禾本科植物在青藏高原分布较广,选取该地47种常见禾本科植物,观测其种子大小变异,并在人工气候室内做萌发试验,研究了在变温(12 h 10 ℃/12 h 20 ℃)、无光照条件下,禾本科植物的种子大小对萌发特性的影响.结果表明:高寒草甸禾本科植物种子百粒重范围为0.006 9～1.436 3 g,平均重量为0.192 1 g,重量大小变异达到了近3个数量级.60%的种子在0.006 9～0.148 9 g,种子大小聚类分析后,归为组1的有28个物种(0.006 9～0.148 9 g),说明高寒草甸禾本科以较小的种子占绝对优势.种子大小与萌发指数、萌发率都成正相关,与萌发开始时间呈负相关,这说明对于高寒草甸禾本科植物来说,种子越小萌发越快,萌发开始时间越早,而萌发率却越低,反之亦然.试验结果反映了禾本科植物种子大小在一定程度上对萌发特性起着重要的作用.
Seed size variation and its relationship to germination for familiar species of Gramineae on the eastern Qinghai-Tibet Plateau
Gramineous plants distribute widely on Qinghai-Tibet Plateau. 47 gramineous species in this area were chosen and the variation of the seed size was observed. After germination experiment in a plant growth chamber, the effect of seed size on the germination characteristics of gramineous plants under two different temperature regimes without light was studied. The result demonstrated that: the weight of alpine meadow gramineous plant seeds varied from 0. 006 9 g to 1. 436 3 g, their average weight was 0. 1921g and the weight variation nearly reached 103. 60% of the seeds within a weight range of 0. 006 9~0. 148 9 g. After cluster analysis on seed size, 28 species were clustered into group 1 (0. 006 9~0. 148 9 g) , which illuminated that small seeds gramineous plants possessed the absolute superiority in alpine meadow. Under the temperature variation(12 h 10℃/12 h 20℃) , the seed size showed positive correlation with germination ratio and index, whereas negatively correlated with beginning germination time. All these phenomena demonstrated that for alpine meadow gramineous plants the smaller the seed size was, the faster and earlier its seeds germinated, but also the lower the germination rate was (vice verse). The experiment results demonstrated that the seed size of gramineous plants had significant meaning to their germination characteristics to some extent.
国家科技期刊平台
NSTL
万方数据
维普
