外源脯氨酸对NaCl胁迫下甜瓜幼苗生长和活性氧物质代谢的影响

摘要

采用营养液水培,研究了不同浓度的外源脯氨酸对100 mmol/L NaCl胁迫下甜瓜幼苗生长、叶绿素含量及活性氧物质含量的影响.结果表明,施用0.1～0.4 mmol/L脯氨酸能显著缓解NaCl胁迫对甜瓜幼苗的伤害,与不添加脯氨酸的NaCl胁迫处理相比,可提高幼苗的鲜重和干重,增加叶片的叶绿素含量,降低叶片过氧化氢(H2O2)含量、超氧阴离子(O·-2)产生速率、丙二醛(MDA)含量和相对电导率,其中以0.20 mmol/L脯氨酸处理效果最好;脯氨酸浓度在0.80～3.20 mmol/L时加重了盐胁迫对甜瓜幼苗的伤害.%Effects of exogenous proline on growth, chlorophyll content and metabolism of reactive oxygen substance of melon seedlings under NaCI stress using nutrient solution hydroponics were studied. The results showed that the proline at the concentration of 0. 10-0. 40 mmol/L remarkably alleviated the damage of NaCI stress to melon seedlings. Compared with the treatment of no proline under NaCI stress, 0. 10-0. 40 mmol/L exogenous proline remarkably increased the fresh and dry weight of seedlings, chlorophyll content in leaves, and decreased the H2O2content, O2- production rate, MDA content and electrolyte leakage in roots. Among those treatments, 0. 20 mmol/L exogenous proline got the best protective effect. However, high proline concentrations of 0.80-3. 20 mmol/L resulted in aggravated damage to the seedlings under salt stress.