| 摘要: |
| 【目的】分析干旱胁迫对香柏幼苗生理指标、光合指标及抗氧化酶活性的影响，寻求香柏幼苗生长的理想水分条件，探讨香柏幼苗生长对水分变化的适应机理。【方法】以香柏3年生扦插苗为试验材料，通过盆栽试验，设置正常供水（土壤含水量为田间持水量的90%～95%）、轻度干旱胁迫（土壤含水量为田间持水量的70%～75%）、中度干旱胁迫（土壤含水量为田间持水量的50%～55%）、重度干旱胁迫（土壤含水量为田间持水量的30%～35%）4个处理，研究干旱胁迫对香柏幼苗生长、光合作用及各项生理指标的影响。【结果】干旱胁迫对香柏幼苗地径、根质量、茎叶质量、总生物量、根质量比、茎叶质量比、根长等有显著影响，但对株高影响不显著。4个干旱胁迫处理下香柏幼苗的净光合速率、蒸腾速率、水分利用效率表现出基本一致的变化趋势，即均在轻度干旱胁迫处理下达到最大值。与正常供水相比，干旱胁迫使香柏幼苗叶绿素含量明显增加。轻度干旱胁迫条件下，香柏幼苗叶片丙二醛浓度明显低于其他3个处理。超氧化物歧化酶、过氧化物酶活性及可溶性糖含量均在轻度干旱胁迫时达到最大。干旱胁迫条件下香柏叶片可溶性蛋白质含量降低，且以轻度干旱胁迫下的叶片可溶性蛋白质含量最低。【结论】香柏幼苗不适宜在土壤过于干旱或湿润的环境下生长，而适于在轻度干旱即土壤含水量为田间持水量70%～75%的条件下生长。 |
| 关键词: 香柏 干旱胁迫 生长 光合及生理 |
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| 基金项目:国家科技支撑计划项目（2013BAC04B01）；国家自然科学基金项目（31460192）；西藏大学农牧学院林学特色专业建设项目 |
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| Effect of drought stress on growth and physiological indicators of Sabina pingii var.wilsonii seedlings |
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LUOSANG Zhuo-ma,XIN Fu-mei,YANG Xiao-lin,et al
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| Abstract: |
| 【Objective】By analyzing the effects of drought stress on physiological indicators,light indicators and antioxidant enzyme activities of cedar seedlings,this study aimed to find the ideal water conditions for growth of Sabina pingii var.wilsonii seedling and investigate its adaptation mechanism to water impacts.【Method】Using 3-year-old cuttings as test material,the differences in growth,photosynthesis and physiological indicators of Sabina pingii var.wilsonii were studied.【Result】Different water conditions significantly affected the basal diameter,root weight,leaf weight,total biomass,root weight ratio,leaf weight ratio,and root length of cedar seedlings except for height.Under different water conditions,the net photosynthetic rate,transpiration rate,water use efficiency of Sabina pingii var.wilsonii seedlings showed consistent trend in general with the maximum values of indicators under light drought.Drought stress increased the chlorophyll content of seedlings.Under light drought the MDA content was significantly lower than the other three water conditions while SOD,POD and soluble sugar contents were the maximum.Under drought stress the soluble protein content decreased and the minimum content occurred under light drought.【Conclusion】Too dry or wet environments were not suitable for Sabina pingii var.wilsonii seedlings while light drought (soil water content was 70%-75% of field water capacity) was the most conducive. |
| Key words: Sabina pingii var.wilsonii drought stress growth photosynthetic and physiological |
