THE EFFECT OF POLLINATION ON FRUIT FORMATION AND IN VITRO CULTURE OF CYPRIPEDIUM JAPONICUM THUNB. SEEDS

摘要

Cypripedium japonicum is a globally threatened species and is one of the most endangered species in Korea. In this study we investigated the artificial pollination for fruit bearing and in vitro germination of immature and mature seeds of the species.In its natural habitat in Deogyu Mountain, a national park in Korea, fruit capsule formation was not observed due to pollination failure. Artificial pollination resulted in 100% of fruit capsule formation regardless of whether it was achieved by self- or cross-pollination. The in vitro germination of immature and mature seeds was studied. Immature seeds at 50 days after pollination were cultured on six media containing various cytokinins. The highest germination rate of the seeds was 38.5% on P6668 medium that contained 1.0 mg l~(-1) BA. In the fully matured seeds, the pretreatment with 1% NaOCl for 30 min was required to initiate the germination of the seeds, but this germination was five-fold lower (5.8%) than that of the immature seeds. The germinated seeds developed to the protocorm stage, but further growth to plantlet stage was not achieved. This result indicates that further study regarding the post-germination growth of these embryos is necessary.