Abstract: Leymus secalinus is a herbaceous clonal plant with long-rhizome，which is considered to be a qualified forage grass. It plays an important role in the theory and practice to study the plasticity and regularity on module growth of L. secalinus clones in the early stage of the establishment. In order to quantitatively analyze the quantitative characters and plasticity of L. secalinus clonal module,we used the method of the whole clones being dug up. The results showed that there was a great change in coefficient of variation in the module growth of L. secalinus clones after a growth season. The maximum coefficient of variation was buds at tillering-node,which was 107.9%,and the plasticity was the highest. The minimum coefficient of variation in length of rhizomes was 29.4%,and the plasticity was the lowest. The plasticity of the biomass of ramet and rhizome was higher than their number. With the increase of rhizome length,the biomass of rhizomes and ramets significantly (P<0.01) increased with linear function of isogony growth,the number of ramets,total buds and buds on rhizome significantly (P<0.01) increased with a power function of allometry growth. L. secalinus clones had the principle that the module growth in ramet number was superior to rhizome elongation.

Key words: Leymus secalinus, Clone, Module, Growth plasticity, Isogony growth, Allometry growth

摘要： 赖草（Leymus secalinus）是长根茎型无性系优良禾草，研究建植初期无性系构件生长的可塑性及其规律具有重要理论与实践意义。本试验采用整个无性系完整挖掘的方法，定量分析了其无性系构件生长的数量特征和可塑性。结果表明，经过一个生长季，赖草无性系构件的生长均具有较大的变异系数，其中，分蘖节芽的最大，为107.9%，可塑性最大。间隔子长度的最小，为29.4%，可塑性最小；分株和根茎均以生物量的可塑性高于其数量。随着根茎长度的增加，根茎和分株的生物量均呈极显著（P<0.01）线性函数同速生长，分株数量、总芽数和根茎芽数均呈极显著（P<0.01）幂函数异速生长。赖草无性系具有分株数量优先于根茎伸长的构件生长原则。

关键词: 赖草, 无性系, 构件, 生长可塑性, 同速生长, 异速生长