3个种源池杉幼苗对干旱胁迫的生理响应及抗旱性评价

Physiological Response to Drought Stress and Drought Resistance Evaluation of Taxodium distichum var.imbricatum(Nuttall)Croom Seedlings from Three Provenances

本试验探究不同种源池杉幼苗的抗旱性差异,以期为其引种驯化、抗旱种源筛选与培育、消落带植被选择及池杉抗旱性育种提供一定的参考。利用不同浓度PEG-6000与Hoagland的混合液模拟不同程度干旱胁迫,测定干旱胁迫对3个种源池杉幼苗渗透调节物质和抗氧化特性的影响,并利用抗旱指数与主成分分析、隶属函数相结合的方法对其抗旱性进行综合评价。结果表明:3个种源池杉幼苗的丙二醛、可溶性糖、可溶性蛋白含量以及超氧化物歧化酶和抗坏血酸过氧化物酶活性均随着干旱胁迫程度的增大而逐渐升高;浙江安吉和江西分宜种源的叶绿素a、b及总含量均随着干旱胁迫程度的增大而逐渐升高,而广西凭祥种源的含量则呈先下降再上升的趋势;浙江安吉和广西凭祥种源的过氧化物酶活性随着干旱胁迫程度的增大而逐渐升高,而江西分宜种源的则呈先上升再下降的趋势。经综合评价,3个种源池杉幼苗的抗旱性强弱表现为浙江安吉>江西分宜>广西凭祥。

This research explored the drought resistance differences of Taxodium distichum var.imbricatum(Nuttall)Croom seedlings from different provenances in order to provide some references for its introduction and domestication,drought resistant provenance screening and cultivation,vegetation plant selection in fluctuating zone and drought resistant breeding.Different concentrations of PEG-6000 and Hoagland mixture were used to simulate drought stress,and their effects on osmotic adjustment substances contents and antioxidant characteristics of T.distichum var.imbricatum seedlings from three provenances were determined.Their drought resistance were comprehensively evaluated by the combination of drought resistance index,principal component analysis and membership function methods.The results showed that the contents of malondialdehyde,soluble sugar,soluble protein and activities of superoxide dismutase and ascorbate peroxidase in the seedlings from the three provenances increased gradually with the increase of drought stress,and the chlorophyll a,chlorophyll b and chlorophyll a+b contents of ZJAJ and JXFY increased gradually with the increase of drought stress,while those of GXPX decreased first and then increased.The peroxidase activity of ZJAJ and GXPX increased gradually with the increase of drought stress,while that of JXFY increased first and then decreased.After comprehensive evaluation,it was concluded that the order of drought resistance of T.distichum var.imbricatum seedlings from the three provenances was ZJAJ>JXFY>GXPX.