ISOLATION AND IDENTIFICATION OF NOVEL ALLELOCHEMICALS AND UTILIZATION OF ALLELOPATHIC COVER PLANTS FOR SUSTAINABLE AGRICULTURE

We are now operating a National Project, entitled “Screening of innovative allelochemicals and their utilization” from 2008 to 2012. We have screened about 4000 plants all around the world, mainly from Japan and Asian countries, and evaluated these by specific bioassays for allelopathy, including “Plant Box Method”, “Sandwich Method”, “Dish-pack Method”, and “Rhizosphere Soil Method”. Our final target is to isolate novel bioactive natural chemicals from allelochemicals. Strategies for screening new allelochemicals are based on “Total Activity Method”, carefully calculating the concentration of allelochemicals in plants. We have already isolated cis-cinnamic acid derivatives as potent allelochemicals, and obtained a patent and now are performing organic synthesis of derivatives to increase activity. Mode of action of new allelochemicals are evaluated by DNA microarray technique using Arabidopsis as the receiver plant. Volatile allelochemicals are another target of our screen for allelochemicals. Final goal of this study is the utilization of allelochemicals as new agrochemicals. Another goal of our study is to use allelopathic plants as ground covers for agricultural and natural settings. Some promising domestic and alien plants with allelopathic activity were screened, and field tested to demonstrate their potential; utilization of these new ground cover plants will be discussed.