褪黑素预处理对水稻耐盐性的影响
毕业论文关键词：盐胁迫；褪黑素；水稻；耐盐机制
Effects of Melatonin Pretreatment on Salt Tolerance of Rice
Abstract： In this paper, the effects of seed soaking with different concentrations of melatonin (MT) solutions on seed germination and germination quality under salt stress and the effects of MT pretreatment (including seed germination period and seedling stage) with different concentrations on salt tolerance of rice plants were studied in two rice cultivars (Oryza sativa L. ssp. japonica Liaojing 4 and Nipponbare). The results showed that, the seed germination potential, germination index and vigor index of Liaojing 4 and Nipponbare were significantly restored after 120mM NaCl treatment with different concentrations (10~500μM) MT solution. At the seedling stage, the plant root and leaf salt symptoms (shown by the relative conductivity) of the rice plant pretreated with MT solution were significantly reduced, and the plant growth was restored, possibly by increasing the seed germination quality (shown by germination potential, germination index and vigor index), and enhancing root activity and antioxidant enzymes (such as CAT and SOD) activities in roots and leaves to reduce the contents of reactive oxygen species. MT is a non-toxic harmless amine hormone, seed soaking and root application with less dosage is a simple operation, and can in short-term significantly improve the salt seed germination and seedling quality, and also can effectively solve the low germination rate and poor seedling efficiency of the rice in saline soil, which provides the theoretical basis and technical support for salt tolerance breeding of rice and other crops, chemical regulation and planting practice in salted areas.
Key words: Salt stress; Melatonin; Rice; Salt tolerance mechanism
目 录
摘要3
关键词3
Abstract3
Key words3
引言3
1材料与方法4
1.1实验材料 4
1.2实验设计 4
1.3测定方法 5
1.3.1种子发芽期5
1.3.2幼苗期5
1.3.2.1根系活力测定5
1.3.2.2 相对电解质渗漏率测定5
1.3.2.3 H2O2含量测定5
1.3.2.4 SOD和CAT活性测定5
1.4数据处理及分析5
2结果6
2.1盐胁迫下褪黑素处理对日本晴和辽粳4号种子发芽形态指标的影响6
2.2盐胁迫下褪黑素处理对日本晴和辽粳4号种子发芽参数的影响6
2.3盐胁迫下褪黑素预处理对日本晴和辽粳4号幼苗鲜重、根系活力、叶相对电解质渗漏率和叶丙二醛含量的影响7
2.4盐胁迫下褪黑素预处理对日本晴和辽粳4号幼苗叶片和根中H2O2含量、CAT活性、SOD活性的影响8
3讨论 9
3.1 褪黑素处理对盐胁迫下水稻种子发芽的效应9