Mountains area of China,it is necessary to expand the screening area and scope.This experiment focused on screening of Maowusu Desert Area and the south of Qinling Mountains region a total of 130 species of bactericidal activity,the main results were as follows:1.Using the growth rate method,we test the inhibite rate of mycelium of acetone extracts of 130 plants of 0.1g/m L on Colletotrichum orbiculare,Botrytis cinerea and Phytophthora capsici.The results show that the inhibite rate of Inula.salsoloides was more than 65%,the inhibition rate of Thermopsis.lanceolata,Litsea.pungen,Suaeda.dendroides,Pugilnium.cornutum,Carex siderosticta was more than 65% for at least 2 kinds of fungi.2.The acetone extracts of 63 plants of dose of 0.2g/m L were tested by the method of antibacterial ring about inhibite activity on Erwinia carotovora subsp.Carotovora Pseudomonas syringae,Bacillus subtilis.The results showed that antibacterial activity of Carex siderosticta and Potentilla glabra on three tested bacteria possessing inhibition zone about 16 mm,18mm;inhibition zone of Carex siderosticta and Inula.salsoloides on two bacteria were more than 10 mm.It is necessary to further study the antibacterial activity of Carex latifolia to bacteria.3.In the part of tissue experiment,the control effect of Inula.salsoloides,Carex siderosticta,Litsea.pungen and Lanceleaf Thermopsis on Botrytis cinerea reached more than 50%;Inula.salsoloides,Panzeria.alaschanica on cucumber anthracnose control effect was above 60%.It is worth further developing as a new botanical fungicide.Lanceleaf Thermopsis,Litsea,Carex siderosticta antibacterial activity it is necessary to further study.4.Regarding extract activity as an index of Carex siderosticta antibacterial activity the results showed that: the best extraction solvent for effective material is 95% ethanol when the solid-liquid ratio reached 1:8,and 60 ℃,extracting 8 hours,extraction rate reaching maximum of 11%;the antibacterial activity of root extract on Erwinia carotovora subsp,Pseudomonas syringae and Bacillus subtilis were higher than leaf extract,the best inhibitory effect on Pseudomonas syringae;the MIC of ethyl acetate extract of root on Pseudomonas syringae is 0.45 mg/m L.The F16 fractions separated by silica gel column chromatography produced 13 mm inhibition zone on 0.625 mg/m L for Pseudomonas syringae. |
