新疆核桃根际促生菌的筛选及鉴定

发布时间：2018-08-17 18:18

【摘要】：以新疆核桃根际原位土著微生物为研究对象,通过采集核桃根际土壤进行分离纯化,筛选对核桃树具有促生作用且能在其根际稳定定殖的优质高效菌株,为今后核桃专用微生物肥的研制提供菌株材料。本研究以从阿克苏、和田、喀什三个新疆核桃主产区采集的根际土壤为材料,先利用选择性培养基对核桃根际促生菌(解磷菌、解钾菌、固氮菌和拮抗菌)进行分离,再分别采用溶磷圈初筛和液体摇瓶复筛法、火焰光度计法、总氮差值法以及对峙实验法对各促生菌的解磷、解钾、固氮以及拮抗能力进行测定,然后,将筛选出的菌株通过利福平诱导后进行大田定殖实验以确保各能力的稳定性,最后,采用16S rDNA进行分子鉴定。结果如下:1.通过测定其促生能力,共筛选出64株根际促生菌,其中14株解磷菌,16株解钾菌,20株固氮菌,14株拮抗菌。2.经耐利福平诱导后,筛选出13株解磷菌,14株解钾菌,10株固氮菌,7株拮抗菌。3.对筛选出的菌株进行大田定殖实验后,将回收的菌株进行菌落计数并再次测定其促生能力,最终筛选出11株解磷菌,10株解钾菌,8株固氮菌,7株拮抗菌。4.采用16S rDNA方法,初步鉴定出解磷菌属于4个属,分别为微杆菌属(Microbacterium)、不动杆菌属(Acinetobacter)、葡萄球菌属(Staphylococcus)和假单胞菌属(Pseudomonas);解钾菌属于3个属,分别为Microbacterium、芽孢杆菌属(Bacillus)和Pseudomonas;固氮菌属于5个属,分别为根瘤菌属(Rhizobium)、Pseudomonas、中华根瘤菌属(Sinorhizobium)、节杆菌属(Arthrobacter)和Bacillus;拮抗菌属于3个属,分别为链霉菌属(Streptomyces)、Bacillus和Pseudomonas。其中,Pseudomonas为解磷菌、解钾菌和拮抗菌的优势种属,而固氮菌的优势种属为Rhizobium。
[Abstract]:By collecting walnut rhizosphere soil to isolate and purify walnut rhizosphere native microorganisms in Xinjiang, the high quality and high efficiency strains which can promote the growth of walnut trees and stabilize colonization in the rhizosphere of walnut were screened. To provide strain material for the development of special microbial fertilizer for walnut in the future. In this study, the rhizosphere soil collected from three main producing areas of walnut, Aksu, Hotan and Kashi, was isolated from the rhizosphere promoting bacteria (phosphorus releasing bacteria, potassium lytic bacteria, nitrogen-fixing bacteria and antagonistic bacteria) by selective culture medium. Then the phosphorus release, potassium, nitrogen fixation and antagonistic ability of the bacteria were determined by the first screening method of dissolved phosphorus ring and the method of liquid flask recombination, flame photometer, total nitrogen difference method and confrontation experiment, respectively. The selected strains were induced by rifampicin for field colonization to ensure the stability of each ability. Finally, 16s rDNA was used for molecular identification. The result is as follows: 1. A total of 64 rhizospheric growth-promoting bacteria were screened by measuring their growth promoting capacity, of which 14 were phosphorolytic bacteria, 16 were potassium monophosphate bacteria, 20 were nitrogen-fixing bacteria, 14 were antagonistic bacteria. After induced by rifampicin, 13 strains of phosphorolytic bacteria, 14 strains of potassium bacteria, 10 strains of nitrogen-fixing bacteria, 7 strains of antagonistic bacteria, were selected. After the field colonization experiment was carried out, the recovered strains were counted and their ability to promote growth was determined again. Finally, 11 strains of phosphorus bacteria, 10 strains of potassium bacteria, 8 strains of nitrogen-fixing bacteria, 7 strains of antagonistic bacteria, were screened out. By using 16s rDNA method, four genera of phospholytic bacteria were identified, including microbacilli, (Microbacterium), Acinetobacter, Staphylococcus, (Staphylococcus), Pseudomonas, (Pseudomonas);, and potassium lyase, belonging to 3 genera. They are Microbacterium, Bacillus (Bacillus) and Pseudomonas, nitrogen-fixing bacteria belong to 5 genera, (Rhizobium), (Arthrobacter) and Bacillus, and antagonistic bacteria belong to three genera, (Streptomyces) Bacillus and Pseudomonas, respectively. Among them, Pseudomonas is a phospholytic bacteria, potassium bacteria and antagonistic bacteria are dominant species, while Rhizobium is the dominant species of nitrogen-fixing bacteria.
【学位授予单位】：新疆农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S664.1;S154.3

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