春季辽宁西北部主要绿化树种根叶抗旱生理性状评价

对辽宁西北部主要绿化树种杨树、榆树、丁香和山杏的抗旱生理性状进行研究,分析春季干旱胁迫下4个树种叶片与根系生理性状间的关系,采用隶属函数法和灰色关联度法对其抗旱性进行评价.结果表明: 渗透调节物质可溶性糖、可溶性蛋白和脯氨酸含量、抗氧化酶——超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性,以及丙二醛含量在4个树种及不同器官(叶片与根系)中均存在显著差异.4个树种平均隶属函数值在叶片中的顺序为榆树(0.673)>丁香(0.412)>杨树(0.346)>山杏(0.245),在根系中的顺序为杨树(0.558)>丁香(0.552)>山杏(0.383)>榆树(0.315);杨树、丁香和山杏叶片平均隶属函数值小于根系,而在榆树叶片中大于根系.各项生理指标与抗旱性的关联顺序在叶片中表现为丙二醛>SOD>CAT>可溶性蛋白>脯氨酸>可溶性糖>POD,在根系中为丙二醛>可溶性蛋白>可溶性糖>CAT>POD>脯氨酸>SOD.4个树种的叶片和根系中抗旱能力不同,各抗旱指标在叶片与根系中的作用不同,对不同树种的不同器官应该采取不同的管护措施.

Evaluation of drought-resistant physiological characteristics of roots and leaves for main greening tree species in Northwest Liaoning Province,China in spring.

In the present study, the effects of spring drought stress on physiological characteristics of leaves and roots for Populus alba, Ulmus pumila, Syringa oblata and Prunus sibirica were analyzed in Northwest Liaoning Province. The relationships between leaves and roots under drought stress were explored, and drought resistance of the four tree species was evaluated with the method of subordinate function and the gray correlative analysis. The results showed that there were significant differences in osmotic substances contents (soluble sugar, soluble protein and proline), antioxidative enzymes activities (SOD, POD and CAT) and malondialdehyde content among the four tree species and different organs (leaves and roots) (P<0.05). The average subordinative value in leaves increased in a sequence of P. sibirica (0.245), P. alba (0.346), S. oblata (0.412) and U. pumila (0.673), but it increased in roots in an order of U. pumila (0.315), P. sibirica (0.383), S. oblata (0.552) and P. alba (0.558). Meanwhile, the average subordinative value in leaves of P. alba, S. oblata and P. sibirica was lower than in roots, but it was higher in leaves than in roots of U. pumila. The association between physiological indexes and drought resistance showed an order of malondialdehyde > SOD > CAT > soluble protein > proline > soluble sugar > POD in leaves, and an order of malondialdehyde > soluble protein > soluble sugar > CAT > POD > proline > SOD in roots. These results indicated that the drought-resistant capability was different in leaves and roots of the four tree species. The roles of drought-resistance indexes were different between leaves and roots of the four tree species. Different management measures should be selected according to different organs of various tree species.