Role of the isoflavonoid coumestrol in the constitutive antixenosic properties of Davis soybeans against an oligophagous insect, the Mexico bean beetle.

Reference Report for IND20354153

Title:	Role of the isoflavonoid coumestrol in the constitutive antixenosic properties of Davis soybeans against an oligophagous insect, the Mexico bean beetle.
Authors:	Burden, B.J., Norris, D.M.
Source:	J. Chem. Ecol. 1992, 18(7):1069-1081
Abstract:	The antixenosic properties of the isoflavonoid, coumestrol, were tested in dual-choice leaf disk bioassays with the Mexican bean beetle (Epilachna varivestis Mulsant). E. varivestis preferred the methanol-treated (solvent control) disk when the coumestrol concentration was 1.8 or 0.9 micrograms/leaf disk. No preference was observed between the coumestrol-treated and the solvent-control disks when the coumestrol concentration was higher, at 3.6, or lower, at 0.45 micrograms/leaf disk. Coumestrol alone clearly is not responsible for the significant constitutive antixenosic properties of Davis soybeans, Glycine max (L.) Merrill, because the amount of coumestrol in these plants is significantly less than the minimum concentration which was antixenosic in this study. However, it might contribute to a constitutive antixenosis in Davis involving a profile of allelochemicals. A computer-aided densitometer, adapted to measure the leaf disk area, increased the resolution of the leaf area 250 (x)-fold as compared to the standard LI-COR leaf area meter.

Funded by the USDA-ARS. Developed by the USDA-ARS SoyBase and Legume Clade Database group at the Iowa State University, Ames, IA

U.S. Public Domain