| It is well known that Botrytis cinerea is one of the most geographically widespread plantpathogen, which can produce bioactive compounds when it is cultured under a certaincondition. In order to exploit these compounds and develop environment acceptable pesticide,Botrytis cinerea has been used in this research. BC4 isolate of Botrytis cinerea was chosenfrom 11 isolates collected from 7 regions in China. The insecticidal, fungicidal and herbicidalactivity of fungus-free culture filtrate of BC4 isolate were bioassayed. Then the activemetabolites were isolated from the culture filtrate and identified by IR, NMR, LC-MS andGC-MS. The effects of light and concentration on the activity of culture filtrate were alsostudied. In addition, the better condition to produce active compounds has been observed.This paper is a report of all results. 1. It is indicated by the results that the BC4 is one of the high-activity isolate in the 11tested isolates, and weed Amaranthus retroflerus L. is the most sensitive plant in the 4 plantsused. The better condition to produce active metabolites from BC4 is to culture it in Friesmedium ofpH3-4 at 25℃ under dark and static condition. 2. Bioassay results show that BC4 isolate and its fungus-free culture filtrate both have asignificant fungitatic activityto Rizoctonia cerealis, Cochlioblus sativus and Gibberella zeae,the inhibition percent to three fungi was above 56%. Culture filtrate also has an antibacterialproperty to Erwinia carotovora and Clavibacter michiganensis ssp.sepedonicus. Theherbicidal effect of culture filtrate is remarkable, all kinds of weeds tested were extremelyrestrained by the culture filtrate in seed germination period. To seedling stage, theAmaranthus retroflerus L. and other dicotyledonous weeds were strongly hurt when theculture filtrate was sprayed on them, but wheat and corn tesed has not been affected whensame amount of it used. Thus, the culture filtrate may contain some herbicidal componentsand fungitatic components. 3. Safety of the culture filtrate to wheat, corn and cotton has been bioassayed. The resultshows that the 20 times-diluted culture filtrate may also restrain seed germination of wheatand corn. However, It has no effect to seedling, and even 12 times concentrated culture filtratehas no any reduction on their yields. Thus, the culture filtrate may be used directly (or use itseffective components) as a herbicide to inhibit the dicotyledonous weeds in wheat and cornfields, and also be used as a fungicide to protect wheat from Rizoctonia cerealis, Cochlioblussativus and Gibberella zeae ect. 4. 4 active metabolites have been isolated from the culture filtrate of BC4 by TLC, LCand HPLC. Of the four compounds, one shows a strong killing activity to seedling ofAmaranthus retroflerus L., and the other three display a strong inhibition to seed germination. 5. The three inhibitive compounds have been identified as s - (+)-abscisic acid(commonname is ABA), s-(+)-abscisyl-?-D-glucose ester and s-(+)-abscisyl-?-D-glucoside. The lattertwo compounds are first reported being isolated from Botrytis cinerea. 6. Hydrolysis test of s - (+)-abscise-?-D-glucose ester suggested that s -(+)-abscisyl-?-D-glucose ester has been hydrolyzed under HPLC condition during theisolation. The light-treating test of s - (+)-abscisyl-?-D-glucoside and analysis of itshydrolyzed products suggested that s - (+)-abscisyl-?-D-glucoside may be rearranged into s -(+)-abscise-?-D-glucose ester under UV beam from HPLC detector. Thus it can be inferredthat s - (+)-abscisic acid in the metabolites is existed at the beginning in a form of s -(+)-abscisyl-?-D-glucoside. When the metabolite was exposed under daylight or lamplight,the latter one converts into s - (+)-abscisyl-?-D-glucose ester, which then hydrolyzed andproduced s - (+)-abscisic acid and its inactive isomer. So the metabolite is a mixture of thesecomponents. 7. Bioactivity and color changeability of light-treated culture filtra...
|
PDF Full Text Request