| 摘要: |
| 【目的】比较不同水淹胁迫程度对轻木（Ochroma lagopus）幼苗生长、生物量积累以及碳（C）、氮（N）、磷（P）化学计量特征的影响，探究轻木对不同水淹环境的适应性。【方法】以6个月生轻木幼苗为试验材料，设置不进行水淹胁迫的对照（CK）、轻淹胁迫(QY)、中淹胁迫(ZY)和深淹胁迫(SY) 4个处理，16 d后测算轻木幼苗的生长指标、各器官生物量以及C、N、P含量及其比值，对各指标进行主成分分析,并计算其表型可塑性指数。【结果】随水淹程度加重，轻木幼苗的苗高增长量较CK显著降低，但地径增长量与CK差异不显著。QY处理轻木幼苗叶生物量较CK显著上升；随水淹程度加重，茎生物量先下降后上升再下降，根生物量、总生物量以及根冠比呈下降趋势。水淹胁迫对轻木幼苗叶和根C含量影响显著，QY处理叶C含量最低（405.9 mg/g），ZY处理根C含量最低（407 mg/g）。水淹胁迫使幼苗各器官N含量显著高于CK，QY、ZY和SY处理叶N含量较CK显著上升8.8%～27.2%，茎N含量显著上升34.8%～53.2%，根N含量显著上升33.0%～118.3%。随水淹胁迫程度加重,叶P含量先下降后上升再下降，茎P含量先下降后上升，根P含量较为稳定。与CK相比，轻木幼苗各器官C/N比均呈下降趋势；随水淹胁迫程度加重，叶C/P比先上升后下降再上升，茎C/P比先上升后下降，根C/P比变化不显著。轻木幼苗各器官N/P比均小于14，表明轻木幼苗的生长主要受N限制。主成分分析表明，根、茎生物量和总生物量以及根C/N比、茎C/P比和茎N/P比权重系数较大。表型可塑性指数计算结果表明，茎和根生物量以及茎N/P比、茎P、茎C/P比表型可塑性指数较大。【结论】水淹胁迫抑制了轻木幼苗的生长，轻木幼苗主要通过改变茎、根生物量和总生物量的分配以及茎P含量和N/P比、C/P比以及根C/N比来适应水淹环境。因此，在降雨频繁的雨季应对轻木做好排水工作，由于轻木生长受N限制较大，可施适量氮肥以恢复其长势。 |
| 关键词: 轻木 水淹胁迫 生长 化学计量学 |
| DOI：10.13207/j.cnki.jnwafu.2025.10.006 |
| 分类号: |
| 基金项目:国家自然科学基金项目（32071688） |
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| Effects of waterlogging stress on the growth and carbon,nitrogen and phosphorus stoichiometric characteristics of Ochroma lagopus seedlings |
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LIU Chengyao1, XIAO Jiandong1, WU Junwen1, GU Jianyao1, DUAN Huaijiao1, DU Guanben2
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1.College of Forestry,Southwest Forestry University,Kunming,Yunnan 650224,China;2.College of Materials and Chemical Engineering,Southwest Forestry University,Kunming,Yunnan 650224,China
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| Abstract: |
| 【Objective】The effects of different degrees of waterlogging stress on Ochroma lagopus seedling growth,biomass accumulation and carbon (C),nitrogen (N),phosphorus (P) stoichiometric characteristics were compared to explore the adaptability of O.lagopus to different waterlogging environments.【Method】The six-month-old O.lagopus seedlings were used as experimental materials,and the control (CK),light waterlogging stress (QY),moderate waterlogging stress (ZY) and heavy waterlogging stress (SY) were set up.After 16 days,the growth indexes,biomass of each organ C,N,P contents and their ratios were measured,and the phenotypic plasticity index was calculated.【Result】With the increase of waterlogging degree,the increment of seedling height was significantly lower than that of CK,but the increment of basal diameter was not significantly different from that of CK.Compared with CK,leaf biomass of O.lagopus seedlings increased significantly under QY treatment,and stem biomass decreased first,then increased and then decreased,while root biomass,total biomass and root-shoot ratio decreased.The C content of O.lagopus leaves and roots was significantly affected by waterlogging stress.The C content of leaves was the lowest under QY treatment (405.9 mg/g),and the C content of roots was the lowest under ZY treatment (407 mg/g).Compared with CK,the N contents in leaves increased significantly by 8.8%-27.2% under QY,ZY and SY treatments,the N contents in stems increased significantly by 34.8%-53.2%,and the N content in roots increased significantly by 33.0%-118.3%.The P content in leaves first decreased,then increased and then decreased with the increase of waterlogging stress,the P content in stems first decreased and then increased,and the P content in roots was relatively stable.The ratio of C/N in each organ of O.lagopus seedlings showed a downward trend.The C/P ratio of leaves increased first,then decreased and then increased with the increase of waterlogging,the C/P ratio in stems increased first and then decreased,and the C/P ratio in roots did not change significantly.The N/P ratio in each organ of O.lagopus seedlings was all less than 14,and the C/P ratio in leaves was higher than that in stems,indicating that the growth of O.lagopus seedlings was mainly restricted by N.Principal component analysis showed that the weight coefficients of root,stem biomass and total biomass,root C/N ratio,stem C/P ratio and stem N/P ratio were higher.The results of the phenotypic plasticity index calculation showed that stem and root biomass and stem N/P ratio,stem P,stem C/P ratio was higher.【Conclusion】Waterlogging stress inhibited the growth of O.lagopus,and the seedlings adapted to waterlogging environment by changing the allocation of stem,root and total biomass,stem P content,stem N/P ratio,stem C/P ratio and root C/N ratio.Therefore,in the rainy season when the rainfall is frequent,the drainage work should be conducted well.Because the growth of O.lagopus is limited by N,suitable nitrogen fertilizer can be applied to restore its growth. |
| Key words: Ochroma lagopus waterlogging stress growth ecological stoichiometry |
