摘要本文用NaCl模拟盐胁迫，采用种子萌发、温室盆栽试验，以与内生菌KLBMP 5084共生培养的中华补血草为材料，通过测定不同盐浓度处理条件下中华补血草的叶长、根长、全株长、鲜重、脯氨酸、超氧化物歧化酶（SOD）活性、过氧化物酶（POD）活性、丙二醛（MDA）和离子含量，分析KLBMP 5084对中华补血草生长的影响，并初步阐释其作用机制。结果显示，盐胁迫下回接内生菌KLBMP 5084能显著促进中华补血草的生长，提高植物体内抗氧化物酶活性，增加游离脯氨酸含量，降低叶片MDA含量，促进Na+ 外排，有效缓解盐胁迫对宿主造成的生长抑制。该内生菌经形态特征与16S rRNA基因序列分析鉴定为链霉菌属中的密旋链霉菌Streptomyces pactum的一个菌株，具有进一步深入研究的价值。41859

该论文有图6幅，表5个，参考文献27篇。

毕业论文关键词： 盐胁迫  内生菌  中华补血草  促生作用与机制

Study on the Plant Growth Promoting Effect of Endophyte KLBMP 5084 Associated with Limonium sinense under Salt Stress and its Preliminary Mechanism

Abstract In this study, the endophytic strain KLBMP 5084 was inoculated to the seeds and plantlets of Limonium sinense which were planted in the pots under salt stress to research the inoculation effects. Leaf and root length, plant fresh weight were recorded, proline, SOD, POD, MDA and Na+ contents were determined to analyze the plant growth promoting effects and related mechanisms. The results revealed that endophytic strain KLBMP 5084 was found to promote the growth of host plant under salt stress. Limonium sinense seedlings grown under saline conditions inoculated with KLBMP 5084 increased levels of proline, SOD and POD, reduced the content of MDA and enhanced elimination of Na+. KLBMP 5084 effectively alleviated the growth inhibition caused by salt stress on the Limonium sinense. This endophyte was identified as the strain of the species Streptomyces pactum, and has further research value.

Key words: salt stress  endophyte  Limonium sinense  plant growth promoting effect and mechanism  

 目  录

摘要 I

Abstract II

目录 III

图清单 V

表清单 V

1 绪论 1

2 材料 2

2.1 供试植物 2

2.2 供试菌株 2

2.3 培养基 2

2.4 主要试验仪器 2

2.5 主要实验试剂 2

3 方法 3

3.1 植物内生菌的分离和培养 3

3.2 菌株KLBMP 5084的鉴定 3

3.3 种子萌发 4

3.4 菌液制备 4

3.5 盆栽试验 4

3.6 植物生长指标的测定 5

3.7 植物生理生化指标的测定 5

4 结果与分析 5

4.1 菌株KLBMP 5084的生理生化特征及其系统发育分析 5

4.2 盐胁迫下KLBMP 5084对中华补血草生长指标的影响 8

4.3 盐胁迫下KLBMP 5084对中华补血草MDA含量的影响 9

4.4 盐胁迫下KLBMP 5084对中华补血草脯氨酸含量的影响