汞胁迫对4个草坪草、牧草品种幼苗生长和生理的影响

Effects of Mercury Stress on Seedling Growth and Physiology of Four Turfgrass and Forage Varieties

本研究以紫花苜蓿‘金皇后’(Medicago sativa‘Golden empress’),多花黑麦草‘盛宴’(Lolium multiflorum‘Feast’)和紫羊茅‘传奇’(Festuca rubra‘Legend’)和‘派尼’(Festuca rubra‘Pernille’)为材料,以含0,30,60,90,120 mg·L^(-1) HgCl_(2)的Hoagland营养液进行沙培盆栽试验,探究不同浓度汞胁迫对4个草种生长和生理的影响。结果表明:随着汞胁迫浓度的升高,4个品种的出苗率、株高、干重、叶面积、叶绿素含量、PS II原初光能转化效率(Fv/Fm)、根系活力和可溶性糖(soluble sugar,SS)含量均呈下降趋势,而丙二醛(malonaldehyde,MDA)含量却呈上升趋势;4个草种的耐汞性及对汞敏感的指标类型存在明显差异;中低浓度汞胁迫(30~60 mg·L^(-1))下,各草种的出苗率、叶面积、株高、干重、根系活力较对照降幅较小;汞胁迫浓度大于90 mg·L^(-1)时,各草种的测定指标均开始急剧变化,出苗率、株高、干重、叶面积、根系活力、叶绿素含量、叶片SS含量均显著降低(P<0.05),而MDA含量显著升高(P<0.05)。4个草种幼苗期耐汞性强弱依次为:‘派尼’>‘金皇后’>‘盛宴’>‘传奇’。本研究可为汞污染土壤植物修复时在植物材料选择方面提供科学参考。

Taking Medicago sativa‘Golden empress’,Lolium multiflorum‘Feast’,Festuca rubra‘Legend’and Festuca rubra‘Pernille’as materials,a pot experiment with Hoagland nutrient solution containing 0,30,60,90,120 mg·L^(-1) HgCl_(2) was conducted to explore the effects of different concentrations of mercury stress on the growth and physiology of four turfgrass and forage varieties.The results showed that with the increase of mercury stress concentration,the seedling percentage,plant height,dry weight,leaf area,chlorophyll content,PS II primary light energy conversion efficiency(Fv/Fm),root activity and soluble sugar(SS)content of four varieties showed a downward trend,while the MDA content showed an upward trend.There were significant differences in mercury tolerance and mercury sensitive index types among four grass varieties.Under medium and low concentrations of mercury stress(30~60 mg·L^(-1)),the seedling percentage,leaf area,plant height,dry weight and root activity of each grass decreased slightly compared with the control.When the concentration of mercury stress was greater than 90 mg·L^(-1),the determination indexes of each variety began to change rapidly,and the seedling percentage,plant height,dry weight,leaf area,root activity,chlorophyll content and SS content were significantly reduced(P<0.05),the MDA content increased significantly(P<0.05).The mercury tolerance of the four grass varieties at seedling stage was in the order of‘Pernille’>‘Golden empress’>‘Feast’>‘Legend’,which could provide scientific reference for the selection of plant materials in phytoremediation of mercury-contaminated soil.