Entomopathogenic nematodes (EPNs) have been the subject of more and more research and commercial interest as one important biological control agent of soil pests over the world due to a high demand for ecologically sustainable agriculture. The advantages for using EPNs include their wide range of insect hosts, the fact that they are non-toxic and non-polluting to the environment and humans, are mass produced easily and have the ability to rapidly kill insects. Although the field application of EPNs against pests obtained certain progress, the unstable control effects in the field caused by multiple environmental factors inhibit EPN wide utilization. Therefore, it is very important to explore the interactions among EPNs, insects, and host habitat plant roots and how soil ecological environment factors affect biocontrol efficacy. Currently, most studies focus on the interaction between EPNs and their host insects and little is known about interaction between EPNs and their host-habitat plant roots due to invisible three-dimensional soil environment and dynamic movement in the soil.
The Agricultural Pest Control Group led by research professor Congli Wang utilized one transparent, non-toxic Pluronic gel which is liquid under 15oC and semi-solid above 15oC. The gel simulating three-dimensional soil environment was successfully applied to study the interaction between plant pathogenic nematodes and their host plant roots, but not for the interaction between EPNs and their host-habitat plant. This group first reported that the Pluronic gel is a useful medium to study the interaction between EPNs and host-habitat plant roots and to be used to observe direct attraction of nematode to plants under the dissecting microscope. They found that 1) mechanically damaged roots greatly improve seeking ability of EPNs; 2) host habitat root exudates plays an important role in directing EPN localization; 3) Storage duration and species/strains of EPNs influence nematode response to roots. The research further explained why EPN could control chive root gnat.
The Pluronic gel system will not only broaden our vision of plant defense schemes but it will also facilitate the new understanding of chemicals released by roots to provide more efficient control for certain EPN-plant combination. The research achievement was published in the journal of ‘Biological Control’.
The paper: Li Chunjie, Wang Yi, Hu Yanfeng, Hua Cui, Wang Congli*. Three dimensional study of wounded plant roots recruiting entomopathogenic nematodes with Pluronic gel as a medium. Biological Control, 2015, 89: 68-74.
The link : http://www.sciencedirect.com/science/article/pii/S1049964415001115
