干旱胁迫下不同种源文冠果幼苗的生理反应及其抗旱性分析

Effects of Drought Stress on Physiological Characteristics of Xanthoceras sorbifolia from Different Provenances and Analysis on Drought-resistance in Seedling Stage

以5个种源的2年生文冠果幼苗为参试材料,在盆栽条件下测定其在不同水分梯度条件下叶片的保护酶(SOD、CAT)活性、脯氨酸(Pro)含量、可溶性糖(SS)含量、丙二醛(MDA)含量、可溶性蛋白(SP)、叶绿素(Chl)含量等生理指标;并利用隶属函数法对其进行抗旱性的综合评价。结果表明:随着干旱胁迫程度的不断增大,5个不同种源文冠果叶片的叶绿素含量、净光合速率(Pn)、气孔导度(Cond)呈逐渐降低的趋势;脯氨酸、丙二醛、可溶性总糖和可溶性蛋白含量则呈现逐渐增加的趋势;SOD、CAT呈现先上升后下降的趋势。各种指标变化幅度因文冠果种源不同而不同。根据抗旱隶属函数值的比较,得出不同种源文冠果的抗旱能力大小依次为:新疆>甘肃>内蒙古>青海>陕北。

The drought-resistance of 5varieties of Xanthocerassorbifoliafrom 5provenances was studied under the simulated drought conditions.Physiological indexes were measured,such as the activities of superoxide dismutase and catalase,the content of proline,soluble sugar,soluble protein,malondialdehyde and chlorophyll in the leaves.The comprehensive evaluation on drought resistance was conducted by subordinate function.The results showed that the chlorophyll content,stomatal conductance and net photosynthesis rate decreased with the decrease of soil relative water content.The content of proline,malondialdehyde, soluble sugar and soluble protein decreased when the soil relative water content decreased.The activities of superoxide dismutase and catalase increased firstly,and then decreased in the same condition.The changes of the physiological indexes in different varieties showed different ranges.By subordinate function analysis, it was concluded that the drought-resistance of 5varieties decreased in the order of Kashi,Xinjiang Jingyuan,GansuChifeng,Inner MongoliaXunhua,QinghaiYan′an,Shaanxi.