氮素、蔗糖濃度及光強度對蝴蝶蘭種子發芽及幼苗生長之影響

Effect of Nitrogen, Sucrose Concentration and Light Intensity on Seed Germination and Seedling Growth in Phalaenopsis White Hybrid

蝴蝶蘭（白花雜交種）種子於低氮（7.55和15.10 mM）或低蔗糖濃度（10和15 g/l）下，發芽及原球體發育較佳，高氮（30.20和45.30 mM）或高蔗糖濃度（25和30 g/l）下，不僅發芽差，而且容易造成原球體之黃化或褐化。幼苗生長，則隨氮素濃度提高，根部生長漸減，以致莖葉／根比值提高，而蔗糖濃度提高對促進幼苗根部生長之程度比莖葉大，故莖葉／根比值降低，光線與蔗糖具有類似的效果，在某種範圍內並可相互取代。

Lower concentrations of nitrogen or sucrose were beneficial for seed germination and protocorm development of Phalaenopsis (white hybrid). On the contrary higher concentrations decreased the rate of germination and caused etiolation or browning of protocorm. Root growth of seedlings decreased with increasing nitrogen concentration, so the shoot/root ratio increased. Increasing the concentration of sucrose prefered to promote root growth rather than shoot growth, which decreased shoot/root ratio. The treatments of light intensity and sucrose concentration had similar effects, and could partly complement each other.