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| 文冠果一、二年生植株根系内生菌的分离、鉴定和固氮活性 | |
| 引用本文： | 张烨,廖怡,陈尚武,马会勤. 文冠果一、二年生植株根系内生菌的分离、鉴定和固氮活性[J]. 植物生态学报, 2010, 34(7): 839-844. DOI: 10.3773/j.issn.1005-264x.2010.07.009 |
| 作者姓名： | 张烨 廖怡 陈尚武 马会勤 |
| 作者单位： | 中国农业大学农学与生物技术学院, 北京 100193 中国农业大学食品科学与营养工程学院, 北京 100083 |
| 基金项目： | 国家高技术研究发展计划(863) |
| 摘 要： | 该文对文冠果(Xanthoceras sorbifolia)根系内生菌的种类和固氮活性进行了首次报道。试验以田间栽培的文冠果一、二年生植株为材料, 以Ashby和YMA为培养基, 对根系内生菌进行了分离, 通过对菌落形态的观察, 划线挑取单菌落培养, 并对7个代表性的单菌落进行扩大培养, 提取其DNA, 采用细菌16S rDNA通用引物序列进行PCR扩增, 胶回收、测序后, 进行Blast比对分析。试验结果表明: YMA培养基上的菌落数量和种类均明显多于Ashby培养基上的菌落。田间一年生文冠果与田间二年生文冠果的根系内生菌情况存在差异。一年生文冠果的根系内生菌数量与种类略多于二年生文冠果。一年生文冠果根系中分离得到的主要内生菌为成团泛菌(Pantoea agglomerans)、根癌土壤杆菌(Agrobacterium tumefaciens)和产酸克雷伯菌(Klebsiella oxytoca)等; 田间二年生文冠果根系中分离得到的主要内生菌为假单胞菌属(Pseudomonas)细菌。固氮活性测定结果表明, 在所分离的7个菌株中, 6个测到了固氮酶活性, 其中鉴定为产酸克雷伯菌的菌株固氮酶活性显著高于其他菌株, 达到9.688 nmol·mg-1·h-1, 为文冠果固氮菌肥的菌种的筛选奠定了基础。 |
| 关 键 词： | 内生菌 鉴定 分离 文冠果 |
| 收稿时间： | 2009-09-02 |
Isolation, preliminary identification and nitrogen-fixation activity of endophytes from roots of one- and two-year-old Xanthoceras sorbifolia plants |
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| ZHANG Ye,LIAO Yi,CHEN Shang-Wu,MA Hui-Qin. Isolation, preliminary identification and nitrogen-fixation activity of endophytes from roots of one- and two-year-old Xanthoceras sorbifolia plants[J]. Acta Phytoecologica Sinica, 2010, 34(7): 839-844. DOI: 10.3773/j.issn.1005-264x.2010.07.009 | |
| Authors: | ZHANG Ye LIAO Yi CHEN Shang-Wu MA Hui-Qin |
| Affiliation: | College of Agriculture and Biotechnology, China Agricultural University, Beijing 100193, China College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China |
| Abstract: | Aims Endophytes are found in the root systems of various plants and play beneficial roles in root growth and function maintenance, especially when plants are under biotic or abiotic stress. Xanthoceras sorbifolia is a unique woody plant that grows in the northern part of China and is resistant to cold and drought and highly tolerant to poor soil. Moreover, it is considered a promising candidate for bio-diesel and bio-lubricant production. Our objective was to investigate endophytes in the roots of X. sorbifolia. Results will help in the selection and development of bacterial fertilizer to improve the growth and yield of X. sorbifolia, which grows in marginal lands.Methods We examined root systems of field-grown one- and two-year-old plants. After surface sterilization, endophytes were isolated with yeast-malt extract agar (YMA) and Ashby media respectively. Seven representative single colonies were selected according to their macro-morphology. After DNA extraction and purification, 16S rDNA PCRs were carried out with the universal bacterial primers. The PCR products were separated with electrophoresis, collected and purified. The 16S rDNA sequence similarity search of different bacteria was performed by Blast on NCBI against GenBank, and a similarity of 97% was set as the criterion for identity. Nitrogenase activity of the selected strains was assayed with ethylene production by GC.Important findings The number and type of colonies on YMA medium were significantly more than those on Ashby medium, as YMA medium contains a small amount of nitrogen and is more suitable for bacteria growth. The number and species of endophytes in one-year-old X. sorbifolia roots were slightly more than those in two-year-old plants. This may be because the roots of one-year-old plants were as a whole younger than those of two-year-old plants and were more suitable for the infection and survival of endophytic bacteria. The main bacteria species isolated from the roots of one-year-old plants were Pantoea agglomerans, Agrobacterium tumefaciens and Klebsiella oxytoca, while those from two-year-old plants were of the Pseudomonas genus. Six of seven strains demonstrated nitrogenase activity, including the activity of 9.688 nmol·mg–1·h–1 in K. oxytoca, which is significantly higher than other strains. This report on endophytes of X. sorbifolia roots provides the basis for bacteria fertilizer strain selection. |
| Keywords: | endophytes identification isolation Xanthoceras sorbifolia |
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