Abstract
An efficient micropropagation protocol was developed for Phalaenopsis amabilis cv. 'Cool Breeze' using inflorescence axis derived protocorms through in vitro culture. The thin cross sections of a young inflorescence axes of the white cultivar of Phalaenopsis amabilis hybrid were cultured on half strength Murashige and Skoog medium supplemented with N-6-benzyladenine (2.0 mg l(-1)), alpha-naphthaleneaceetic acid (0.5 mg l(-1)), 2% (w/v) sucrose, 10% (v/v) coconut water, 2 g l(-1) peptone and 1 g l(-1) activated charcoal. Each cross section produced an average of 20 protocorm-like bodies after 12 weeks. The clumps of protocorm-like bodies were cut into four pieces and subcultured on gelrite gelled half strength Murashige and Skoog medium with 2% (w/v) sucrose + 10% (v/v) coconut water + 2 g l(-1) peptone + 150 mg l(-1) L-glutamine + 1 g l(-1) activated charcoal, where each clump fragment of the protocorm-like bodies produced an average of 240 protocorm. like bodies within 8 weeks. After a further four weeks of subculture the protocorm-like bodies were found to be enlarged with leafy shoots and new protocorm-like bodies were induced from the base of the old protocorm-like bodies. Plantlet development from leafy shoots was achieved on half strength Murashige and Skoog medium supplemented with 2 g l(-1) peptone, 2% (w/v) sucrose, 10% (v/v) CW and 1 g l(-1) activated charcoal, where 100% explants were developed into plantlets with roots within 8 weeks. The addition of 50 g l(-1) banana pulp enhanced the number and length of roots. Within the first 32 weeks after initiation of culture 960 plantlets as well as a huge amount of protocorm-like bodies were achieved from a single explant section. Repeating the subculture of protocorm-like bodies on proliferation medium and culturing leafy shoots on plantlet regeneration medium could produce 2,000,000 plantlets every 32 weeks.