GENETIC-ANALYSIS OF RESISTANCE TO FUSARIUM-SOLANI IN SOYBEAN

Sudden death syndrome caused by highly pathogenic strains of Fusarium solani (Mart.) Appel & Wollenw. emend. Snyd. & Hans., can cause severe foliar necrosis and yield reduction in soybean [Glycine mar (L.) Merr.]. The soybean cultivar Ripley is resistant to foliar disease symptoms caused by F. solani. To determine the genetic control for F. solani resistance in Ripley, Ripley was crossed reciprocally to Spencer, a cultivar that develops severe foliar chlorosis and necrosis when infected with F. solani. Progeny from these crosses were evaluated in the greenhouse for reaction to F. solani using an infested-oat inoculation technique. Reaction to F. solani in segregating F2 and F3 generations indicated that the ability for Ripley to resist foliar disease symptoms caused by F. solani is conditioned by a single dominant nuclear gene (Rfs).