五种植物根系受损愈伤自修复的力学特性

Mechanical properties of callus self-repair with damaged roots of five plants

[目的]本文旨在为选择优良的水土保持植物种类提供一定的基础力学数据。[方法]本文以内蒙古自治区鄂尔多斯市准格尔旗东部的黑岱沟露天煤矿排土场相同立地条件下用于土地复垦的3~4年生小叶锦鸡儿(Caragana microphylla Lam)、中国沙棘(Hippophae rhamnoides Linn)、杨柴(Hedysarum laeve Maxim)、沙打旺(Astragalus adsurgens Pall)、紫花苜蓿(Medicago sativa L)为研究对象,利用数显式推拉力计和自制便携试验机台,对其根径直根进行原位拉伸试验,研究70%极限拉力受损后待根系愈伤自修复3个月后力学特性的变化特征,以探讨外力机械损伤后根系自修复后力学特性的种间差异性共同规律。[结果]实验组在3个月愈伤自修复后的直根的存活率、活性值、极限抗拉力和抗拉强度均低于平行对照组,且根径与存活率和抗拉强度呈负相关,与极限抗拉力呈正相关。5种植物的种内平行对照和愈伤自修复后的极限抗拉力差异性均显著(P<0.05),而极限抗拉强度则只有小叶锦鸡儿和沙打旺存在显著性差异(P<0.05)。愈伤自修复后抗拉力学特性恢复效应为:紫花苜蓿>杨柴>沙打旺>中国沙棘>小叶锦鸡儿;活性值稳定性顺序为:紫花苜蓿>小叶锦鸡儿>沙打旺>杨柴>中国沙棘。在代表根径级1~1.5 mm范围内,种内平行对照和实验组之间的极限抗拉力和抗拉强度均存在显著性差异(P<0.05),且5种植物平行对照和实验组的直根极限抗拉力和抗拉强度大小顺序均为:小叶锦鸡儿>中国沙棘>杨柴>沙打旺>紫花苜蓿。[结论]草本植物的恢复效应优于半灌木和灌木。

[Objective]The research provided basic mechanical data for the selection of plant species with excellent conservation ability for soil and water in the process of vegetation restoration and reconstruction.[Methods]This study was conducted in the Heidaigou open-pit coal dump located at the eastern part of Zhungeer Banner,Ordos City,Inner Mongolia Autonomous Region used for land reclamation under the same site conditions.Five plant species including Caragana microphylla,Hippophae rhamnoides,Hedysarum laeve,Astragalus adsurgens,and Medicago sativa were selected as the research objects.A digital display force gauge and a self-made portable testing machine were used to conduct an in-situ tensile test on straight roots with a root diameter between 1 and 4 mm to study the changes of mechanical characteristics.When 70%of the ultimate tensile force was damaged,the root system had three months to heal and self-repair.The change characteristics of mechanical properties were used to explore the influence of external mechanical damage on the self-repairing of root mechanical properties,and to reveal the differences between species and the common law of mechanical properties.[Results]The survival rate,activity value,ultimate tensile strength and tensile strength of taproot in the experimental group after three months callus self-repair were lower than those of the parallel control group,and the root diameter was negatively correlated with survival rate and tensile strength,and positively correlated with tensile strength.Intraspecific parallel control and callus self-repair of five plants had significant difference in ultimate tensile strength(P<0.05),while only C.microphylla and A.adsurgens had significant difference(P<0.05).The recovery effect of the tensile mechanical properties of the callus after self-repair was:M.sativa>H.laeve>A.adsurgens>H.rhamnoides>C.microphylla.The order of activity value stability was:M.sativa>C.microphylla>A.adsurgens>H.laeve>H.rhamnoides.Within the range of 1~1.5 mm of representative root diameter,there were significant differences in the ultimate tensile strength and tensile strength between the intraspecific parallel control and the experimental group(P<0.05).The order of the ultimate tensile strength and tensile strength of taproot after restoration was:Caragana microphylla>Hippophae rhamnoides>Hedysarum laeve>Astragalus adsurgens>Medicago sativa.[Conclusion]The restoration effect of herbaceous plants is better than sub-shrubs and shrubs.