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码上扫一扫！ |
| 桢楠幼树生长和营养元素吸收对镉胁迫的响应及其镉富集特性 |
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官鹏, 铁得祥, 胡红玲, 陈刚, 李闯, 李冬豪, 邓雯
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四川农业大学 林学院，四川 成都 611130
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| 摘要: |
| 【目的】分析镉（Cd）对桢楠(Phoebe zhennan)幼树生长和各器官中营养元素含量及分配模式的影响，探讨桢楠对Cd的耐受能力及富集性，以正确选择桢楠的适生立地。【方法】以3.5 a桢楠幼树为试验材料，采用盆栽控制试验，设置0(CK),10,20,30,40和50 mg/kg 6个Cd（以CdCl2形式施入）处理水平，分5次施入，每2月施1次，试验结束后测定不同处理桢楠的叶面积、株高、根系活力和各个器官（叶、枝、主干、运输根、吸收根）的生物量及其N、P、K、Mg、Fe、Cd含量，计算各器官的Cd富集系数（BCF）和不同处理的Cd转运系数（TF），分析桢楠对镉胁迫的响应及其对镉的富集和转运特性。【结果】①当第4次施入CdCl2约15 d后，除CK外，其余Cd处理植株叶缘均出现枯萎现象，且随Cd胁迫的加重其叶缘枯萎面积逐渐增大。②与CK相比，桢楠幼树株高净生长量在Cd处理水平≥20 mg/kg时显著（P<0.05）降低，总生物量、根系活力则是所有Cd处理均受到显著（P<0.05）抑制。③随施Cd量的增加，叶、枝、主干中的N含量总体呈降低趋势，吸收根中的N含量呈先降后增趋势且各处理均显著低于CK，而运输根中的N含量在各处理与CK间均无显著差异；枝和吸收根中的P含量均较CK显著降低，运输根中的P含量在施Cd量≥40 mg/kg时显著降低，而叶片和主干中的P含量在50 mg/kg Cd处理时显著高于CK；运输根中的K含量自20 mg/kg Cd处理开始显著低于CK，其余器官中的K含量在各水平Cd处理下均较CK显著降低；运输根中Mg含量在各水平Cd处理下均较CK增高，其中10，20和50 mg/kg Cd处理显著增高，而各水平Cd处理下其他器官中的Mg含量均与CK无显著差异；除10 mg/kg Cd处理外，其余Cd处理下叶中Fe含量均较CK显著增高，但枝和主干中Fe含量分别在施Cd量大于等于50和40 mg/kg时显著低于CK，而在运输根和吸收根中各Cd处理Fe含量均与CK无显著差异。④随施Cd量的增加，吸收根、叶和枝中的Cd含量均呈增加趋势，主干和运输根的Cd含量呈先增后减趋势，且同一施Cd水平下，各器官中的Cd含量由大到小依次为吸收根、主干、运输根、叶、枝。⑤ 随施Cd量的增加，桢楠幼树叶和吸收根对Cd的BCF呈增加趋势，主干对Cd的BCF与CK相比无显著变化，枝和运输根的BCF呈降低趋势，且分别在施Cd水平大于等于20和30 mg/kg时显著低于CK；各施Cd处理桢楠植株的TF均显著低于CK，且各器官BCF和植株TF均小于1。【结论】桢楠幼树耐Cd性较弱，其对Cd的BCF和TF均小于1，在施Cd量≥10 mg/kg时TF即显著下降，表明其富集Cd的能力有限，不宜在Cd污染严重地区种植及用于污染土壤修复。 |
| 关键词: 桢楠 镉胁迫 幼树生长 营养元素吸收 镉富集性 |
| DOI：10.13207/j.cnki.jnwafu.2025.03.002 |
| 分类号: |
| 基金项目:四川省“十三五”农作物育种攻关项目（2016NZ0098-10） |
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| Response of growth and nutrient absorption of Phoebe zhennan saplings to cadmium stress and its bioaccumulation characteristics for cadmium |
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GUAN Peng, TIE Dexiang, HU Hongling, CHEN Gang, LI Chuang, LI Donghao, DENG Wen
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College of Forestry,Sichuan Agricultural University,Chengdu,Sichuan 611130,China
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| Abstract: |
| 【Objective】The effects of cadmium (Cd) on the growth of Phoebe zhennan saplings and nutrient content and distribution patterns in various organs were analyzed.In order to select a suitable site for breeding,the Cd tolerance and enrichment of P.zhennan were investigated.【Method】The 3.5-year-old P.zhennan saplings were used as the experimental materials,and the pot control test was used,and 6 Cd (in the form of CdCl2) treatment levels were set up at 0(CK),10,20,30,40 and 50 mg/kg,which were applied in 5 times,once every 2 months,and after the experiment,the leaf area,plant height,root activity and biomass of each organ (leaf,branch,trunk,transport root,absorbing root) and the content of N,P,K,Mg,Fe and Cd of different treatments were measured.The Cd bioaccumulation factor (BCF) of each organ and the Cd translocation factor (TF) of different treatments were calculated to analyze the response of P.zhennan to cadmium stress and its enrichment and transport characteristics to cadmium.【Result】① About 15 days after the fourth application of CdCl2,the leaf margins of plants treated with Cd,except CK,were all withered,and the area of leaf margins withered gradually increased with the increase of Cd stress.