| 摘要: |
| 【目的】研究风沙流胁迫对霸王幼苗生理特征的影响，阐述霸王幼苗耐受风沙流胁迫的能力及其阈值，为揭示霸王幼苗遭受风沙流胁迫致死机理提供理论依据。【方法】以霸王1年生盆栽幼苗为试验材料，在风沙环境风洞中模拟风沙流胁迫条件，以风速表示胁迫程度，即分别在0，8，11和14 m/s风速条件下吹袭20 min，依次表示对照、轻度、中度和重度风沙流胁迫处理，研究风沙流胁迫对霸王幼苗叶片叶绿素以及丙二醛含量、抗氧化酶活性、渗透调节物质可溶性糖和脯氨酸含量的影响。【结果】在轻度和中度风沙流胁迫条件下，霸王叶片的抗坏血酸过氧化物酶（APX）和过氧化物酶（POD）活性随胁迫程度的增强呈升高趋势，超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性以及可溶性糖和脯氨酸含量变化不明显，叶绿素含量降低，丙二醛含量升高；在重度风沙流胁迫条件下，霸王叶片APX和POD活性均有不同程度减弱，而SOD和CAT活性略有增强，可溶性糖、脯氨酸和叶绿素含量升高，丙二醛含量降低。【结论】轻度和中度风沙流胁迫使霸王幼苗受到一定程度损伤，但未引起渗透胁迫，APX和POD通过清除活性氧，降低了风沙流胁迫对霸王幼苗的氧化损害；重度风沙流胁迫使霸王幼苗受到严重损伤，引发SOD和CAT活性增强，可溶性糖和脯氨酸含量增大，细胞液外流，渗透胁迫严重，最终使幼苗干枯死亡。 |
| 关键词: 霸王幼苗 风沙流胁迫 生理特征 荒漠植物 |
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| 基金项目:国家自然科学基金项目（31460224，31760244）；甘肃省基础研究创新群体项目（1506RJIA155） |
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| Effects of wind-drift sand on physiological characteristics of Zygophyllum xanthoxylum seedlings |
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LI Daoming,JI Yongfu,ZHANG Yinghua,et al
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| Abstract: |
| 【Objective】This study investigated the ability and threshold value of Zygophyllum xanthoxylum seedlings to resist wind drift sand by studying the effects of wind drift sand on the physiological characteristics to provide theoretical basis for revealing death mechanism of seedlings during wind-drift sand.【Method】The variations of chlorophyll and malondialdehyde contents,antioxidant enzyme activities and contents of osmotic adjustment substance,soluble sugar and proline in leaves of one year old seedlings were analyzed.The contrast,slight,moderate and severe wind-drift sand conditions were simulated in wind tunnel for 20 minutes with wind speeds of 0,8,11 and 14 m/s,respectively.【Result】Under slight or moderate wind-drift sand stresses,APX and POD activities increased gradually while activities of SOD and CAT as well as contents of soluble sugar and proline changed insignificantly.With the increase of wind speed,chlorophyll content decreased while malondialdehyde content increased.However,under severe wind-drift sand stress,APX and POD activities decreased while SOD and CAT activities increased.The contents of soluble sugar,proline and chlorophyll increased and malondialdehyde content decreased.【Conclusion】Slight or moderate wind-drift sand stress damaged the seedlings but did not lead to osmotic stress.APX and POD reduced oxidative damage to seedlings by removing reactive oxygen species.Severe wind-drift sand stress damaged the seedlings seriously,causing increase of SOD and CAT activities and contents of soluble sugar and proline,leak of cytochylema and aggravation of osmotic stress,which would lead to seedling death. |
| Key words: Zygophyllum xanthoxylum seedlings wind drift sand stress physiological characteristics desert plants |
