• 关键词：砷污染  大豆  生长  氮  磷  钾

• 基金项目：湖北省教育厅科学技术研究计划重点项目(No.D20091009)

• 杨兰芳
• 湖北大学资源环境学院,武汉 430062

• 彭小兰
• 中国科学院南京土壤研究所,南京 210008

• 裴艳艳
• 湖北大学资源环境学院,武汉 430062

• 陈瑞雪
• 湖北大学资源环境学院,武汉 430062

• 摘要：利用土壤盆栽实验,研究了0、5、10、30、50、100 mg·kg^-1的土壤加砷水平对大豆生长和氮、磷、钾养分含量的影响.结果表明,当土壤加砷水平达到50 mg·kg^-1时,大豆出现中毒症状,叶片皱缩,叶色变暗,叶缘焦枯,植株矮化,成熟延迟.大豆株高随加砷水平的提高而降低,并呈极显著的负指数相关关系.土壤加砷达到100 mg·kg^-1时,大豆株高减少41.5%,总生物量减少43.4%,籽粒产量减少56.1%.高砷(100 mg·kg^-1)水平下,根、茎叶与地上部分生物量的比值显著增加,而籽粒与茎叶、地上部分、总生物量的比值显著降低,表明高含量砷抑制了地上部分和籽粒生物量的形成.土壤砷污染对大豆各部位氮、磷、钾含量和分配也有显著影响,当土壤加砷水平达到100 mg·kg^-1时,同对照相比,大豆籽粒、根、茎叶的氮、磷含量均显著增加,籽粒含钾量降低,茎叶和根含钾量增加,籽粒与茎叶、籽粒与根的氮、磷、钾含量的比值均显著降低,说明高砷胁迫抑制了茎叶中的养分向籽粒转移.总体而言,土壤砷超过50 mg·kg^-1时会对大豆造成毒害,大豆通过调节各部位氮、磷、钾含量来适应砷污染环境,高砷毒害的实质是通过抑制大豆根系和茎叶中的氮、磷、钾养分向地上部分和大豆籽粒转移从而抑制地上部分的生长和大豆籽粒的形成.

• Abstract：Arsenic (As) is toxic to plants and animals. A soil pot experiment with the arsenic addition levels of 0, 5.0, 10.0, 30.0, 50.0, 100.0 mg·kg^-1 was conducted to investigate the effects of soil arsenic addition on soybean growth and the content of nitrogen, phosphorus and potassium. The results showed that when soil arsenic addition was at a level of 50 mg·kg^-1, soybean demonstrated a series of toxic symptoms with crimple and dark green leaves, withered leaf edge, dwarfing plant and delayed maturation. The plant heights of soybean decreased with increase of soil arsenic supplement and there was significant negative, exponential correlation between the soil arsenic additions and plant heights of soybean. Soil arsenic addition of 100 mg·kg^-1 caused 41.5% decrease in plant height, 43.4% in total biomass and 56.1% in the yield of soybean grain. The ratio of root biomass to that of aerial parts and of biomass of leaf and stem to that of aerial parts increased, while the ratio of grain biomass to that of leaf and stem, aerial parts and total biomass was decreased. These results suggested that high soil arsenic addition suppressed the growth of aerial parts and grain. Soil arsenic pollution had significant effects on the content of nitrogen, phosphorus and potassium in soybean. When soil arsenic addition was 100 mg·kg^-1, compared to control (no arsenic addition), soybean nitrogen and phosphorus content in grains, roots and leaves and stems, potassium content in leaves and stems and in roots increased significantly, but the potassium content in grains decreased significantly, while the ratio of nitrogen, phosphorus and potassium content in soybean grains to that in leaves and stems and to that in roots decreased significantly. This implied that arsenic stress suppressed the translocation of the nitrogen, phosphorus and potassium in leaves and stems to grains. In summary, over 50.0 mg·kg^-1 soil arsenic addition could be toxic to soybean growth, but soybean could adapt to the arsenic polluted environment by adjusting the content of nitrogen, phosphorus and potassium in various parts. The essence of arsenic toxicity to soybean growth was to inhibit the growth of soybean aerial parts and the formation of soybean grains because of the suppression of the translocation of nitrogen, phosphorus and potassium in roots, leaves and stems to grains.

• Key words：arsenic pollution  soybean  growth  nitrogen  phosphorus  potassium

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