典型草原常见牧草春季萌动期可溶性糖及内源激素动态研究

在春季萌动期，分别对典型草原几种常见禾本科牧草老芒麦、披碱草、羊草、赖草和克氏针茅的幼芽和地下根系可溶性糖含量及内源激素动态变化规律进行研究.结果表明,高含量的GA和较低含量的ABA是根茎类禾草羊草和赖草春季萌动早的重要调控因子，而根系丰富的可溶性糖为根茎类禾草的萌动生长提供了物质基础；玉米素核苷动态变化趋势与根系可溶性糖含量动态相似，萌动初期呈下降趋势，4月底达到最低值，此后又逐渐上升；而内源激素IAA和GA的含量与牧草幼芽可溶性糖含量的变化趋势一致，均呈逐渐上升趋势；根茎类禾草羊草和赖草与须根系禾草老芒麦和披碱草之间幼芽的GA和ABA水平以及根系可溶性糖含量差异明显.

Dynamics of soluble sugar and endogenous hormone contents in several steppe grass species during their germination period in spring

The study on the dynamics of soluble sugar and endogenous hormone contents in steppe grass species Elymus sibiricus, E. rectisetus, Leymus chinensis, L. racemosu and Stipa krylovii during their germination period in spring showed that high content GA and low content ABA played an important role for L. chinensis and L. racemosus germination, and the abundant soluble sugar storage in root made the rhizome grasses germinate earlier and grow stronger. The dynamics of ribosylzeatin was similar with that of solubie sugar in root, i. e., declined in early germination period, reached the lowest by the end of April, and ascended then, while the IAA and GA contents had a similar variation trend with the soluble sugar content in bud, i. e., all ascended gradually. There was a significant difference in the contents of GA, ABA and soluble sugar between rhizome grasses L. chinensis and L . race,2osus and fibrous-root grasses E. sibiricus and E. rectisetus .