青藏高原东缘高寒草甸常见植物种子形状对萌发的影响

以青藏高原东缘高寒草甸383种常见植物种子为材料,分析种子萌发特性与种子形状(长、宽、高的三维方差)、体积及相对表面积之间的相关性,研究高寒草甸地区植物种子性状对其萌发特性的影响。结果显示:(1)种子萌发率和萌发速率与种子三维方差、相对表面积呈极显著正相关,与体积呈显著负相关;(2)种子平均萌发时间与种子体积呈显著正相关、与种子相对表面积呈显著负相关、与种子三维方差无显著相关性。表明体积较小而形状细长的种子具有较高的萌发率及萌发速率,体积大而圆的种子需要更长的萌发时间;小种子具有较大的相对表面积可能是其具有较高萌发率和萌发速率的原因之一。研究结果为土壤种子库形成机制的研究提供了一定的理论依据。

Effect of Seed Shape on Germination in an Alpine Meadow on the Eastern Qinghai-Tibet Plateau

The relationship between seed germination characteristics and seed shape (three-dimensional variance of length, width, and height), seed volume, and surface/volume ratio were studied. We discussed the influence of seed shape and size on seed germination. The results showed that: (1) germination percentage and germination rate were both significantly positively correlated with variances in dimension and surface/volume ratio, and significantly negatively correlated with seed volume; (2) mean seed germination time was significantly negatively correlated with seed volume, but significantly positively correlated with seed surface/volume ratio, and the variances in dimension and seed volume had no obvious effects on mean germination time. Accordingly, small, elongated seeds had higher germination percentages and rates, while large, compact seeds showed a delay in germination. The small seeds had a larger surface/volume ratio, which might explain their higher germination percentage and rate. Our study provides a theoretical basis for the formation mechanism of a soil seed bank.