温度和光照对半干旱草原植物种子萌发的影响

Effects of Temperature and Light on Seeds Germination in Semi-arid Grasslands

本文以典型草原植物物种为例研究温度和光照对种子萌发的影响,结果表明:种子的萌发特性在物种间存在显著差异;温度显著地影响种子萌发开始时间和萌发率,低温延迟了种子萌发的开始时间并降低了种子萌发率,但是对萌发持续时间影响不显著;相对于温度,光照对萌发开始时间、持续时间及萌发率的影响较为微弱,仅对个别物种有影响.本研究结果表明,萌发开始时间易受环境条件变化的影响,萌发率次之,而萌发持续时间则最为保守.在全球气候变化的背景下,植物种子的这种特异性响应可以用来解释群落结构的变化.

Effect of temperature and light on seeds germination characteristics of eight typical steppe species was tested. Our results show that seed germination characteristic varies greatly among species. Temperature has a significant effect on both the day to first germination and germination percentage, but no effect on germination period. Generally, low temperature delays the day to first germination and decreases germination percentage. The effects of light on day to first germination, germination period and germination percentage are relatively weak compared with temperature, and the impacts are species dependent. We conclude that germination start time is the most susceptible to the changing environmental condition, followed by germination rate, whereas germination duration is the most conservative characteristic. We suggest that the specific response of plant seeds should be used to explain the change of community composition under global change scenario.