钙磷浓度对白及种子萌发的影响

Effects of Different Concentrations of Calcium and Phosphorus on Seed Germination of Bletilla striata

【目的】探明不同浓度钙、磷对白及种子无菌萌发的影响,揭示白及对岩溶生境高钙、低磷环境的适应机制,为优化白及组培育苗技术提供参考。【方法】利用离体培养技术,分别MS培养基中加入无水氯化钙3.2g/L,磷酸二氢钾1.7g/L,配制缺钙的MS培养基,分别加入1/2倍钙、1倍钙、1.5倍钙、2倍钙、2.5倍钙、3倍钙;配制缺磷的MS培养基,分别加入1/8倍磷、1/4倍磷、1/2倍磷、1倍磷、1.5倍磷处理白及种子,观察萌发特征和生长情况。【结果】接种第5天不同培养基白及种子均开始明显吸胀,且高钙浓度对白及种子吸胀有促进作用,而低磷浓度对种子吸胀影响较小;接种第10天不同培养基种子颜色由淡黄色转变为绿色;接种第20天不同培养基中大部分种子已突破种皮,并形成子叶,甚至有的圆球茎尾部长出很细的根,在加入2倍钙、2.5倍钙、3倍钙培养基中的幼苗长出第2片子叶;1/2磷培养基中长出第2片子叶。【结论】适当增加钙浓度可促进白及种子无菌萌发后子叶生长,且随着钙浓度的增加子叶生长加快;适当减少磷浓度可促进子叶生长。

[Objective]The effects of different concentrations of calcium and phosphorus on seeds germ-free germination of Bletilla striata are explored and the adaptation mechanism of B.striata to high calcium and low phosphorus environment in karst habitat is revealed to provide a reference for optimization of B.striata tissue culture seedling technology.[Method]By using in vitro culture technology,3.2 g/L anhydrous calcium chloride and 1.7 g/L potassium dihydrogen phosphate are added to MS media separately.Calcium deficiency MS media are prepared by adding 1/2 times calcium,1 times calcium,1.5 times calcium,2 times calcium,2.5 times calcium and 3 times calcium.Phosphorous deficiency MS media are prepared by adding 1/8 times phosphorous,1/4 times phosphorous,1/2 times phosphorous,1 times phosphorous and 1.5 times phosphorous.B.striata seeds are treated with calcium deficiency MS media and phosphorous deficiency MS media to observe the germination characteristics and growth status.[Result]B.striata seeds inoculated different media on the 5th day all begin to imbibe obviously.High calcium concentration promotes imbibition of B.striata seeds,while low phosphorous concentration affects seeds imbibition slightly.The color of seeds inoculated different media on the 10th day turns green from light yellow.On the 20th day after inoculating different media,most seeds are broken through the coats and formed cotyledons,and even thin roots have been found at the end of some round bulbs.At the media of 2 times calcium,2.5 times calcium and 3 times calcium,the 2nd cotyledons of seedlings are appeared.At the media of 1/2 times phosphorous,the 2nd cotyledons of seedlings are appeared.[Conclusion]Moderately increasing calcium concentration can promote seeds germ-free germination and cotyledons growth of B.striata,and cotyledons grow faster with increase of calcium concentration.Moderately decreasing phosphorous concentration can promote cotyledons growth.