不同草本植物对铜镍复合胁迫的生理耐受性

Physiological tolerance of different herbaceous plants to copper-nickel combined stress

为探究草本植物在铜镍复合胁迫下的生理生长响应及其耐受性,以4种甘肃主栽的草本植物(黑麦草、早熟禾、清水苜蓿和鹰嘴紫云英)为研究对象,采用盆栽试验,通过设置不同铜镍复合胁迫浓度(0、100、200、400、800、1600 mg·kg^(-1)),测定植物的生长和生理生化指标,并利用线性逐步回归和隶属函数分析法综合评价4种草本植物在铜镍复合胁迫下的耐受性。结果表明:铜镍复合胁迫下,4种植物的株高、地上和地下生物量、叶绿素a、叶绿素b及叶绿体色素含量、叶片相对含水量和根系活力显著降低(P<0.05),与CK相比,分别下降86.83%~90.54%、49.40%~61.50%和44.44%~82.25%、24.47%~44.26%、45.91%~70.22%、25.04%~36.59%、17.59%~20.98%和14.71%~69.32%;根冠比、可溶性糖和可溶性蛋白含量、SOD、POD和CAT活性先升高后降低,其峰值较CK分别上升1.42%~35.88%、264.91%~743.65%和65.93%~327.81%、23.23%~86.38%、131.62%~176.93%和72.42%~85.87%;丙二醛、游离脯氨酸以及类胡萝卜素含量显著升高(P<0.05),分别上升40.62%~62.90%、235.34%~1060.04%和576.17%~1282.58%;根、茎、叶中Cu 2+和Ni^(2+)含量增加,不同器官的Cu^(2+)和Ni^(2+)含量不同。回归分析筛选出地下生物量、可溶性糖、可溶性蛋白、脯氨酸、Cu^(2+)含量及SOD活性作为筛选耐铜镍植物的关键指标。隶属函数综合评价得出4种草本植物的耐铜镍能力为:紫花苜蓿(0.565)>鹰嘴紫云英(0.538)>早熟禾(0.449)>黑麦草(0.448),可作为耐铜镍植物筛选及土壤生物修复应用的参考依据。

To explore the physiological growth response and tolerance of herbaceous plants under copper-nickel combined stress,four main herbs of Lolium perenne‘Cutter’,Poa pratensis‘Midnight’,Medicago sativa‘Qingshui’and Astragalus sinicus‘Lutana’in Gansu Province were planted and their biomass and physiological biochemical indexes were determined by setting different copper-nickel compound stress concentrations of 0,100,200,400,800 and 1600 mg·kg^(-1).Linear stepwise regression and membership function analysis were used to comprehensively evaluate the tolerance of four herbs under copper-nickel combined stress.The results showed that the plant height,aboveground and underground biomass,chlorophyll a,chlorophyll b,total pigment content of chloroplasts,relative water content and root activity of the four plants were significantly reduced by copper-nickel compound stress(P<0.05).Compared with CK,the decrease ranges were 86.83%~90.54%,49.40%~61.50%,44.44%~82.25%,24.47%~44.26%,45.91%~70.22%,25.04%~36.59%,17.59%~20.98%and 14.71%~69.32%,respectively.The root-crown ratio,soluble sugar and soluble protein content,SOD,POD and CAT activities increased first and then decreased,and the peak increase range was 1.42%~35.88%,264.91%~743.65%,65.93%~327.81%,23.23%~86.38%,131.62%~176.93%and 72.42%~85.87%,respectively.The contents of malondialdehyde,free proline and carotenoids increased significantly(P<0.05)ranged from 40.62%~62.90%,235.34%~1060.04%,576.17%~1282.58%,respectively.The content of Cu^(2+)and Ni^(2+)in roots,stems and leaves increased,and the contents of Cu 2+and Ni^(2+)in different organs were different.Regression analysis screened subsurface biomass,soluble sugars,soluble proteins,proline,Cu^(2+)content and SOD activity as key indicators for selecting copper-nickel-resistant plants.The copper-nickel tolerance of four herbaceous plants was obtained by the comprehensive evaluation of the membership function:Medicago sativa(0.565)>Astragalus sinicus(0.538)>Poa pratensis(0.449)>Lolium perenne(0.448).This study can be used as a reference for the screening of copper-nickel resistant plants and soil bioremediation applications.