小麦油菜种群个体大小不等性的研究

A PRELIMINARY STUDY OF THE SIZE HIERACHY IN THE POPULATIONS OF TRITICUM AESTIVUM AND BRASSICA CAMPESTRIS

本文报导了春小麦(Triticum destivum)和油菜(Brassica campestris)种群内个体间的干扰竞争对个体大小不等性的影响。结果表明,小麦和油菜种群的个体大小不等性随种群密度的加大而提高,油菜提高的趋势比小麦明显。植株生殖枝干重的大小不等性较生物干重大。植株营养期的大小不等性较成熟期为小。相邻植株的距离与个体大小有一定相关性。试验结果表明,个体间的干扰竞争是植物种群个体大小等级形成的重要因子。即种群内较大的个体抑制了较小个体的生长,从而加大了植株大小的相对差异和种群生物量集中于少数较大的个体的趋势。

In an investigation of the effects of interference competition on size hierachy(sizeinequality)in spring wheat(Triticum aestivum L.)and oilseed rape(Brassica campestris),size inequality,esp.that of oilseed rape,appeared to increase with population density,theinequality in reproductive output estimated by dry mass of ears or siliques was greater thanthat in plant dry mass,the size inequality in vegetative growth periods was less striking thanthat in the maturing period,and the nearest neighbour distance(NND)of individuals wasrelated to their size.Such results support the interference competition model in which largeplants are able to usurp more resources and suppress the growth of their smallerneighbours.