不同温度环境下3种高寒草地植物种子萌发研究

Seed Germination of Three Alpine Grassland Plants under Different Temperature Environments

针对青藏高原阿里地区高寒草地的植物种子萌发研究,可为该区域草地生物多样性保护以及退化生态系统恢复与重建、退化土地治理提供理论依据。本研究以阿里地区高寒荒漠草地白花枝子花、高原芥、半卧狗娃花为研究对象,通过进行不同恒温条件下3种植物种子的萌发试验,对温度与种子萌发率、种子发芽势、种子发芽指数的关系进行相关性分析。结果表明:在阿里地区的高寒草地上所收集的3种植物种子,5℃时3种植物种子都没有萌发,其中白花枝子花在25℃时种子萌发率、发芽势和发芽指数均为最高,分别为95.5%、88.9%和29.8;高原芥在15℃时萌发率最高,为90%,25℃时发芽势和发芽指数达到最高,分别为75.6%和31.9;半卧狗娃花在20℃时萌发率和发芽势达到最高,分别为71.1%和62.2%,15℃时发芽指数最高,为23.9。通过对3种植物种子萌发结果对比分析表明:白花枝子花、高原芥和半卧狗娃花的最适萌发温度基本都在15℃-25℃,温度过高或过低都会影响种子的萌发。本研究结果不仅对阿里地区维持高寒草地优势种植物群落稳定性及荒漠植物的适应机制提供参考,且对预测该区域植被变化趋势具有重要意义。

The reserech on plant seed germination in alpine grassland in Ali area of Qinghai-Tibet Plateau can provide a theoretical basis for conservation of grassland biodiversity and the restoration and reconstruction of degraded ecosystems and degraded land management in the region.In this study,the germination of seeds of three species of plants in alpine desert grassland of Ali region,which were Dracocephalum hetero phyllum Benth.,Christolea crassifolia Camb.,and Aster semi prostratus(Grierson)H.Ikeda,were tested under different temperature conditions,and the correlation between temperature and seed germination rate,seed germination potential and seed germination index were also analyzed.The results showed that the seeds of the three plants collected in the alpine grassland of Ali region did not germinate at 5°C,but the seed germination rate,germination potential and germination index of Dracocephalum hetero phyllum Benth.Were the highest at 25°C with 95.5%,88.9%and 29.8%,respectively.Christolea crassifolia Camb.had the highest germination rate of 90%at 15°C,and the highest germination potential and germination index at 25°C was 75.6%and 31.9%,respectively.The germination rate and germination potential of Aster semi prostratus(Grierson)H.Ikeda reached the highest at 20°C,71.1%and 62.2%,respectively,and the germination index was the highest at 15°C,23.9%.The comparative analysis of the seed germination results of the three plants showed that the optimal germination temperature of Dracocephalum hetero phyllum Benth,Christolea crassifolia Camb.and Aster semi prostratus(Grierson)H.Ikeda was basically at 15℃-25℃,and either too high or too low temperature would affect the seed germination.The results of this study not only provide a reference for maintaining the stability of plant communities of dominant species in alpine grasslands and the adaptation mechanism of desert plants in Ali region,but also have important implications for predicting the vegetation change trends in the region.