REGENERATION OF LATE LEAF SPOT-RESISTANT GROUNDNUT PLANTS FROM CERCOSPORIDIUM-PERSONATUM CULTURE FILTRATE-TREATED CALLUS

Cotyledon callus cultures of groundnut (Arachis hypogaea L.) derived f rom tikka late leaf spot disease-susceptible and resistant genotypes w ere exposed to various concentrations of fungal culture filtrate (FCF) of Cercosporidium personatum, the causal fungal agent of tikka late l eaf spot disease. Fresh weight and cell viability of calli were determ ined after exposure to various concentrations of FCF. Sensitive calli have failed to increase in fresh weight and lost viability after expos ure to media containing the FCF whereas insensitive calli retained gro wth and maintained viability similar to controls, viz, calli not expos ed to FCF, Insensitive calli were selected by culturing on growth medi um containing various concentrations of the FCF. Resistant calli obtai ned by selection survived three subcultures under the same conditions and were used for plantlet regeneration, Regenerated plants when trans ferred to soil-sand mixture in plastic cups and subsequently shifted t o field conditions, set few viable seeds. Plants of R-2 generation exh ibited enhanced resistance to tikka late leaf spot disease.