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.