| 摘要: |
| 【目的】研究2个樟科树种养分积累及利用效率对镉（Cd）污染的响应特征，探讨2个树种在重金属Cd胁迫条件下维持养分平衡能力的差异及对镉污染土壤的适应能力。【方法】以长江流域的典型樟科树种香樟和油樟为试验材料，研究不同Cd污染处理（0.12，2.5和5 mg/kg，对应处理编号分别为对照、T1和T2）对2个树种各器官中N、P、K含量和积累量、分配模式、化学计量比以及养分利用效率的影响。【结果】与对照相比，Cd污染条件下香樟N、P、K含量与积累量等指标大多没有显著变化，而油樟的这些指标常常在胁迫条件下显著下降。Cd污染并未影响N、P、K在香樟各器官中的分配比例，但T2条件下油樟N、P、K向叶片的分配比例均显著增加。各种Cd处理条件下2个树种的N/P均小于14，Cd污染引起2个树种茎中的N/P和粗根中P/K变化显著。与对照相比，T1和T2处理下香樟的N、P、K利用效率未发生显著变化，而油樟的N、P、K利用效率提高。【结论】在Cd污染条件下，与香樟相比，油樟在维持N、P、K吸收与分配及维系养分平衡等方面对重金属Cd胁迫更为敏感，受到的负面影响较大；在Cd污染区域，更适合栽培香樟用以修复土壤环境。 |
| 关键词: 镉污染 养分分配 樟科 养分利用效率 |
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| 基金项目:四川省科技厅应用基础项目（2013JY0083）；国家自然科学基金项目（31300513）；“十二五”国家科技支撑计划项目（2011BAC09B05）；四川省教育厅基础研究项目（13ZB0280） |
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| N,P and K accumulation and allocation pattern of Cinnamomum camphora and C.longepaniculatum seedlings under Cd pollution |
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CHEN Lianghua,XU Rui,YANG Wanqin,et al
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| Abstract: |
| 【Objective】The nutrient accumulation and nutrient use efficiency in two Lauraceae species was detected to discuss the differences in maintaining nutrient balance between them and to estimate their adaptation capacity in soils polluted by heavy metals.【Method】Two typical species in Yangtze River basin, i.e.,Cinnamomum camphora and C.longepaniculatum,were used to detect effects of different cadmium (Cd) pollution levels (0.12 mg/kg,CK;2.5 mg/kg,T1;and 5 mg/kg,T2) on content,accumulation,allocation pattern,stoichiometric ratio,and nutrient use efficiency of N,P,and K.【Result】Compared to control,there was no significant change in most parameters in contents and accumulations of N,P,and K in C.camphora when exposed to Cd pollution.In contrast,most of these parameters significantly decreased in C.longepaniculatum.Cd pollution did not significantly affect the nutrient allocation pattern of N,P and K in C.camphora,whereas the allocated N,P and K to leaves increased in C.longepaniculatum under T2.In all conditions,the ratios of N to P in all organs of both species were lower than 14.N/P changed greatly in stems,while P/K varied greatly in coarse roots in both species.Compared to control,there was no significant change in use efficiencies of N,P or K in C.camphora,whereas C.longepaniculatum exhibited higher N,P and K use efficiencies.【Conclusion】C.longepaniculatum was more sensitive to heavy metal stress,and had more negative effects than C.camphora in terms of nutrient uptake,allocation,and maintenance of nutrient balance under Cd pollution.Therefore,C.camphora is more suitable for remediation of Cd polluted soils than C.longepaniculatum. |
| Key words: Cd pollution nutrient allocation Lauraceae nutrient use efficiency |
