NaCl胁迫对甘薯试管苗生长及离子含量影响

Effect of Sodium Chloride Stress on Growth of Sweet Potato Plantlets in vitro and Ion Content

[目的]探讨甘薯的耐盐机理。[方法]用浓度分别为0、100 mmol/LNaCl处理耐盐性不同的2个甘薯品种徐25-2(耐盐品种)和胜利百号(盐敏感品种),培养20 d后以火焰光度计测定根、茎、叶中的Na+含量、Na+/K+比值,并测不同品种的根、茎、叶的干重、鲜重。[结果]盐胁迫下,2个甘薯品种的生长均受抑制,导致植株矮小、叶片变少、根系稀少、根叶干物质减少,但是徐25-2幼苗受抑制程度较轻;此外,2个甘薯品种不同器官(根、茎、叶)的Na+含量及Na+/K+比值都增加,耐盐性强的徐25-2的Na+含量在根、茎和叶片中较低,而耐盐性较弱的胜利百号幼苗茎、叶Na+含量较高,但徐25-2的变化幅度均小于胜利百号。[结论]盐胁迫下叶片较低的Na+含量和Na+/K+比值是甘薯品种耐盐性的重要特征。

[ Objective ] The aim of this study was to investigate the salt-tolerance mechanism of sweet potato. [ Method ] Two sweet potato varieties of Xu 25-2 （ salt-tolerant eultivar） and Triumph 100 （ salt-sensitive cultivar） were treated by sodium chloride with the concentration of 0 and 100 mmol/L. After 20 days, Na^＋ content and Na^＋/K^＋ ratio in the roots, shoot and leave were determined by the flame photometer, while dry weight and fresh weight of roots, shoot and leave in different varieties were also studied. [ Result] The growth of two sweet potato varieties was inhibited under salt stress, so the plant beeame shorter, leaf and root became fewer, dry weight of roots and leave decreased, but seedlings of Xu 25-2 were inhibited slightly. Furthermore, Na^＋ content and Na ^＋/K ^＋ ratio in roots, shoot and leaves of two sweet potato varieties increased. Na^＋ content of salt-tolerant Xu 25-2 was low in roots, shoot and leaves, while Na ^＋ content of salt-sensitive Triumph 100 was high in shoot and leave of seedlings, but the change range of Xu 25-2 was less than that of Triumph 100. [ Conclusion] The lower Na^ ＋ content and Na^ ＋/K^ ＋ ratio in leaves under salt stress is the most important characteristics for salt-tolerance of sweet potato varieties.