3种阔叶树种对持续干旱的生理响应及抗旱性评价

采用盆栽的试验方法,测定持续干旱条件下2年生五角枫、臭椿、黄连木幼苗的丙二醛(MDA)、超氧化物歧化酶(SOD)、细胞膜透性、叶片相对含水量、叶绿素、脯氨酸、光合生理参数,研究其对干旱胁迫的生理响应,并用隶属函数法进行抗旱性评价。结果表明:随干旱程度的加剧,3树种的MDA、细胞膜透性、脯氨酸都呈上升趋势,叶片相对含水量、净光合速率呈降低趋势;五角枫与臭椿叶片的SOD活性呈先升后降的变化趋势,黄连木叶片的SOD活性呈先升后降再升的变化趋势;五角枫与臭椿叶片叶绿素含量先升高后降低,黄连木叶片的叶绿素含量试验前后的变化不大;臭椿与黄连木叶片的水分利用效率呈先降后升再降的变化趋势,五角枫叶片的水分利用效率呈先升后降的变化趋势。经隶属函数法分析得出3树种的抗旱性大小表现为臭椿>黄连木>五角枫。通过灰色关联分析得出脯氨酸、SOD、叶片相对含水量与3树种的抗旱性关系最密切。

Physiological response of three broadleaved tree species to drought stress and evaluation of drought resistance

The two years Acer mono Maxim. , Ailanthus altissima Swingl. and Pistacia chinensis Bunge＇s physiological parameters such as malondialdehyde （MDA）, superoxide dismutase （SOD） activity, cell membrane permeability, leaf relative water content, chlorophyll, proline content, photosynthetic were measured by potting experiment. The physiological response of the three broadleaved tree species to soil drought stress was analyzed, and the drought resistance was evaluated by subordinate function. The results showed that： with the development of drought stress, the MDA, cell membrane permeability and proline content of the three tree species increased, while leaf relative water content and net photosynthetic rate decreased; Acer mono Maxim. and Ailanthus altissima Swingl. ＇ s SOD activity rose at first, and then dropped, while Pistacia chinensis Bunge＇ s SOD activity rose at first and then dropped, at last rose again; Acer mono Maxim. and Ailanthus altissima Swingl. ＇ s chlorophyll content rose at first and then dropped, while Pistacia chinensis Bunge＇ s chlorophyll content had no distinct variation between pretest and posttest. Ailanthus altissima Swingl. and Pistacia chinensis Bunge＇ s water use efficiency of leaf dropped at first and then rose ,at last dropped again, while Acer mono Maxim. ＇ s water use efficiency of leaf rose at first, and then dropped. The subordinate function was used to rank their drought tolerance, and the order was： Ailanthus altissima Swingl. 〉 Pistacia chinensis Bunge 〉 Acer mono Maxim.. We knew proline, SOD and leaf relative water content were the key indicators to evaluate the drought resistance of the three tree species by grey correlation analysis.