茉莉酸甲酯对秦岭高山杜鹃耐热性的影响

为提高高山杜鹃的耐热性,给高山杜鹃的引种栽培提供依据,通过对秦岭高山杜鹃外施植物生长调节剂,测定高温胁迫下不同浓度外源茉莉酸甲酯处理杜鹃幼苗叶片的热害指数,并测定叶片中的超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性、丙二醛(MDA)、脯氨酸含量及质膜透性。结果表明:在高温胁迫下,随着茉莉酸甲酯浓度的增加,SOD、POD及CAT活性及脯氨酸含量呈现先升后降的趋势,且茉莉酸甲酯浓度在100μmol/L时SOD、POD及CAT活性达到最大,分别为107U/g、92U/g和12.74U/g;MDA含量、质膜透性呈先降后升的趋势,茉莉酸甲酯浓度在50μmol/L时质膜透性和MDA含量最小,分别为20%和8.92μg/g。不同浓度的茉莉酸甲酯均能缓解高温对高山杜鹃幼苗的伤害。茉莉酸甲酯浓度为50μmol/L和100μmol/L时对高温胁迫下高山杜鹃各项生理生化特征有较好的缓解作用,可减轻高温对高山杜鹃的热伤害,提高其耐热性。

Effects of Methyl Jasmonic Acid on Tolerance of Rhododendron lapponicum in Qinling to Heat-stress

In order to improve the heat resistance of R.lapponicum,provide.references for the introduction and cultivation of R.lapponicum,The thermotolerance index of R.lapponicum leaves treated with different concentrations of exogenous methyl jasmonate under high temperature stress was measured and the superoxide dismutase (SOD) activity in leaf of R.lapponicum was measured by exogenous plant growth regulator (SOD),peroxidase (POD) and catalase (CAT) activities,malondialdehyde (MDA),proline content and plasma membrane permeability.Results:Activities of SOD,POD,CAT and proline increased first and then decreased with the increasing of methyl jasmonate concentration,and the concentration of methyl jasmonate was 100 μmol/L,the activities of SOD,POD and CAT were the highest,which were 107 U/g,92 U/g and 12.74 U/g,respectively.MDA content and plasma membrane permeability decreased first and then increased,and the concentration of methyl jasmonate was 50 μmol/L and MDA contents reached 20％ and 8.92 μg/g,respectively.Different concentrations of methyl jasmonate could alleviate the damage of alpine seedlings.When the concentration of methyl jasmonate is 50 μmol/L and 100 μmol/L,the physiological and biochemical characteristics of R.lapponicum can be relieved under the high temperature stress,which can reduce heat damage and improve the heat tolerance.