张咏梅, 胡海英, 白小明, Matthew Cory, García-Favre Javier, Ordóñez Iván P. 多年生黑麦草、雀麦根系形态和生长对土壤干旱的适应性[J]. 中国生态农业学报 (中英文), 2022, 30(11): 1784−1794. DOI: 10.12357/cjea.20220336
引用本文: 张咏梅, 胡海英, 白小明, Matthew Cory, García-Favre Javier, Ordóñez Iván P. 多年生黑麦草、雀麦根系形态和生长对土壤干旱的适应性[J]. 中国生态农业学报 (中英文), 2022, 30(11): 1784−1794. DOI: 10.12357/cjea.20220336
ZHANG Y M, HU H Y, BAI X M, CORY M, JAVIER G F, IVÁN P O. Effects of soil water restriction on root growth and root morphology of perennial ryegrass and pasture brome[J]. Chinese Journal of Eco-Agriculture, 2022, 30(11): 1784−1794. DOI: 10.12357/cjea.20220336
Citation: ZHANG Y M, HU H Y, BAI X M, CORY M, JAVIER G F, IVÁN P O. Effects of soil water restriction on root growth and root morphology of perennial ryegrass and pasture brome[J]. Chinese Journal of Eco-Agriculture, 2022, 30(11): 1784−1794. DOI: 10.12357/cjea.20220336

多年生黑麦草、雀麦根系形态和生长对土壤干旱的适应性

Effects of soil water restriction on root growth and root morphology of perennial ryegrass and pasture brome

  • 摘要: 为了研究牧草根系对干旱环境的适应性, 选择多年生黑麦草(Lolium perenne)和雀麦(Bromus valdivianus)进行盆栽试验, 给予80%~85%有效水(PAW)充分供水和20%~25% PAW极端干旱两种水分模式, 通过对两种牧草的根系外形、干物质积累和根系形态学分析, 探求两牧草在极干旱胁迫下的有效生产策略。研究表明, 两种牧草的根尖外形略有不同。雀麦根毛长而密, 分生区细胞致密, 伸长区较长; 多年生黑麦草根毛稀疏, 伸长区短。20%~25% PAW极干旱胁迫使黑麦草根系粗细不匀, 出现畸形; 而雀麦根系未见明显受害。两种牧草生物量在茎叶和根的积累无显著的种间差异和水分处理间的组间差异。雀麦和多年生黑麦草单株根系的总长度、根面积、根平均直径、根尖数和分叉数存在极显著差异。多年生黑麦草根量显著高于雀麦(至少P≤0.01), 根长和面积是雀麦的1.5倍左右, 根尖数和分叉数是雀麦的2倍以上。雀麦根系末端侧根分枝密度高, 短且粗; 多年生黑麦草侧根细而长。干旱胁迫显著减少了两种牧草的总根长度, 促进了雀麦根的径向生长。总之, 雀麦根毛区较多年生黑麦草发达, 多年生黑麦草根量显著多于雀麦。黑麦草主要以根数量(量)取胜, 采取广泛吸水的适应策略; 雀麦以根毛发达, 侧根分枝密度高(质)为主, 采用确保有效吸水的适应策略。

     

    Abstract: To study the adaptability of herb roots to drought environments, perennial ryegrass (Lolium perenne) and pasture brome (Bromus valdivianus) were supplied 80%–85% plant available water (PAW) and 20%–25% PAW in a pot experiment. By analyzing of root appearance, biomass accumulation, and root morphology of perennial ryegrass and pasture brome, an effective production strategy for the two forage grasses under extreme drought stress was explored. The results showed that the appearance of the root tips differed slightly between the two forage grasses. Pasture brome had long and dense root hair and a long elongation area in the root tips, whereas perennial ryegrass had sparse root hair and a short elongation area. Extreme drought stress (20%–25% PAW) resulted in uneven root thickness and malformation in perennial ryegrass. No obvious damage was observed in pasture brome roots. There was no significant difference between species and soil water content in terms of biomass accumulation and distribution in the shoots and roots of the two forage grasses. However, there were significant differences in root length, root area, root diameter, root tips, and root forks between the perennial ryegrass and pasture brome. The root quantity of perennial ryegrass was significantly higher than that of brome (P≤0.01); the root length and root area were approximately 1.5 times those of pasture brome; and the root tips and forks were more than twice those of pasture brome. Pasture brome roots were significantly thicker than perennial ryegrass roots, with root diameters of 0.315 mm and 0.259 mm, respectively. The lateral root branches of the pasture brome root were short, thick, and dense, whereas the lateral roots of the perennial ryegrass were long and thin. Drought stress significantly reduced the total root length of the two forage species and promoted the radial growth of roots in the pasture brome. In conclusion, pasture brome had a more developed root-hair-area, and perennial ryegrass had more root quantity. Therefore, perennial ryegrass is distinguished mainly by its root quantity and adopts an adaptive strategy of extensive water absorption, whereas pasture brome is distinguished by well-developed root hair, high lateral root branch density (quality), and adaptive strategies to ensure effective water absorption.

     

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