不同温度下中国沙棘种子的萌发策略

摘要

To search seed germination strategy of Hippophae rhamnoides L subsp sinensis Rousi, seed germination responses at different temperature are examined here. The results show the germination percentage at 15 ℃ , 20℃ and 25℃ are more than 88% and significantly higher than the germination percentage at 30 ℃(73. 33%) and 35℃ (4. 67%). At the end of germination, the length of radicle and hypocotyls are also significantly longer than that at higher temperature(30℃ ,35℃). The germination percentage, germination energy and the length of radicle and hypocotyls are inhibited under the higher temperature. In addition, seeds of H rhamnoides subsp sinensis begin to germinate within 3~4 days and last for 7～15 days under each temperature treatment. These characteristics indicate that H rhamnoides subsp sinensis is different from the other plants of Hippophae from Qinghai-Tibet plateau of china in germination strategy.%分布于青藏高原的沙棘属植物具有与其环境相适应的种子萌发对策,为探求主要分布于我国青藏高原边缘至华北等海拔较低地区的中国沙棘(Hippophae rhamnoides L subsp sinensis Rousi)的萌发对策,本文对中国沙棘在不同温度下种子的萌发特征进行了研究.结果表明:中国沙棘种子在15～30℃范围内均有较高的发芽率,其中在温度为15、20和25℃时发芽率这88％以上,显著高于30℃(73.33％)和35℃(4.67％)下的发芽率,萌发结束时胚根及下胚轴长度也显著大于较高温度(30,35℃)下的长度,过高温度对其发芽率和发芽势及其胚根和下胚轴长都产生抑制作用.此外,中国沙棘种子在各温度处理下,3～4 d内开始萌发,7～15 d完成萌发过程,具有缓慢萌发的特性.这些特性表明分布于较低海拔区域的中国沙棘具有与分布在青藏高原的沙棘属其他种类不同的种子萌发策略.