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- 2019
黄栌幼苗在持续干旱胁迫环境中的表型适应对策
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Abstract:
以1年生黄栌（Cotinus coggygria）播种苗为供试材料进行控制土壤水分梯度的大田模拟试验，设置3个水分处理水平，探讨黄栌幼苗形态及生长性状和资源利用与分配性状在持续干旱胁迫环境中的适应对策。结果表明，随着土壤水分含量的降低，叶片数量、叶片厚度、茎长度和茎体积均呈显著下降趋势，而根系表面积、根系体积和根系平均直径则均显著增加；干旱显著降低了幼苗的比叶面积、叶片面积比例、茎生物量比例、叶根生物量比和茎根生物量比，而比茎长、根冠比、比根表面积、根表面积比例、根叶面积比例和根生物量比例则随着干旱程度的加剧显著上升。主成分分析表明，根系形态结构的发达程度及对根茎叶的资源配置是决定黄栌适应干旱逆境对策的重要方面，根系表面积、根系体积、根系直径、比根表面积、根系表面积比例和根叶面积比例是衡量黄栌苗木适应干旱生态对策的重要指标。研究结果可为华北地区应对未来干旱气候选择耐旱造林材料提供理论参考。
One-year-old Cotinus coggygria seedlings were used as the test materials to carry out a simulating field experiment in controlling soil moisture gradients.Three water regimes were set to investigate the adaptive strategies of the traits related with morphology,growth,resource utilization and allocation of C.coggygria seedlings in continuous drought environments.The results indicated that the leaf number,leaf thickness,stem length and stem volume decreased significantly as the soil water content dropped,while the root surface area,root volume and root diameter increased significantly.Drought treatments significantly inhibited the specific leaf area,leaf area ratio,stem biomass fraction,leaf-root biomass ratio and stem-root biomass ratio,while significantly promoted the specific stem length,shoot-root ratio,specific root surface area,root surface area ratio,root-leaf area ratio and root biomass fraction.The principle component analysis demonstrated that the development level of root morphology and the resource allocation to leaf,stem and root were two important components in C.coggygria seedlings’ adaption to drought.And the root surface area,root volume,root diameter,specific root surface area,root surface area ratio and root-leaf area ratio were significant parameters to estimate the ecological strategy of C.coggygria seedlings to survive in drought stress.The study provided theoretical reference for screening drought-resistant materials for afforestation in Northern China in the background of future drought climate scenario
