Regeneration of stem and pod rot resistant groundnut plants from Sclerotium roltsii Sacco culture filtrate treated callus

Mature embryo derived callus' cultures of groundnut (Arachis hypogaea L.) from stem and pod rot susceptible genotypes were exposed to various concentrations of fungal culture filtrate (FCF) of Sclerotium rolfsii Saac., the predominant causal agent of stem and pod rot disease. Cell survivability and viability of calli was determined after exposure to various concentrations of FCF. Sensitive calli failed to survive and lost viability after exposure to media containing the FCF whereas insensitive calli retained growth and maintained viability similar to controls, viz., calli not exposed to FCF. Insensitive calli were selected by culturing on growth medium containing various concentrations of the FCF. Resistant calli obtained by selection pressure survived two subcultures under the same conditions and were used for plant regeneration. Regenerated plants when transferred to soil-sand mixture in plastic pots and subsequently shifted to field conditions, set viable seeds. Plants of Ra generation exhibited enhanced resistance to pod and stem rot disease.