② Compared with CK,the net plant height growth of P.zhennan saplings was significantly decreased (P<0.05) when the Cd treatment level was greater than or equal to 20 mg/kg,while the total biomass and root activity were significantly inhibited (P<0.05) by all Cd treatments.③ With the increase of Cd application,the N content in leaves,branches and trunk showed a decreasing trend,and the N content in absorbing roots showed a trend of first decreasing and then increasing,and the N content in each treatment was significantly lower than that of CK,while there was no significant difference in N content in transport roots between each treatment and CK.The P content in branches and absorbing roots was significantly lower than that in CK,but the P content in transport roots decreased significantly when the dosage of Cd was 40 mg/kg, while the P content in leaves and trunk was significantly higher than that in CK treatment at 50 mg/kg Cd.The K content in transport roots was significantly lower than that in CK when treated with 20 mg/kg Cd, and the K content in other organs was significantly lower than that in CK under Cd treatment at all levels.The Mg content in transporter roots was significantly higher than that of CK under Cd treatment at all levels,and the Mg content in 10,20 and 50 mg/kg Cd treatment was significantly increased,while the Mg content in other organs was not significantly different from that of CK in other organs under Cd treatment at all levels.Except for the 10 mg/kg Cd treatment,the Fe content in the leaves under other Cd treatments was significantly higher than that of CK,but the Fe content in the branches and trunk was significantly lower than CK when the dosage of Cd was 50 and 40 mg/kg,respectively,while the Fe content in the transport root and absorbing root treated with Cd was not significantly different from that in CK.④ With the increase of Cd application,Cd content in absorbing roots,leaves and branches increased,and Cd content in trunk and transport roots increased first and then decreased,and under the same Cd application level,Cd content in each organ was in the order of absorbing roots,trunks,transport roots,leaves and branches from large to small.⑤ With the increase of Cd application,the BCF of Cd in the leaves and absorbing roots of P.zhennan saplings showed an increasing trend,the BCF of Cd in the trunk did not change significantly compared with CK,and the BCF of branches and transport roots decreased.The levels of Cd at 20 and 30 mg/kg were significantly lower than those of CK,respectively.The TF of P.zhennan plants in each Cd treatment was significantly lower than that of CK,and the BCF and TF of each organ were less than 1.【Conclusion】The Cd tolerance of P.zhennan saplings was weak,and its BCF and TF for Cd were both less than 1,and the TF decreased significantly when the Cd application amount was greater than 10 mg/kg.The Cd enrichment ability of P.zhennan saplings was limited,and it was not suitable for planting in Cd polluted areas and for soil remediation. |
| Key words: Phoebe zhennan cadmium stress growth of saplings nutrient absorption cadmium enrichment |
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