喀斯特地区4种造林幼苗的抗旱性评价
Drought Resistance of Four Species of Tree Saplings for Afforestation in Karst Regions
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摘要: 以杜英、伞花木、侧柏、栾树1年生幼苗为试验材料,通过调控土壤含水量,设置1个无干旱胁迫对照和3个干旱胁迫强度处理(分别为每2、4、6、8d浇水1次),比较4种幼苗叶片相对含水量(RWC),质膜相对透性(RMP),丙二醛(MDA)、游离脯氨酸(Pro)和可溶性糖(SS)含量,过氧化物酶(POD)活性的变化。结果表明,经干旱胁迫后,各供试树种叶片RWC减少,RMP增大,SS、Pro和MDA含量增加,POD活性变化趋势不同。利用隶属函数法对供试树种进行抗旱性综合评价,4个树种的抗旱性强弱为伞花木>侧柏>栾树=杜英。对6个生理生化指标抗旱系数进行相关分析的结果表明,MDA含量、POD活性和Pro含量之间相关性较为紧密。对供试幼苗的测试指标做方差分析,并采用SSR法进行多重比较的结果显示,RMP、MDA含量、POD活性、Pro含量4个指标可用以评价供试树种苗期抗旱性强弱。Abstract: Physiological variation was studied of one-year-old saplings of Elaeocarpus sylvestris,Eurycorymbus cavaleriei,Platycladus orientalis and Koelrenteria paniculata exposed to different levels of drought stress imposed by watering the saplings once every 2(as control),4,6 and 8 days.Effects of the droughts on the saplings were evaluated by monitoring variation of the relative water content(RWC),relative membrane permeability(RMP),contents of malondialdehyde(MDA),free proline(Pro) and soluble sugar(SS),activity of peroxidase(POD) in their leaves.Results show that RWC decreased,and RMP and contents of MDA,free proline and soluble sugar increased with the intensifying drought stress,but POD activity varied differently.Integrated evaluation of the drought resistance of the four saplings was performed with the subordinate function method,revealing a decreasing order in drought resistance of Eurycorymbus cavaleriei > Platycladus orientalis > Koelrenteria paniculata = Elaeocarpus sylvestris.Correlation analysis of the 6 physiological indices of drought resistance indicates that MDA,POD and Pro are closely correlated with each other.Analysis of variance and multi-comparison using the SSR method of the measurements of the saplings show that RMP,MDA content,POD activity and Pro content are useful indicators of drought resistance of the four species of saplings.更多还原