| 摘要: |
| 【目的】探讨铅（Pb）胁迫对杉木幼苗生长与营养元素吸收的影响及Pb的富集与转移特性。【方法】以1年生杉木幼苗为试验材料，采用盆栽试验，设置0（CK）、250 mg/kg（T1）、500 mg/kg（T2）、750 mg/kg（T3）、1 000 mg/kg（T4）和1 500 mg/kg（T5））Pb胁迫处理，测定不同处理杉木幼苗的形态（株高、地径）、生物量、叶片光合色素含量及各器官（吸收根、运输根、主干、枝、叶）中氮（N）、磷（P）、钾（K）、Pb含量，计算各器官的Pb富集系数和不同处理的Pb转运系数。【结果】①随着土壤中Pb含量的增加，杉木幼苗株高、地径净生长量以及总生物量均呈先升高后下降的趋势，但各处理株高净生长量与CK之间均无显著差异，T4、T5处理地径净生长量和总生物量与CK差异达到显著水平。②随着土壤中Pb含量的增加，叶绿素a、叶绿素b和总叶绿素含量呈先升后降的趋势，其中T5处理的叶绿素a和总叶绿素含量显著小于CK，其余各处理与CK无显著差异，各处理间叶绿素b和类胡萝卜素含量无显著差异。③随着土壤中Pb含量的增加，杉木幼苗各器官的N、K元素含量均呈先升高后下降的趋势；而地下部分P元素含量总体呈上升趋势，地上部分则呈先上升后下降趋势,吸收根、运输根、枝、叶P元素含量均显著大于CK。④随着土壤中Pb含量的增加，杉木幼苗各器官中Pb含量呈上升趋势，且在同一Pb胁迫处理下，各器官Pb含量由大到小依次为吸收根、运输根、主干、叶、枝。⑤随着土壤中Pb含量的增加，杉木幼苗各器官Pb富集系数总体呈先升高后下降的趋势，各处理间Pb转运系数无显著差异。【结论】杉木幼苗对Pb的转运能力有限，但在低含量Pb胁迫环境中生长受到促进，由于杉木生长迅速，因此可将其作为低含量Pb污染地区的造林树种。 |
| 关键词: 杉木 铅胁迫 营养元素 铅富集系数 铅转运特征 |
| DOI： |
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| 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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| Changes in growth and nutrient contents of Cunninghamia lanceolata (Lamb.) Hook. seedlings under lead stress and characteristics of lead enrichment |
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GUAN Peng,HU Hongling,DAI Dachuan,et al
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| Abstract: |
| 【Objective】Effects of lead (Pb) stress on growth and nutrient absorption of Cunninghamia lanceolata (Lamb.) Hook seedlings and characteristics of Pb enrichment and transfer were investigated.【Method】One-year-old C. lanceolata seedlings were planted in pots with Pb stress of 0 (CK),250 mg/kg (T1),500 mg/kg (T2),750 mg/kg (T3),1 000 mg/kg (T4) and 1 500 mg/kg (T5).The morphology (plant height and ground diameter),biomass,photosynthetic pigment content in leaves as well as nitrogen (N),phosphorus (P),potassium (K) and Pb contents in organs (absorptive root,transport root,trunk,branch and leaf) were determined,and Pb enrichment coefficients in organs and Pb transport coefficients in different treatments were calculated.【Result 】① With the increase of soil Pb content,plant height,ground diameter net growth and total biomass of C.lanceolata seedlings increased first and then decreased.There were no significant differences in plant height net growth among groups,while there were significant differences in ground diameter net growth and total biomass among T4,T5 and CK.② With the increase of soil Pb content,chlorophyll a,chlorophyll b and total chlorophyll increased firstly and then decreased.The chlorophyll a and total chlorophyll of T5 treatment were significantly less than those of CK,and there were no significant differences in chlorophyll b and carotenoids among treatments.③ With the increase of soil Pb content,contents of N and K in organs of C.lanceolata seedlings increased firstly and then decreased.P content increased in the underground part,and it increased first and then decreased in the aboveground part.P contents in absorbent root,transport heel,branch and leaf in treatments were significantly higher than those in CK.④ With the increase of soil Pb content,Pb contents in organs of C.lanceolata seedlings increased,and the decreasing order among organs was absorption root,transport root,trunk,leaf and branch.⑤ With the increase of soil Pb content,Pb enrichment coefficients increased firstly and then decreased,and there was no significant differences in Pb transport coefficient among different treatments.【Conclusion】C. lanceolata seedlings had limited Pb transport capacity,but the growth was promoted under low Pb stress environment.Because of the rapid growth,C. lanceolata seedlings can be used as affo restation species in low Pb polluted areas. |
| Key words: Cunninghamia lanceolate (Lamb.) Hook lead stress nutrient elements lead enrichment factor lead transport characteristics |
