| 摘要: |
| 【目的】探讨Ca(NO3)2胁迫下γ-氨基丁酸（GABA）的浓度效应，为科学合理地应用GABA、提高其综合效益提供理论依据。【方法】选择盐敏感的甜瓜品种“一品天下208”为试验材料，采用1/2山崎甜瓜营养液水培法，设营养液内含80 mmol/L Ca(NO3)2胁迫条件下每天叶面喷施0，10，25，50和75 mmol/L GABA及胁迫前48 h预先叶面喷施25和50 mmol/L GABA 7个处理，以营养液栽培为对照(CK)，比较各处理对甜瓜幼苗生长和生理指标的影响。【结果】Ca(NO3)2胁迫下，甜瓜叶片光合色素、脯氨酸（Pro）和丙二醛（MDA）含量显著升高，幼苗叶面积、干鲜质量、根体积、根表面积、总根长、根尖数和可溶性蛋白（Pr）含量显著降低，甜瓜幼苗的生长受到显著抑制。Ca(NO3)2胁迫下，甜瓜叶片光合色素、Pro和MDA含量随着外源GABA浓度的增加先降低后升高，并且在50 mmol/L 时达到最小值；Pr含量随外源喷施GABA浓度的增加而先升高后降低，在50 mmol/L时达到最大值；外源喷施50 mmol/L GABA处理与单纯Ca(NO3)2处理相比，可明显增加幼苗叶面积、干鲜质量、根体积、根表面积、总根长和根尖数，缓解Ca(NO3)2胁迫对甜瓜幼苗生长的抑制。另外，相同GABA浓度相比，Ca(NO3)2胁迫后喷施较胁迫前预喷施效果好。【结论】叶面喷施50 mmol/L GABA有利于提高幼苗对Ca(NO3)2盐胁迫逆境的适应能力。 |
| 关键词: γ-氨基丁酸 Ca(NO3)2胁迫 甜瓜 生长指标 生理指标 |
| DOI： |
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| 基金项目:国家“十二五”科技支撑计划项目（2011BAD29B01）；西北农林科技大学基本科研业务费（QN2013018） |
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| Effects of GABA on tolerance of muskmelon seedlings against Ca(NO3)2 stress |
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XU Zhi-ran,ZHANG Li,ZHANG Zhi,et al
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| Abstract: |
| 【Objective】The effects of γ-aminobutyric acid (GABA) with different concentrations on tolerance of muskmelon seedlings against Ca(NO3)2 stress were studied to provide theoretical basis for improving GABA application and comprehensive benefits.【Method】Seedlings of salt sensitive cultivar muskmelon（Cucumis melo L.cv.,‘Yipintianxia 208’） were selected for hydroponic cultivation with 1/2 Japan Yamazaki melon special nutrient solution.GABA with different concentrations (0,10,25,50 and 75 mmol/L) were sprayed under 80 mmol/L Ca(NO3)2 stress in the solution.Two other treatments were setup by pre-spraying 25 and 50 mmol/L GABA 48 h before Ca(NO3)2 stress.Then the effects on growth and physiological indexes of seedlings were studied.【Result】Under Ca(NO3)2 stress,contents of photosynthetic pigments,proline and MDA significantly increased,while the leaf area,fresh and dry weight,root volume,root surface area,total root length,tips of root and content of soluble protein significantly reduced.Ca(NO3)2 stress inhibited the growth of muskmelon seedlings.With the increase of exogenous GABA concentration,the contents of photosynthetic pigments,proline and MDA decreased first and then increased,and the minimum values were obtained at the concentration of 50 mmol/L.The content of soluble protein increased first and declined finally by spraying GABA with the maximum obtained at the concentration of 50 mmol/L.Compared with the control,the leaf area,fresh and dry weight,root volume,root surface area,total root length and tips of root increased by spraying 50 mmol/L GABA,which also alleviated the inhibition of Ca(NO3)2.In addition,spraying GABA after Ca(NO3)2 stress was better than pre-spraying at the same concentration.【Conclusion】Foliage spraying of 50 mmol/L GABA effectively improved the tolerance of muskmelon seedlings against Ca(NO3)2 stress. |
| Key words: GABA Ca(NO3)2 stress muskmelon growth indexes physiological indexes |
