文心蘭無菌播種之研究

Abstract

無菌播種對文心蘭而言，是獲得實生苗之育種步驟。本研究的目的在探討培養基的成分對文心蘭種子發芽和原球體發育的影響。結果顯1/4-l/2 MS最適合文心蘭種子發芽和原球體發育，全量MS則抑制種子發芽和原球體發育。基本培養基為2g/l花寶1號添加2g/l活性碳、2g/l tryptone及0.9% 洋菜(DifcoBacto-agar)，其最適合播種的蔗糖濃度為20g/l-25g/l。種子發芽率和原球體白化率隨蔗糖濃度的增加而增加，因此認為原球體對蔗糖濃度的敏感性高於種子。此外，以2/g/l花寶1號添加20g/l蔗糖、2g/l tryptone及0.9%洋菜(Difco Bacto-agar)為基本培養基時，添加2g/l活性碳及l0ml/l椰子水有助於增加種子發芽和加速原球體的發育；單獨添加l0ml/l椰子水時，則減少種子發芽和抑制原球體的發育。椰子水同時具有有益發芽與抑制發芽的物質，而活性碳似可吸附椰子水中的抑制物質。Asymbiotic seed germination for Oncidium is used in breeding programs to produce seedling. The purpose of this research was to investigate the effect of medium composition on Oncidium seed germination and growth of protocorm. The 1/4-1/2 MS medium was most suitable for Oncidium seed germination and growth of protocorm, the full MS medium inhibited both seed germination and growth of protocorm. The optimum medium for Oncidium seed germination was 2g/l Hyponex 1 + 2 g/l activated charcoal + 2g/l tryptone + 0.9% Difco Bacto-agar with 20g/l-25g/l sucrose. Germination ratio and whiting ratio of protocorm were enhanced as the sucrose concerntration increased. Protocorm was considerably more sensitive to sucrose concentrations than seeds. 2g/l Hyponex 1 medium (containing 20g/l sucrose、2g/l tryptone and 0.9% Difco Bacto-agar) with 2g/l activated charcoal and 10ml/l coconut water enhanced both Oncidium seed germination and protocorm development. Oncidium seed germination and protocorm development were inhibited with 10ml/l coconut water. Coconut water includes both beneficial and inhibitory substances for seed germination, activated charcoal appears able to adsorb inhibitory substances from coconut water