干旱胁迫对不同根型苜蓿根系构型的影响

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 干旱胁迫对不同根型苜蓿根系构型的影响 DOI: 10.5846/stxb202109042504 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金（32160327）；甘肃省重点研发计划项目（20YF3FA011） Effects of drought stress on root architecture of different root- type alfalfa Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:采用盆栽试验，比较播种当年及生长第2年对照、中度、重度干旱胁迫下根茎型、直根型、根蘖型苜蓿根系平面、立体几何构型和分形特征差异，以探究不同根型苜蓿对干旱的适应策略。结果表明：随干旱胁迫增加，各根型苜蓿根系总长度、总表面积、总体积和平均直径均减小；各根型苜蓿的根系拓扑指数较小，根系分支模式为叉状分支结构；各根型苜蓿的根系具有较好的分形特征，其分形维数较小，而分形丰度和平均连接长度均较大，表明其根系分支相对简单，但空间拓展能力强，有利于对营养空间的占有；各根型苜蓿的总分支较小、逐级分支率较大，有助于资源的快速获取和促进主根的向下生长。对根系构型参数进行主成分分析，根系总表面积、分形丰度、根长、根体积、分形维数和比根长6个根系构型参数能较好反映不同根型苜蓿根系构型特征。重度胁迫下，根茎型、根蘖型苜蓿的根系总长度、总表面积、总体积、比根长、比表面积、平均连接长度均大于直根型苜蓿，表明根茎型、根蘖型苜蓿适应干旱环境的能力强于直根型苜蓿。 Abstract:To investigate the ecological adaptation strategies of drought stress on root plane and stereo geometry architecture and fractal characteristics, pot experiment using three root types of alfalfa (rhizomatous rooted Medicago sativa ‘Qingshui’, tap rooted M. sativa ‘Longdong’, creeping rooted M. varia Martin. ‘Gongnong’ No.4) as the experimental materials was conducted to set up the drought treatment experiments. The results showed that the total root length, total surface area, total root volume and root average diameter of different root-type alfalfa decreased with increasing of drought concentration. The root topological indices of different root-type alfalfa were small, and the root branching patterns were herring-bone-like. The roots of different root-type alfalfa had obviously fractal characteristics, and the fractal dimension was small, while the fractal abundance and the average link length were large, which indicated that they had simple root architecture and high ability to expand living space. Smaller branching ratio and larger stepwise branching rate of different root-type alfalfa were helpful to speed resource acquisition and promote taproot growth downward. Root architecture parameters were analyzed by the principal component analysis. The parameters of total surface area, fractal abundance, total root length, total root volume, fractal dimension, and specific root length could well present the root architecture characteristics of different root-type alfalfa. Under severe stress, the total root length, total surface area, total root volume, specific root length, and specific surface area of rhizomatous rooted and creeping rooted alfalfa were higher than tap rooted alfalfa, which showed that the adaptation to drought environment of rhizomatous rooted and creeping rooted alfalfa were stronger than that of tap rooted alfalfa. 参考文献 相似文献 引证文献