异形狭果鹤虱的二型性种子萌发特性及其生态适应

Germination Characteristics and Ecological Adaptation of Dimiorphic Seeds of L.Semiglabra

[目的]研究异形狭果鹤虱种子的二型性现象。[方法]通过形态、扩散特征,观察和萌发实验对异形狭果鹤虱的二型性种子进行研究。[结果]长刺小坚果与短刺小坚果的刺长、百粒重存在显著差异,长刺小坚果在扩散中占优势,种子的传播距离与种子萌发率均成正相关。两者的萌发率也存在显著差异,且长刺小坚果对短刺小坚果的萌发存在抑制作用。异型种子都存在萌发休眠现象,短刺小坚果在不同温度下的萌发率变化较小,延长储藏时间可以提高异型种子的萌发率。[结论]异形狭果鹤虱种子二型性扩大了种子萌发的时间范围,增加对环境条件的适合度,有利于其在高度严酷的环境中成功定居和繁衍。

[ Objective ] To study the phenomenon of L. semiglabra that can produce two types of seeds. [ Method ] We compared the morphology, spread and germination characteristics of two types of seeds by morphological observation and germination experiment. [ Result ] This two types of seeds differ in length of glochids^weight of 100 nutlets and germination rate. Nutlets with long glochids are easier to fall off and spread further. At the same time, it can restrain the germination of nutlets with short glochids. The germination rate of short glochids has little change in different temperature. Percentage germination of both seeds was increased by extending the storage time. [ Conclusion ] Seed dimorphism may allow L. semiglabra to survive in harsh desert haitats