汞胁迫对4个草坪草品种幼苗生长及汞富集能力的影响

Effects of Mercury Stress on Seedling Growth and Mercury Enrichment Capacity of Four Turfgrass Cultivars

【目的】为优选出适宜于贵州汞矿废弃地及汞污染环境植被恢复的草坪草品种。【方法】分别选取适合南方种植的4个草坪草品种(多年生黑麦草马达、一年生黑麦草盛宴、紫羊茅派尼和传奇)作为试验材料,以发芽试验(Hg^2+浓度0,30,60,90,120,150 mg/L胁迫)和土培试验(Hg^2+浓度0,25,50,75,100 mg/kg)探讨4个品种在Hg^2+不同浓度胁迫环境下的种子萌发、幼苗生长状况和富集能力。【结果】随着Hg^2+浓度升高4个品种的发芽率、发芽势、发芽指数和活力指数均受到明显抑制,盛宴和马达的耐受极限为120 mg/L;在试验浓度范围内,种子发芽率为派尼>传奇>盛宴>马达。高浓度Hg^2+明显抑制4个品种的生长,随着Hg^2+浓度升高,成活率持续下降;当Hg^2+浓度达100 mg/kg时,成活率为盛宴>派尼>传奇>马达。【结论】在试验浓度范围内,盛宴在汞胁迫下的综合长势最好,但在含Hg^2+浓度25 mg/kg土壤中富集能力较强,适用于低汞土壤的恢复和草坪建植,传奇在含Hg^2+浓度50和100 mg/kg土壤中的富集能力较强,适用于高汞土壤的恢复和草坪建植。

【Objective】This paper aims to select turf grass cultivars suitable for vegetation restoration in Guizhou mercury mine wasteland and mercury pollution environment.【Method】Four turfgrass cultivars suiting southern China,including Motor,Feast,Pernille,and Legend,were selected as the experimental materials.The seed germination test and soil culture test under different concentration of Hg^2+stress were conducted to explore the seed germination and seedling growth of four cultivars.【Result】With Hg^2+concentration increasing,the germination rate,germination potential,germination index and vigor index of the four cultivars were obviously inhibited.The tolerance limit of Feast and Motor was 120 mg/L;In the range of experimental treatment,the seed germination rate of the four cultivars was Pernille>Legend>Feast>Motor.The growth of the four cultivars was inhibited by high Hg^2+concentration,and the survival rate of the four cultivars decreased with the Hg^2+increasing.When the concentration of Hg^2+reached 100 mg/kg,the survival rate of the four cultivars was Feast>Pernille>Legend>Motor.【Conclusion】In the range of experiment,the comprehensive growth of Feast under Hg^2+stress was the best.However,Feast showed stronger enrichment ability in mercury-containing 25 mg/kg soil,which was suitable for restoration of low-mercury soil and establishment of lawn,Legend had the strongest ability to enrich mercury in mercury-containing 50 and 100 mg/kg soil,which was suitable for restoration of high-mercury soil and establishment of lawn.