羊草根茎克隆形态可塑性研究进展

Advances in studies on morphological plasticity of Leymus chinensis rhizome

羊草(Leymus chinensis)是典型根茎型禾草,可通过根茎克隆形态可塑性来适应不同逆境。本文分析总结了盐碱胁迫、土壤、水分等环境因子和群落环境、草地利用方式等生态学因子对羊草根茎克隆形态可塑性的影响,并就该领域未来研究进行了展望。分析表明,羊草通过增加间隔子长度,以迅速逃离盐碱胁迫斑块;贫瘠的土壤环境中,羊草节间距缩短,根茎节数增加,以增加须根来获取养分;疏松的土壤和充足的水分有利于羊草生长和克隆繁殖;群落环境对羊草根茎克隆繁殖产生复杂影响;长期过度放牧不利于羊草克隆繁殖,表现为根茎长度指标降低,芽和分株减少;刈割时间和频次也有影响。羊草等草地根茎型植物未来研究中,应简化研究指标;重点研究群落环境和扰动的影响;借助现代科学技术来揭示其通过根茎可塑性来适应逆境的机理。

Leymus chinensis is one of the typical rhizomatous grasses, of which rhizome morphological plasticity is the major strategy to adapt to different adversities. This paper includes a review on research achievements on the effects of environmental (such as salt and alkali stress, soil, and water) and ecological (such as community environment and grassland use) factors on the morphological plasticity of L. chinensis rhizomes. The future research in this field is also prospected. Leymus chinensis rapidly escaped from patches with saline alkali stress by increasing spacer length. In poor soil, the length of the internode was shortened and the number increased, which increased fibrous roots to obtain nutrients. Loose soil and adequate moisture were beneficial for the growth and clonal reproduction of L. chinensis. Community environment has complex effects on clonal reproduction via the rhizomes. Long-term overgrazing was not conducive to clonal reproduction of L. chinensis, which showed that the length of rhizomes and the number of buds and ramets decreased. Mowing time and frequency also had an effect. In future studies on rhizomatous plants, such as L. chinensis, research indexes should be simplified, the influence of community environment and disturbance should be mainly studied, and we should try to reveal the mechanisms of adaptations to adversities via rhizomes using modern science and technology.