南京林业大学学报(自然科学版) ›› 2021, Vol. 45 ›› Issue (3): 61-70.doi: 10.12302/j.issn.1000-2006.202103020

• 研究论文 • 上一篇    下一篇

7种杨树铅抗性和积累能力的比较研究

石文广1(), 李靖2, 张玉红1,3, 雷静品1, 罗志斌1,*()   

  1. 1.林木遗传育种国家重点实验室,国家林业和草原局森林培育重点实验室,中国林业科学研究院林业研究所,北京 100091
    2.南京林业大学轻工和食品学院,江苏 南京 210037
    3.和瑞基因科技有限公司,北京 100102
  • 收稿日期:2021-03-09 修回日期:2021-04-06 出版日期:2021-05-30 发布日期:2021-05-31
  • 通讯作者: 罗志斌
  • 基金资助:
    中国林业科学研究院中央级公益性科研院所基本科研业务费专项资金(CAFYBB2018GD001);中国林业科学研究院中央级公益性科研院所基本科研业务费专项资金(CAFYBB2019ZA001-1);中国林业科学研究院中央级公益性科研院所基本科研业务费专项资金(CAFYBB2018SY005)

A comparative study on lead tolerance and accumulation of seven poplar species

SHI Wenguang1(), LI Jing2, ZHANG Yuhong1,3, LEI Jingpin1, LUO Zhibin1,*()   

  1. 1. State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Silviculture of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
    2. College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing 210037, China
    3. Berry Oncology Technology Co., Ltd., Beijing 100102, China
  • Received:2021-03-09 Revised:2021-04-06 Online:2021-05-30 Published:2021-05-31
  • Contact: LUO Zhibin

摘要:

【目的】通过对比研究不同种杨树的铅(Pb)抗性和Pb积累能力,筛选具有修复Pb污染土壤潜力的杨树树种。【方法】选取7种速生杨树,用8 mmol/L Pb处理6周,分析7种杨树Pb抗性和积累能力。【结果】Pb胁迫导致7种杨树净光合速率、气孔导度和蒸腾速率降低,抑制了7种杨树的高生长和径向生长,其中欧洲黑杨、群众杨和青杨的光合和生长对Pb胁迫较敏感,美洲黑杨敏感性较低。Pb胁迫导致7种杨树生物量显著降低,其中欧美杨根生物量降低最多(50.31%),欧洲黑杨(31.99%)和群众杨(22.26%)木材生物量降低最显著,欧美杨(12.67%)和群众杨(19.54%)皮生物量降低最显著,灰杨叶生物量降低最多(35.44%)。7种杨树的总生物量在Pb胁迫下出现明显降低,其中灰杨降幅最大(29.03%),欧洲黑杨降幅最小(12.02%)。相应地,7种杨树Pb抗性指数大小顺序依次为:欧洲黑杨(88.09%)>银腺杨(82.98%)≈美洲黑杨(80.70%)>欧美杨(79.86%)>青杨(76.79%)>群众杨(72.78%)≈灰杨(70.35%)。7种杨树吸收和转运Pb的能力存在较大差异。美洲黑杨根中的Pb含量最高,达2 906.10 mg/kg;灰杨木材、皮和叶中的Pb含量较高,分别达46.55、44.39和325.90 mg/kg。美洲黑杨根和整株Pb积累量最大,分别为4.20和5.06 mg/株;灰杨地上部分Pb积累量最大,为1.21 mg/株。美洲黑杨的根富集系数最大,达6.70;灰杨地上部分富集系数最大,为0.43。灰杨的Pb转运系数显著高于其他杨树,达0.16;欧洲黑杨的转运系数最低,仅为0.02。【结论】7种杨树的Pb抗性和Pb积累能力存在明显差异,其中欧洲黑杨Pb抗性最强、美洲黑杨根吸收Pb的能力最强,可能在Pb污染土壤的植物固定和生态恢复方面具有较大潜力;灰杨转运Pb能力最强,地上部分Pb积累能力最强,可能在Pb污染土壤的植物提取方面具有较大潜力。

关键词: 杨树, 植物修复, Pb胁迫, 光合作用, 生物量, Pb积累, 土壤重金属污染

Abstract:

【Objective】In this study, we aimed to find the promising poplar species for the remediation of lead (Pb)-contaminated soil by comparing the lead (Pb) resistance and accumulation of different poplar species. 【Method】Seven fast-growing poplar species were exposed to 8 mmol/L Pb(NO3)2 for 6 weeks to analyze their capacities for Pb tolerance and accumulation. 【Result】The net photosynthetic rate, stomatal conductance and transpiration rate were significantly reduced in the leaves of Pb-exposed poplar plants compared to those under the controlled condition. Thus, the axial and radial growth of poplar plants were inhibited by Pb exposure. The photosynthesis and growth of Populus nigra, P. × popularis and P. cathayana were more sensitive, and those of P. deltoides were less sensitive to Pb exposure than the other poplar species. The biomass of Pb-treated poplar plants was declined in comparison with that of poplar plants under the controlled condition. The greatest reduction in root biomass was found in P. × euramericana (50.31%); the significant decreases in wood biomass were found in P. nigra (31.99%) and P. × popularis (22.26%); the significant decreases in bark biomass were found in P. × euramericana (12.67%) and P. × popularis (19.54%); the greatest reduction in leaf biomass was found in P. × canescens (35.44%). The total biomass of the seven poplar species decreased significantly under Pb stress. The largest decrease was found in P. × canescens (29.03%), and the smallest reduction was found in P. nigra (12.02%). Correspondingly, the tolerance index of the seven poplar species was decreased in the order: P. nigra (88.09%) > P. alba × P. glandulosa (82.98%) ≈ P. deltoides (80.70%) > P. × euramericana (79.86%) > P. cathayana (76.79%) > P. × popularis (72.78%) ≈ P. × canescens (70.35%). Significant differences in absorption and transport of Pb were found among poplar species. P. deltoides displayed the highest Pb concentration in the roots (2 906.10 mg/kg). P. × canescens showed the highest concentrations of Pb in the wood (46.55 mg/kg), bark (44.39 mg/kg) and leaves (325.90 mg/kg). The total Pb amount in the roots (4.20 mg/plant) and whole plant (5.06 mg/plant) of P. deltoides and those in the aerial part (1.21 mg/plant) of P. × canescens were the largest among the seven poplar species. P. deltoides showed the highest bio-concentration factor of roots (6.70) and P. × canescens displayed the highest bio-concentration factor of the aboveground tissue (0.43). Meanwhile, P. × canescens displayed the highest translocation factor (0.16), and P. nigra showed the lowest translocation factor (0.02). 【Conclusion】Significant differences in Pb tolerance and accumulation were found among the seven poplar species. Among which, P. nigra and P. deltoides displayed the strongest abilities for Pb tolerance and absorption, respectively, and thus both species may have great potentials for phytostabilization and ecological restoration of Pb-polluted soil. P. × canescens showed the strongest ability to transport Pb to the aboveground tissues, and thus it may have a great potential for phytoextraction of Pb in contaminated soil.

Key words: Populus spp., phytoremediation, Pb stress, photosynthesis, biomass, Pb accumulation, soil heavy metal pollution

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