| The in vitro germination of Cypripedium candidum Muhl. ex Willd., C. calceolus L. var. parviflorum (Salisb.) Fern. and C. reginae Walt. was investigated.;To improve in vitro germination, three media and different times of seed collection were compared. Seed pods were collected at regular intervals after pollination and seed inoculated onto three media, Harvais, Van Waes and Debergh, and modified Norstog. Germination was then assessed at 4-week intervals for 20 weeks. Except for C. candidum in 1989, where germination peaked for seed collected 6 weeks after pollination, seed collected eight weeks after pollination gave the highest germination. There were differences among media, but their effects on germination were not consistent and depended on the year, date of collection and the species. Subsequent development of protocorms was superior in all cases on modified Norstog medium. The effect of cold treatment of seed on the germination of C. candidum was investigated.;Subsequent experiments were performed using modified Norstog medium and seed collected eight weeks after pollination to investigate the requirement for cytokinins and the cytokinin preference for in vitro germination and protocorm development of C. candidum. Two of the three cytokinins tested, BA and 2iP, increased germination of concentrations of up to 0.8 mg L... |
