3种园林植物幼苗对旱涝胁迫的生理响应及综合评价

Physiological Response and Comprehensive Evaluated on 3 Species of Landscape Tree Seedlings Subjected to Soil Drought and Waterlogging

通过测定阴香、山杜英、铁冬青幼苗在干旱、水涝及旱涝交替环境下的8项生理指标,运用模糊隶属函数法系统评价3种园林植物幼苗的抗水分胁迫能力,分析其对水分胁迫的生理响应机制和抗逆性。结果表明:淹水胁迫下,铁冬青的丙二醛含量降低,超氧化物歧化酶活性小幅下降,受涝害程度轻。干旱胁迫下,山杜英和铁冬青丙二醛含量升高,超氧化物歧化酶活性和水分利用效率显著下降,受害较重;而阴香的丙二醛含量和超氧化物歧化酶活性小幅下降,受害最轻。旱涝交替胁迫下,3者可溶性蛋白含量增加,超氧化物歧化酶活性、气孔导度和蒸腾速率显著下降。3种幼苗通过增加可溶性蛋白含量提高渗透调节能力,以应对水分胁迫,且在干旱和旱涝交替胁迫中还采取关闭气孔减少水分蒸散,维持较高水分利用效率的适应性策略。

This paper disposed of Cinnamomum burmannii,Elaeocarpus sylvestris and Ilex rotunda seedlings in drought,waterlogging and drought-waterlogging soil conditions,8 physiological indexes of each species were determined.Based on the fuzzy membership function,water stress resistance and physiological response of the 3 species of landscape tree seedlings was explored.The results showed that in waterlogging treatment,the malondialdehyde increment of I.rotunda decreased and its superoxide dismutase actiity reduced slightly,with mild waterlogging injury.In drought treatment,malondialdehyde of E.sylvestris and I.rotunda increased,superoxide dismutase activity and water use efficiency decreased significantly,these indicated E.sylvestris and I.rotunda had more serious damage by drought,whereas the malondialdehyde and superoxide dismutase activity of C.burmannii decreased slightly,showed that C.burmannii had the slightest injury degree.In drought-waterlogging treatment,the soluble protein content of 3 seedlings increased while superoxide dismutase activity,stomatal conductance and transpiration rate decreased significantly.These 3 seedlings could enhance osmotic adjustment ability by increasing soluble protein content so as to cope with water stress.In continuous drought and flood-drought treatment,seedlings reduced transpiration by closing the stomata to maintained higher water use efficiency.