Abstract: In order to study the organ biomass distribution of plants with different plant heights and understand its survival strategies,Achnatherum inebrians growing in grassland habitats was selected as the research object,and the growth characteristics of A. inebrians with three different plant heights (large,medium and small) was determined. The results showed that there was no significant difference (P>0.05) between leaves and roots biomass of A. inebrians under different plant heights,but difference among other organs (i.e. stems and spikes) was significant (P<0.05). There was no significant difference in the root biomass allocation among different plant heights (P>0.05). The higher the plant height,the more the biomass allocation of inflorescence and stem,but the less the biomass of leaf (P<0.05). The order of biomass ratio of vegetative components and reproductive components of A. inebrians within three plant heights was large stump>medium stump>small stump,with values of 1.202,0.486 and 0.373,respectively. There was no significant difference in root-shoot ratio among different plant heights(P<0.05). With the increase of plant height,the biomass of leaves/stems and roots/inflorescences decreased significantly (P<0.05),while the others were not affected by the change of plant height (P>0.05). The biomass of inflorescences and stems,the total biomass and stem,leaf and root biomass showed a very significant positive correlation relationship (P<0.01),and there was no significant difference between other components. That the results of the biomass allocation and the relationship between the components under different plant heights showed its flexible growth and resource allocation strategy.

Key words: Achnatherum inebrians, Plant height, Biomass allocation, Root-shoot ratio

摘要： 为了研究不同株高对醉马草（Achnatherum inebrians）器官生物量分配的影响，从而更好地了解其整体的生存策略，本试验以生长在草原生境下的醉马草为对象，测定大株、中株、小株3种株高的醉马草生长特性。试验结果表明，不同株高醉马草除了叶和根生物量之间没有显著性差异（P>0.05）外，穗和茎生物量以及总生物量之间均有显著性差异（P<0.05）；醉马草株高越高穗和茎生物量分配越多，叶生物量分配越少（P<0.05），对根生物量分配没有影响（P>0.05）；3种株高醉马草生殖构件与营养构件生物量比例大小顺序依次为大株>中株>小株，其值分别为1.202、0.486和0.373，不同株高醉马草种群根冠比没有显著差异（P>0.05）；随醉马草株高的增加，叶生物量/茎生物量和根生物量/穗生物量的比值显著减小（P<0.05），叶生物量/穗生物量、叶生物量/根生物量、根生物量/茎生物量和茎生物量/穗生物量的比值均不受株高大小变化的影响（P>0.05）。醉马草各构件间除了穗生物量和茎生物量，总生物量与茎、叶、根生物量间表现为极显著正相关外（P<0.01），其他构件之间没有显著性差异。可见，不同株高下醉马草的生物量分配及各构件之间的关系，显示了其灵活的生长和资源分配策略。

关键词: 醉马草, 株高, 生物量分配, 根冠比