褪黑素预处理对水稻耐盐性的影响
时间:2018-08-26 19:51 来源:毕业论文 作者:毕业论文 点击:次
| 摘要：本文以两种水稻品种（辽粳4号和日本晴）为研究材料，进行了不同浓度褪黑素（MT）溶液浸种对盐胁迫下种子发芽率和发芽质量，以及不同浓度MT溶液预处理（含整个种子发芽期和育苗期）对水稻植株耐盐性的影响及其机制的研究。结果表明：在种子发芽期，120 mM NaCl外加不同浓度（10500μM）MT溶液处理后，辽粳4号和日本晴种子的发芽势、发芽指数和活力指数等均明显恢复。在幼苗期，经MT溶液预处理后的水稻植株根和叶盐害症状（由相对电导率体现）明显减轻，植株生长得以恢复，可能主要是通过提高种子发芽质量（由发芽势、发芽指数和活力指数等指标体现），增强根系活力，增强根和叶片抗氧化酶（如CAT和SOD）活性以降低活性氧含量等多种生理机制协调实现。MT为一种胺类激素，无毒无害，浸种和幼苗根施时用量少，操作简单，短期内可明显提高盐胁迫下水稻种子发芽和幼苗质量，能有效解决水稻在盐渍土壤中发芽率低和幼苗活力差的问题，为水稻乃至其它作物的耐盐育种、化学调控和盐渍地区种植实践提供了理论依据和技术支撑。27423 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 (责任编辑：qin) |