摘要
为探究土壤氮营养状况对镉(Cd)污染土壤中超富集植物鬼针草叶片光合效率的影响,文章通过控制变量法添加相同质量分数的Cd溶液与不同浓度的氮素溶液进行温室土培实验。结果表明,与对照组相比,施加氮肥后鬼针草叶片的胞间CO_(2)浓度显著降低(P<0.05);叶绿素含量及气孔限制值显著升高(P<0.05);对水汽的气孔导度、对水汽的总导度及对CO_(2)的总导度在氮素含量施加80 mg/kg时显著升高(P<0.05);这些使鬼针草叶片的蒸腾速率、净光合速率、水分利用效率和光能利用效率显著增强(P<0.05),最终鬼针草叶片的光合效率提升(生物量的积累量增加),植物提取的Cd含量增加(P<0.05)。其中,当土壤中施加氮素含量为20 mg/kg时,鬼针草对土壤中Cd的提取量最高,为对照组的2.01倍。因此,土壤中添加氮素能通过提升超富集植物的光合效率,增强其对土壤中重金属的提取量。
In order to study the effect of the nitrogen nutrition status of soil on the photosynthetic efficiency of the leaves of Bidens pilosa L.grown in cadmium(Cd)contaminated soil,greenhouse soil culture experiments were carried out by means of the control variable method involving the adding of same mass fraction of Cd solution and different concentration gradient of nitrogen(N)solution.As a result of the experiments,it was showed when nitrogen content was applied 80 mg/kg(P<0.05)and compared with the control group,the intercellular CO_(2) concentration(Ci)of Bidens pilosa L.leaves decreased significantly(P<0.05);chlorophyll content and stomatal limit value(Ls)increased notably(P<0.05);and stomatal conductance(Gsw),total conductance to water vapor(Gtw)and total conductance to CO_(2)(Gtc)upgraded remarkably.Thereby,transpiration rate(Ts),net photosynthetic rate(Pn),water use efficiency(WUE)and light energy use efficiency(LUE)of Bidens pilosa L.leaves(P<0.05)were remarkably enhanced,and finally the light and efficiency of Bidens pilosa L.leaves(increased biomass accumulation)and the content of Cd extracted by the plants(P<0.05)were increased.It was found,among many others,that when the nitrogen content in soil equaled to 20 mg/kg,the extraction amount of Cd from soil by Bidens pilosa L.attained the highest value,being 2.01 times that of the control group.In sum,the addition of nitrogen to soil can upgrade the photosynthetic efficiency of hyper-accumulated plants and enhance their ability of extracting heavy metals in soil.
作者
郭嘉航
张福琼
黄晶心
杨云
孙世中
熊明月
韩飞
GUO Jiahang;ZHANG Fuqiong;HUANG Jingxin;YANG Yun;SUN Shizhong;XIONG Mingyue;HAN Fei(Yunnan Provincial Observation and Research Station of Soil Degradation and Restoration for Cultivating Plateau Traditional Chinese Medicinal Plants,Yunnan Normal University,Kunming 650500,China;Key Lab of Yunnan Provincial Rural Energy Engineering,Yunnan Normal University,Kunming 650500,China;Wenshan Academy of Agricultural Sciences,Wenshan 663099,China)
出处
《环境科学与技术》
CAS
CSCD
北大核心
2022年第4期146-153,共8页
Environmental Science & Technology
基金
国家自然科学基金青年科学基金项目(31800443)
云南省大学生创新训练项目(202010681098,S202110681058X,S202110681036X)
云南师范大学研究生科研创新基金项目(YJSJJ21-B91)。
关键词
施氮
土壤镉污染
超富集植物
鬼针草
光合效率
nitrogen fertilizer
soil cadmium pollution
hyperaccumulator
Bidens pilosa L.
photosynthetic efficiency
