| 摘要: |
| 【目的】探讨Cd胁迫对巨桉幼树生长和营养元素吸收的影响及巨桉对Cd的富集特征。【方法】2018年5-9月，以1年生巨桉幼树为试验材料，采用盆栽试验，设置5个Cd含量处理，即0 mg/kg（CK）、12.5 mg/kg（T1）、25 mg/kg（T2）、50 mg/kg（T3）、100 mg/kg（T4），10月测定各处理植株的株高、地径并收获全株，测定各器官（吸收根、运输根、主干、枝条、叶）的生物量以及氮、磷、钾、Cd含量，计算各器官的Cd富集系数以及不同处理Cd转运系数。【结果】（1）随着Cd含量的增加，巨桉幼树株高、地径净生长量均呈下降趋势，且T2～T4处理与CK差异达到显著水平；各处理总生物量与CK之间均无显著差异。（2）随着Cd含量的增加，巨桉幼树各组织器官内N、P、K元素含量总体呈降低趋势。（3）随着Cd含量的增加，植株各器官中Cd含量总体均呈增加趋势，且在同一Cd处理水平下，各器官Cd含量由大到小的顺序为吸收根＞运输根＞主干＞枝条＞叶。（4）随着Cd含量的增加，吸收根的Cd富集系数总体呈增加趋势，运输根的Cd富集系数呈先增加后降低的趋势，主干、枝条和叶的Cd富集系数无明显变化规律。随着Cd含量的增加，Cd转运系数呈下降趋势。【结论】巨桉幼树对Cd的转运能力有限，但其生长迅速，即使在高含量Cd胁迫下生长并未受到明显抑制，说明巨桉幼树对Cd有较强的适应性，因此可以初步确定巨桉为重金属Cd污染地区土壤修复树种。 |
| 关键词: 巨桉 镉胁迫 营养元素 镉富集特征 |
| DOI： |
| 分类号: |
| 基金项目:四川省“十三五”农作物育种攻关项目(2016NZ0098-10) |
|
| Growth,nutrients change and cadmium accumulation characteristics of Eucalyptus grandis saplings under cadmium stress |
|
LIU Xijian,CHEN Gang,HU Hongling,et al
|
| Abstract: |
| 【Objective】This study analyzed the effects of Cd stress on growth,nutrient absorption and Cd accumulation characteristics of Eucalyptus grandis saplings.【Method】From May to September 2018,annual giant Eucalyptus grandis sapling were cultivated in pots with five cadmium contents of 0 mg/kg (CK),12.5 mg/kg (T1),25 mg/kg (T2),50 mg/kg (T3) and 100 mg/kg (T4).The plants were harvested in October to determine plant height and ground diameter.Biomasses of different organs (root absorption,transport,roots,trunk,branches and leaves) and contents of nitrogen,phosphorus,potassium and cadmium were measured before cadmium enrichment coefficient of different organs and cadmium transfer coefficients were calculated.【Result】(1) With increasing Cd content,net growth of height and ground diameter of Eucalyptus grandis decreased with significant differences among T2-T4 treatments and CK.There was no significant difference between total biomass of each treatment and CK.(2) With increasing Cd content,contents of N,P and K in tissues and organs of Eucalyptus grandis generally decreased.(3) With the increase of cadmium content,cadmium contents in all organs showed an overall increasing trend.At same cadmium level,cadmium contents in organs were in the order of absorption roots>and transport roots>trunk>branches>leaves.(4) With the increase of cadmium content,bio-concentration factor of absorption roots showed an overall increasing trend,while cadmium enrichment coefficient of transport roots showed a trend of increasing before decreasing.The cadmium enrichment coefficients of trunk,branches and leaves changed insignificantly.With the increase of cadmium content,translocation factor decreased.【Conclusion】The Cd transporting ability of E. grandis saplings was limited,but it grow rapidly and was not significantly inhibited under the stress of high concentration of cadmium,indicating that Eucalyptus grandis had a strong adaptability to cadmium and can be preliminarily screened as a soil remediation tree species in areas contaminated by cadmium. |
| Key words: Eucalyptus grandis cadmium stress nutrient elements Cd enrichment characteristics |
