PRODUCTION OF HIGH-FREQUENCY EMBRYOGENIC CALLI FROM INTEGUMENTS OF IMMATURE SEEDS OF CARICA-PAPAYA, L

Tissue culture conditions that enable production in Carica papaya L. o f high frequency embryogenic calli on the internal integuments of imma ture seeds are defined: The explants have to be removed three or four months after anthesis and cultured on the three monthly successive med ia: M1-1 (2,4-D 9 mu M), M2 (2,4-D 0.09 mu M + KIN 1 mu M), M3 (M2 + A BA 0.5 mu M). A histocytological study during culture proved that fria ble calli capable of producing embryos were of maternal origin. This p rocedure thus permits the cloning of adult plants.