Abstract: Agropyron michnoi is a perennial bunch grass with short rhizome and high feeding value. In order to study the quantitative characteristics of growth plasticity and the allocation patterns of Agropyron michnoi cohort clones at the second year in the Songnen Plain under artificial planting condition,large sampling analysis was used. The results showed that coefficient of variation of tuft diameter in Agropyron michnoi cohort clones was 31.7%. Coefficient of variation of reproductive and vegetative ramets number were 78.5% and 63.0%,respectively;their coefficient of variation in biomass were 89.8% and 64.3%,respectively. Coefficient of variation of rhizome length and thousand seed weight were 111.4% and 8.4%,respectively. These results indicated that there were different degrees of plasticity in the quantitative characters of clonal modules. The plasticity of production was higher than growth,and the plasticity of quantitative characters of clonal modules in reproductive ramets were higher than vegetative ramets. The plasticity of potential clonal modules was higher than the present modules. The plasticity of the lowest was seed quality,lower than that of other quantitative traits related to growth and sexual reproduction. The regulating function of Agropyron michnoi clones mainly displayed in:the relationship between the clone size and the plasticity of production and growth followed the law of allometric or isogony growth and there was a trade-off between sexual reproduction and vegetative growth.

Key words: Agropyron michnoi, Clonal module, Biomass allocation, Trade-off

摘要： 根茎冰草是多年生短根茎丛生禾草，具有较高的饲用价值。本研究采取大样本取样，对松嫩平原人工建植下根茎冰草二年生同生群无性系的生长与生产的可塑性和规律性进行了定量分析，结果表明：根茎冰草同生群无性系丛径的变异系数为31.7%，生殖株和营养株数量的变异系数分别为78.5%和63.0%，生物量变异系数分别为89.8%和64.3%；根茎长和种子千粒重的变异系数分别为111.4%和8.4%。各构件数量特征均存在不同程度的可塑性，其中，生产特征的可塑性高于生长，构件数量特征的可塑性均以生殖株高于营养株，潜在无性系高于现实无性系；生殖构件生长与分配的数量性状高于种子质量性状。根茎冰草无性系的调节功能主要体现在：无性系大小及构件生长与生产的可塑性均较严格地遵循异速或同速生长规律；生殖分配与营养生长之间存在权衡。

关键词: 根茎冰草, 无性系构件, 生物量分配, 权衡