碳源及氮素濃度對報歲蘭根莖生長及分化之影響

Effects of Carbon Source and Nitrogen Concentration on Growth and Differentiation of Rhizomes in Cymbidium sinense in vitro

本研究探討1／2MS基本培養基中，碳源及氮素濃度之不同對白花報歲蘭及‘金華山’報歲蘭根莖生長及芽體分化之影響。其目的在改善報歲蘭組織培養苗生長緩慢及芽體分化時間不一致等問題。比較培養基中使用87.6 mM蔗糖、175.2 mM葡萄糖、175.2 mM果糖及87.6 mM葡萄糖加87.6 mM果糖四種碳源，果糖處理組兩品系根莖之周徑及鮮重數值皆最低，但不同碳源對根莖生長之影響並未達統計上之顯著差異。報歲蘭適合之氮素濃度範圍依品系及分化階段不同而異；根莖生長所需氮素濃度較芽體分化所需者為高。白花報歲蘭於50.6 mM氮素濃度而‘金華山’報歲蘭於30.0 mM氮素濃度下，根莖長度、周徑及鮮重累積最高。兩品系皆以最低氮素濃度（14.6 mM）處理組之芽體及根部鮮重累積最高。 In order to find ways to improve the rate of growth and uniformity of bud differentiation of Cymbidium in the in vitro propagation, we tested different carbon sources and nitrogen concentrations in the media for propagating Cym. sinense var. albo-jucundissimum and Cym. sinense 'Chin Hwa Shan' rhizomes. Four carbon sources, namely: 87.6 mM sucrose, 175.2 mM glucose, 175.2 mM fructose, and 87.6 mM glucose plus 88 mM fructose were compared. The medium with fructose as the sole carbon source resulted in the numerically lowest diameter and fresh weight of rhizomes. However, the differences in rhizome growth made by the 4 carbon sources were not statistically significant. The optimal nitrogen concentration for Cym. sinense depended on the cultivar and developmental stages of the plants. Nitrogen concentrations of 50.6 mM and of 30.0 mM resulted in fastest rhizome growth in Cym. sinense var. albo-jucundissimum and Cym. sinense 'Chin Hwa Shan', respectively; while the highest fresh weights of shoots and roots were achieved by 14.6 mM nitrogen in both cultivars.