不同密度梯度下串珠老鹳草个体大小依赖的繁殖分配

Size Dependent Reproductive Allocation of Geranium transversale at Different Density Gradients

为研究密度对串珠老鹳草繁殖生物量分配的影响,以性多态植物串珠老鹳草(Geranium transversale)为研究对象,设置3个种群密度:15、25、50株/m2进行野外控制性试验,测量了不同密度下串珠老鹳草各器官生物量特征,分析了不同密度下营养器官与繁殖器官生物量分配差异性以及个体大小与繁殖分配间的关系。结果表明,3个种群密度梯度下串珠老鹳草地下生物量及其繁殖器官生物量分配比例存在显著差异(P<0.05),表现出明显的密度制约效应;繁殖分配比例随密度增大呈显著增加趋势(P<0.05),表明高种内竞争压力下串珠老鹳草将更多资源分配给繁殖器官;在不同密度下,串珠老鹳草的繁殖分配随个体大小的增大而增加(P<0.01)。串珠老鹳草可通过调整地上与地下间的资源分配来提高应对种内竞争压力增大的适应能力。

To study the effects of density on reproductive biomass allocation on Geranium transversale,by investigating the biomass characteristics of organs of individuals sizes under different densities of the experimental sit with three density gradients set:15 plant/m2,25 plant/m2,and 50 plant/m2,and the relationship between vegetative organs and reproductive organs,and the relationship between individual size and reproductive allocation under different densities were analyzed.The results showed that:Below ground organ biomass and reproductive organs biomass allocation were significantly different under the three density gradients(P<0.05),which showed a density-dependent effect;The proportion of reproductive allocation increased significantly with the increase of density(P<0.05),indicating that G.transversale allocated more resources to reproductive organs under high intraspecific competition pressure;The reproductive allocation of G.transversale increased with the increase of individual size under different densities(P<0.01).Therefore,G.transversale could adjust the rate and proportion of resources allocation between aboveground and underground to improve its adaptability to the increase of intraspecific competition pressure.