Submitted to: Society of Nematologists Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: June 23, 1998
Publication Date: N/A
Light microscopy and SEM demonstrated that the fungus V. lecanii colonized soybean roots and females and cysts of H. glycines in root tip explant cultures. To study rhizosphere colonization in soil, plastic half-cylinders (7.5 cm diameter, 10.5 cm height) were each covered with a Plexiglas sheet. These root boxes were filled with sandy soil, soybean seeds were planted, and H. glycines eggs were added. The fungus was applied to 38 boxes; 12 were untreated controls. Roots grew appressed to the Plexiglas. Four weeks after planting, the Plexiglas was removed and the roots photographed. Semi-selective agar media were pressed to soil and roots in each box and incubated. Fungus colonies on the media were photographed. The experiment was repeated once. Image processing analysis of the spatial distribution of V. lecanii demonstrated random distribution in the soil and rhizosphere, and low numbers of colony-forming units. Poor rhizosphere colonization in the competitive environment of natural soil may account for some of the variable biocontrol results observed with this fungus in microplot studies.