CAJ | 학술논문

以两个耐热性不同的萝卜品种为试材，研究高温胁迫对萝卜幼苗叶片电解质渗漏率（EL）、丙二醛（MDA）含量、渗透调节物质及抗氧化酶活性等生理指标的影响。结果表明，高温胁迫后，两萝卜品种叶片EL和MDA含量均逐渐升高，但耐热品种夏米岛（XD）升高幅度低于感热品种乌兹别克冬萝卜（WD）；高温胁迫前，XD幼苗叶片可溶性糖与脯氨酸（Pro）含量均高于WD，而高温胁迫后，两品种可溶性糖和Pro含量均逐渐升高，但XD叶片中两者含量显著高于WD；高温胁迫下，XD通过大幅升高SOD活性来消除O2-的伤害，而WD通过大幅度升高POD和APX活性，以清除体内的H2O2，防止活性氧伤害，说明耐热性不同萝卜品种对高温胁迫造成的活性氧伤害的清除机理不同。恢复4 d后，XD叶片中EL和MDA含量基本恢复至处理前水平，WD显著高于处理前；两品种中可溶性糖和Pro含量差异不显著；抗氧化酶活性变化差异较大。可见，耐热品种XD本身含有较高的渗透调节物质可溶性糖和Pro，从而通过降低EL和MDA含量及提高SOD活性来减轻高温热害。
이량개내열성불동적라복품충위시재，연구고온협박대라복유묘협편전해질삼루솔（EL）、병이철（MDA）함량、삼투조절물질급항양화매활성등생리지표적영향。결과표명，고온협박후，량라복품충협편EL화MDA함량균축점승고，단내열품충하미도（XD）승고폭도저우감열품충오자별극동라복（WD）；고온협박전，XD유묘협편가용성당여포안산（Pro）함량균고우WD，이고온협박후，량품충가용성당화Pro함량균축점승고，단XD협편중량자함량현저고우WD；고온협박하，XD통과대폭승고SOD활성래소제O2-적상해，이WD통과대폭도승고POD화APX활성，이청제체내적H2O2，방지활성양상해，설명내열성불동라복품충대고온협박조성적활성양상해적청제궤리불동。회복4 d후，XD협편중EL화MDA함량기본회복지처리전수평，WD현저고우처리전；량품충중가용성당화Pro함량차이불현저；항양화매활성변화차이교대。가견，내열품충XD본신함유교고적삼투조절물질가용성당화Pro，종이통과강저EL화MDA함량급제고SOD활성래감경고온열해。
The effects of high temperature stress on the physiological indexes such as the electrol-yte leakage (EL), the content of MDA, osmotic adjustment materials and antioxidant enzyme activities in leaves of radish seedlings were investigated, taking two radish varieties of different heat tolerance as test materials. The results showed that after high temperature stress, EL and the content of MDA were up-regulated in both two radish cultivars, and the values in heat-tolerant cultivar Xiamidao (XD) were improved in a lower range than those of heat-sensitive cultivar Wuzibieke dong luo bo (WD). The contents of soluble sugar and proline were also increased and the change in XD was remarkably higher than WD under high temperature, while the contents of soluble sugar and proline in XD were higher than WD. The SOD activity in XD was improved in a high range to eliminate the hurt from O2-·, while in WD, the activities of POD and APX were all improved in a high range to clear away H2O2 of itself and prevent active oxygen hurt. This showed that the elimination mechanisms of active oxygen hurt in different heat tolerance radish cultivars are different. After recovery treat for 4 d, EL and the content of MDA in XD mainly had come to primary levels, while in WD, they were significantly higher than those before the treat of high temperature stress. The contents of soluble sugar and proline exhibited no significant difference in both two radish cultivars. However, the activities of antioxidant enzyme had bigger difference. These results indicated that the heat-tolerant cultivar XD has strong ability to maintain the relative stability of membrane system and the membrane integrity, in addition, XD has a lower degree of membrane lipid peroxide. It is clear that the breed of XD, which is heat-resistant, contains higher osmotic adjustment materials, such as soluble sugar and proline. These results indicate that XD could mitigate the injuries caused by high temperature stress by reducing electrolyte leakage and MDA content and promoting the activity of SOD.