DETERMINATION OF CALLUS GROWTH CURVE IN CONILON COFFEE

Resumo

Callus culture has shown a great potential for large-scale multiplication of superior genotypes in a short period of time. The objective of this work was to establish a methodology to induce callus formation in leaf fragments of Coffea canephora Conilon cultivar, to determine the growth curve and to analyze the development of the calli. The growth curve allows to determine the suitable time to subculture the calli in a new medium. The explants were inoculated in 50% MS medium with 10 mg.L-1 thiamine, 1 mg.L-1 pyridoxine, 1 mg.L-1 nicotinic acid, 1 mg.L-1 glycine, inositol 100 mg.L-1, hydrolysed casein 100 mg.L-1 and 400 mg.L-1 malt extract, 20 g.L-1 sucrose, 8 g.L-1 agar, supplemented with IBA (10 µM), 2,4-D (20 µM) and 2iP (10 µM). To determine the growth curve, the calli were weighted up to the 60th day of culture. The callus growth curve presented sigmoidal shape, with five distinct phases. The subculture must be done on the 53th day of culture, aiming at the plant regeneration.