绵刺(Potaninia mongolica)繁殖对策与种群更新的生境选择行为研究

以绵刺地表枯落物水浸液和蒸馏水为对比,对绵刺的种子发芽时间、种子发芽率和幼苗生长速度进行实验。实验结果表明:绵刺地表枯落物水浸液对绵刺种子萌发时间、萌发率和幼苗生长速度相对于蒸馏水有明显地抑制作用。10%枯落物水浸液和2%土壤表层水浸液对绵刺种子萌发时间、种子萌发率和幼苗生长速度抑制作用最为显著;说明绵刺枯落物具有化学他感作用,但这种他感作用与目前研究的异株克生作用不同,它在绵刺母株株丛内,排斥自身种子定居,以无性繁殖扩大对株丛内均质性生境的利用,实现种群的更新;在株丛外,以种子占据异质性生境进行种群的更新。因此,绵刺繁殖对策和生境的选择具有行为性,即绵刺植株以无性繁殖方式进行亲本基因的识别,有效地保存基因,而通过他感排斥作用,使种子携带的基因通过种子扩散器的作用,进行长距离的传播,在新的生境中定居,避免了亲代与子代有限资源的争夺,传播基因,这种繁殖策略的采用和生境的选择行为既保存了基因,又提高了种群的适合度。

Reproduction Strategy and Alternative Behaviors for Habitat in Regeneration of Potaninia Mongolica Maxim

The allelopathic effects of Potaninia mongolica on its seed gremination was given. Compared to distilled water, the acqueous extracted from aerial parts deadwood on ground in genet bush of Potaninia mongolica causes inhibition on germination time,germination rate and seedling growth speed obviousely. It has the most distict hibitition effect on sprout time, germination and seedling growth speed in 10% of acqueous extracted from aerial parts deadwood on ground and 2% of acqueous extracted from soil underground 2 cm. The results show that there is allelopathy in genet bush of Potaninia mongolica to exclude it is difficult for seed reproduction in Potaninia mongolica its seed for settlement. Owing to allelopathy existence, genet bush. On the contrary, it is fit for seed of Potaninia mongolica to gemination and settle in the rain stream where is far away from genet to develop generating pop- ulation of Potaninia mongolica. However, there are population generations by clonal ramets in genet bush of Potaninia mongolica. The alternative propagation strategies are chosen for Potaninia mongolica to utilize the different environment resources. Heterologous environment resource is used to enlarge habitation and maintain variation by the special organ named distributing material. New environment resource was utilized to keep inheritance by clonal growth. In this reproduction behavior, Potaninia mongolica conserves not only genes but fitness.