温度和干旱胁迫对3种牧草种子萌发的影响

Effect of temperature and drought stress on seed germination of three forage species

对扭黄茅Heteropogon contortus、鸭茅Dactylis glomerata、高羊茅Festuca arundinacea3种牧草，进行了3个不同温度、4个不同干旱胁迫强度的种子萌发试验，分别测定了牧草品种的发芽率、发芽势和萌发指数，并进行了统计分析。研究结果表明：在自然条件下．扭黄茅种子萌发是在常温条件下完成的。不同温度和聚乙二醇胁迫强度处理影响下，扭黄茅种子均先于鸭茅和高羊茅种子萌发2～3d．扭黄茅萌发指数均高于鸭茅和高羊茅。低胁迫干旱强度有助于扭黄茅种子萌发。当干旱胁迫强度超过一定程度（-3Pa）时不利于种子萌发。扭黄茅对干热河谷生态条件的适应性主要由种子萌发后的植株生长适应性决定的。

The seeds of Heteropogon contortus, Dactylis glomerata and Festuca arundinacea were used for seed germination tests under temperature and drought stress. Seed germination rate, germination vigor and germination index of 3 forage species treated with 3 different temperatures and 4 different drought stress levels were measured. The results showed the seeds of H. contortus could germinate under the room temperature in natural environment. The seedling emergence of H. contortus was 2 to 3 days earlier than D. glomerata and F. arundinacea under different temperatures and PEG. The germination index of H. contortus was higher than D. glomerata and F. arundinacea. Low drought stress was helpful for the seed germination of H. contortus, but unfavorable when drought stress was over --3 Pa. The adaptability of H. contortus to dry and hot valley mainly depended on the adaptability after germination.