Telenius Anders, Torstensson Peter
Dept. of Botany, Sect. of Ecology, University of Stockholm, S-106 91, Stockholm, Sweden.
Oecologia. 1989 Aug;80(2):206-210. doi: 10.1007/BF00380152.
The seeds of the halophyte Spergularia marina differ both within and between individuals in that they either possess or lack a membranaceous border. This paper presents a morphological study of the length, weight and area of the seed types, and their dispersal characteristics under experimental conditions of wind and water dispersal. The winged seeds are shown to be larger both by length and by weight. Their rate of descent increases with wing loading. If the wing is lacking, however, the rate of descent increases with weight only. The distance of dispersal is equal for both seed types except at low wind speeds, when the winged seeds disperse farther. If the seed wing is removed, the excised seeds have shorter dispersal distances. When dispersed by water, a difference in the distance seeds are dispersed can only be detected in the presence of vegetation. The winged seeds are more frequently trapped in the vegetation as compared to the unwinged seeds. The hypothesis that the seed dimorphism is an adaptation for differential dispersal distances is discussed.
盐生植物滨海米口袋的种子在个体内部和个体之间存在差异，即它们有的有膜质边缘，有的没有。本文对种子类型的长度、重量和面积进行了形态学研究，并研究了它们在风和水传播的实验条件下的传播特性。有翅种子在长度和重量上都更大。它们的下降速度随翼负荷增加。然而，如果没有翅膀，下降速度仅随重量增加。除了在低风速下有翅种子传播得更远外，两种种子类型的传播距离相等。如果去掉种子的翅膀，切除翅膀的种子传播距离较短。当通过水传播时，只有在有植被的情况下才能检测到种子传播距离的差异。与无翅种子相比，有翅种子更频繁地被困在植被中。本文讨论了种子二态性是对不同传播距离的一种适应这一假说。
