植物的表型可塑性、异速生长及其入侵能力

表型可塑性是指同一个基因型对不同环境响应产生不同表型的特性,特定性状的可塑性本身可以遗传,也可以接受选择而发生进化。植物个体的异速生长是指生物体某一特征的相对生长速率不等于第二种特征的相对生长速率的特性,该特性是由物种的遗传性决定的一种固定特征,植物往往朝着最佳的异速生长曲线进化。植物特定基因型在不同环境下,诸如生物量分配和种群几何学上的一些表型差异,既可由异速生长造成,也可由表型可塑性造成。植物本身的异速生长是一种"外观可塑性",而异速生长曲线的改变才是真正的可塑性。植物的表型可塑性、异速生长对于入侵植物的适应具有重要意义。干扰等异质性生境下表型可塑性成为物种生存扩散的有利性状,表型可塑性强的物种更有可能成为广布种。植物本身的异速生长特性或其异速生长曲线的改变都能影响其入侵能力。

Phenotypic plasticity, allometry and invasiveness of plants

Phenotypic plasticity is the property that a given genotype can produce different phenotypes in response to various environmental conditions,and a trait that has a certain genetic basis and can evolve independently.Allometry is used to study and measure the relative growth of one part of an organism,in comparison with the other parts of the organism.The allometry of a plant individual can be seen as a fixed trait determined by the inheritance of species,and plants evolve towards optimal allometric trajectory.The phenotypic variations of a specific genotype under different environmental conditions such as biomass allocation and community geometry difference may result from allometric growth and phenotypic plasticity as well.The allometry of a plant can be seen as 'apparent plasticity',whereas the real plasticity is the change of the allometric trajectory.Both phenotypic plasticity and allometry are the important traits for the invasiveness of plants.The species with higher phenotypic plasticity would adapt to more heterogeneous habitats,and phenotypic plasticity would become a better trait for the survival and spread in heterogeneous environment.The plant invasiveness can be influenced by both the allometry of plant and the change of allometric trajectory.