苜蓿根际促生菌的分离、筛选及鉴定
苜蓿根际促生菌的分离、筛选及鉴定(任务书,开题报告,论文10500字)
摘要
近年来我国畜牧业发展迅速，对饲料的需求量日渐增大，进口苜蓿饲料对国内苜蓿产业带来了很大的负面影响，为了增强自身竞争力，就需要在苜蓿品质等方面争取优势，研究苜蓿根际促生菌对苜蓿增产有重要意义。
本文研究用饥饿培养的方法从苜蓿根际中筛选促生菌，先富集菌株，后又用含高氨氮的培养基分离，纯化，筛选，接着进一步研究菌株的生理代谢，即植物生长素的分泌能力测定、溶磷性能测定等，以及对该菌株进行表观观察鉴定和测序鉴定。
结果表明筛选出的菌株中有三株生理生化性能比较突出，分别是N2、Z7、F16。其中F16分泌植物生长素能力最为突出，N2和Z7稍低，但是都比实验其它待测菌株要强。溶磷实验结果表明，Z7的溶磷能力最强，F16溶磷能力稍次，N2的数据明显比空白组小，排除实验误差，表明N2没有溶磷能力，或者溶磷能力很差，于是利用培养基里已有的可用磷用于细菌生长。进一步进行革兰氏染色和芽孢染色，N2是G+且有芽孢，Z7是G-没有芽孢，F16是G-没有芽孢。最后进行16s DNA水平鉴定，PCR后电泳图条带明亮清晰，送样检测结果表明N2是枯草芽孢杆菌（Bacillus subtilis strain )，F16是类芽孢杆菌属（Paenibacillus glycanilyticus strain spp）,Z7是肠杆菌属（Enterobacter spp)。 [资料来源：http://Doc163.com]
关键词：促生菌 IAA 16s DNA
Abstract
In recent years, China's animal husbandry has developed rapidly, and the demand for feed has been increasing day by day. Imports and feeds have had a large negative impact on the domestic waste industry. In order to enhance its competitiveness, it is necessary to strive for advantages in quality and other aspects. The rhizosphere growth-promoting bacteria are of great significance to the production of earthworms.
In this paper, we used the method of hunger culture to screen the growth-promoting bacteria from the rhizosphere of the alfalfa, first enrich the strains, and then use the medium containing high ammonia nitrogen to separate, purify, and screen, and then further study the physiological and biochemical characteristics of the strains, namely auxin. The determination of the secretory capacity, the determination of the phosphorus-solubility properties, and the observation and identification of the strain and its sequencing identification. [资料来源：www.doc163.com]
The results showed that among the selected strains, there were three strains with prominent physiological and biochemical properties, namely N2, Z7 and F16. Among them, F16 has the most prominent ability to secrete auxin, and N2 and Z7 are slightly lower, but they are stronger than other tested strains. Phosphorus dissolution experiment results show that Z7 has the strongest P-dissolving ability, F16 has a slightly lower P-dissolving ability, and the N2 data is obviously smaller than the blank group, excluding the experimental error, indicating that N2 has no P-solubilizing ability or poor P-solubilizing. Therefore, the use of available phosphorus in the medium for bacterial growth. Gram staining and spore staining were further performed. N2 was G+ and spores, Z7 was G- no spores, F16 was G- no spores. Finally, the 16s DNA level was identified and the electrophoretogram bands were bright and clear after PCR.The results of sample delivery test indicated that N2 is Bacillus subtilis strain, F16 is Paenibacillus glycanilyticus strain spp, and Z7 is Enterobacter spp. [资料来源：https://www.doc163.com]
Keywords:Promoting bacteria；IAA；16s DNA
目录
摘要 I
Abstract II
目录 III
第一章 文献综述 1
1.1. 研究背景 1
1.1.1. 研究项目的意义 1
1.1.2. 国内外研究状况 2
1.1.3. PGPR 的概念与种类 2
1.1.4. PGPR 的作用机理 3
1.1.5. PGPR 的应用 5
第二章 实验部分 7
2.1. 培养基 7
2.2. 方法与步骤 8
[资料来源：http://doc163.com]
2.2.1. 促生菌的富集与分离 8
2.2.2. 16 sDNA 水平鉴定 8
2.2.3. 分泌植物生长素测定 10
2.2.4. 溶磷性测试 10
2.2.5. 菌体形态学观察 11
第三章 结果与讨论 13
3.1. 数据分析 13
3.1.1. 16s DNA 水平鉴定结果 13
3.1.2. 植物生长素测定结果 14
3.1.3. 溶磷性测试结果 15
3.1.4. 菌体形态学观察结果 17
3.2. 结果讨论 19
第四章 展望 20
致谢 21
参考文献 22 [版权所有：http://DOC163.com]