FACTORS AFFECTING PROTOPLAST CULTURE OF CUCUMIS-MELO GREEN DELICA

Hypocotyls, cotyledons and etiolated half-expanded leaves of Cucumis m elo 'Green Delica' were used as explants for protoplast isolation and culture. Protoplasts isolated from cotyledons and etiolated half-expan ded leaves cultured in Durand, Potrykus and Donn (DPD) medium suppleme nted with 0.9 mu M benzylaminopurine (BAP), 3.6 mu M 2,4-dichloropheno xyacetic acid (2,4-D) and 1% sucrose, using the agarose bead culture m ethod, were able to form cell walls and subsequently go through cell d ivision. Pretreatment of half-expanded leaf explants in the dark for 1 4 d provided the best material for protoplast isolation and cell divis ion. Approximately one third of protoplasts from etiolated half expand ed leaves formed microcolonies. For hypocotyl protoplasts, none of the treatments used were suitable to induce cell division. There was no s ignificant difference between sucrose, glucose, and sucrose plus gluco se, in culture media on the plating efficiency of leaf protoplasts of C. melo 'Green Delica'; however, bigger colonies were formed in media supplemented with 1% sucrose. No shoot or whole plant regeneration was achieved. However, the methods reported here provide further informat ion on C. melo protoplast culture. (C) 1998 Annals of Botany Company.