| 摘要: |
| 【目的】研究干旱及复水处理对红背山麻杆生长及生理特性的影响，为防治红背山麻杆灌丛退化以及喀斯特地区乡土树种选育提供理论依据。【方法】以1年生红背山麻杆扦插苗为试验材料，采用盆栽试验，通过自然干燥法，对红背山麻杆进行14，28，42 d干旱胁迫，并对干旱胁迫42 d的植株进行为期5 d的复水处理，以正常供水处理的红背山麻杆为对照组（土壤含水率（24.4±1.23）%），比较干旱与复水条件下红背山麻杆生长指标，叶绿素、丙二醛（MDA）、渗透调节物质（可溶性糖、可溶性蛋白）含量以及抗氧化酶（SOD、CAT、POD）活性的变化情况。【结果】（1）随着干旱胁迫时间的增加，红背山麻杆株高、单叶面积、总生物量总体上均低于对照组，根冠比高于对照组；复水后红背山麻杆单叶面积、总生物量与对照差异不显著，株高显著低于对照组，根冠比仍显著高于对照组。（2）随着干旱胁迫时间的增加，红背山麻杆叶绿素a、b、a+b含量和a/b均先升高后降低，以上指标总体上均高于对照组；与干旱胁迫42 d时相比，复水后以上叶绿素参数均增大，且与对照组差异不显著。（3）干旱胁迫14~42 d时，红背山麻杆叶片和根系MDA、可溶性糖和可溶性蛋白含量以及SOD、POD、CAT活性总体上均高于对照组；与干旱胁迫42 d时相比，复水后红背山麻杆叶片、根系MDA、可溶性糖和可溶性蛋白含量以及SOD、POD、CAT活性均降低，但仍高于对照组。【结论】干旱胁迫与复水对喀斯特地区红背山麻杆生长及生理特性有明显影响;干旱胁迫42 d后复水，红背山麻杆根系的恢复能力优于叶片，可以选育根系较为发达的红背山麻杆品种以适应喀斯特地区恶劣的干旱环境。 |
| 关键词: 喀斯特地区 红背山麻杆 干旱复水 生理特征 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金项目（31800205）；广西自然科学基金项目（2019JJA130069）；广西中青年教师科研基础能力提升项目（2020KY14018）；广西大学生创新创业训练项目（202010606163） |
|
| Effects of drought stress and re-watering on growth and physiology characteristics of Alchornea trewioides in Karst areas |
|
ZHAO Ying,ZHAO Kaili,ZHU Yulin,et al
|
| Abstract: |
| 【Objective】This study investigated the effects of drought and re-watering on growth and physiological characteristics of Alchornea trewioides to provide basis for the prevention and control of Alchornea trewioides degradation and the selection and breeding of native tree species in Karst areas.【Method】One-year-old Alchornea trewioides seedlings in pots were treated with drought stress for 14,28 and 42 days and re-watered for 5 days after 42 days of drought stress.By setting Alchornea trewioides with normal water supply as control (soil moisture content（24.4±1.23)%),the changes in growth indexes,contents of chlorophyll,malondialdehyde (MDA) and osmotic regulatory substances (soluble sugar and soluble protein) and antioxidant enzyme activities (SOD,CAT and POD) in leaves and roots were compared.【Result】(1) With the extension of drought stress time,plant height,leaf area and biomass of Alchornea trewioides decreased,while the root to shoot ratio increased significantly.After re-watering,there were no significant differences in single leaf area and total biomass,plant height was significantly lower than that of the control,while the root to shoot ratio was still significantly higher than that of the control.(2) With the increase of drought stress time,contents of Chla,Chlb and Chl(a+b) and Chl a/b ratio increased first and then decreased,and all were higher than the control.Compared with the 42 d drought stress,chlorophyll parameters increased after re-watering without significant differences.(3) Contents of MDA,soluble sugar and soluble protein and activities of SOD,POD and CAT in Alchornea trewioides leaves and roots were higher than those in control group during 14 to 42 days of drought stress.Compared with 42 days of drought stress,contents of MDA,soluble sugar and soluble protein and activities of SOD,POD and CAT in leaves and roots after re-watering decreased,but all were higher than those in control.【Conclusion】Drought stress and re-watering had significant effects on growth and physiological characteristics of Alchornea trewioides in Karst areas,and the recovery ability of roots after drought stress and re-watering was better than that of leaves.It is suggested to cultivate varieties with developed roots to prevent shrub degradation. |
| Key words: Karst area Alchornea trewioides drought stress and re-watering physiological characteristics |
