Regeneration of late leaf spot-resistant groundnut plants from Cercosporidium personatum culture filtrate-treated callus

Abstract

Cotyledon callus cultures of groundnut (Arachis hypogaea L.) derived from tikka late leaf spot disease-susceptible and resistant genotypes were exposed to various concentrations of fungal culture filtrate (FCF) of Cercosporidium personatum, the causal fungal agent of tikka late leaf spot disease. Fresh weight and cell viability of calli were determined after exposure to various concentrations of FCF. Sensitive calli have failed to increase in fresh weight 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 survived three subcultures under the same conditions and were used for plantlet regeneration, Regenerated plants when transferred to soil-sand mixture in plastic cups and subsequently shifted to field conditions, set few viable seeds. Plants of R-2 generation exhibited enhanced resistance to tikka late leaf spot disease.