枣根际解磷细菌的筛选及其解磷机理研究

发布时间：2018-06-13 02:16

本文选题：解磷细菌 + 筛选　；参考：《新疆农业大学》2016年博士论文

【摘要】：枣源于我国,是我国独具特色的果树树种,具有抗旱、耐贫瘠、抗风、抗盐碱、种植后丰产稳产、适宜大面积发展等特点,已成为近年来新疆快速发展起来的一项增加农民收入的主导产业。然而随着化肥使用量的增加,其负面影响日益凸显。探寻新的肥源,尤其是生物肥替代或部分替代化肥的研究倍受关注。本研究以新疆枣主产区枣根际土壤为材料,进行了解磷细菌的分离、筛选和16S rDNA鉴定,并研究其解磷机理。取得了以下结果:(1)就微生物总量来说,4年生骏枣根际土壤的微生物数量高于8年生骏枣;从根际促生菌上看,8年生骏枣根际促生菌的总量要高于4年生根际促生菌,在不同种类的促生菌上表现出一定的差异。枣根际土壤促生菌的种类和数量与根际土壤养分有关,根际土壤速效磷的含量影响固氮菌和解无机磷细菌的分布,解钾细菌的数量与土壤碱解氮的含量密切相关,相关系数为0.88。(2)采用溶磷圈初筛和摇瓶复筛法筛选出土样中的解磷细菌,并对解磷细菌的16S rDNA进行测序,通过Blast检索同源序列,鉴定解磷细菌的种属,主要为Bacillus sp.、Acinetobacter sp.、Pseudomonas sp.、Enterobacter sp.等4个属的细菌。(3)在磷酸三钙无机磷培养基中,所筛选出的20个菌株在摇瓶培养下均有溶磷效果,其中P7、P13的能力最强,解磷量达到300μg/m L以上,菌株解磷量与培养液pH值的呈极显著负相关。(4)在蒙金娜有机磷培养基中,有3菌株对卵磷脂有较强的解磷能力,P3、P7、P9与对照间差异显著,菌株解磷量与培养液的pH值呈极显著负相关。(5)筛出来的20个菌株对磷酸钙和磷酸铝均有不同程度的降解能力,对磷酸钙降解能力很强的菌株P7、P13解磷酸铝效果也相对较好。20个菌株对磷酸铁和植酸钙降解能力较差。(6)有机酸的种类和数量对无机磷的溶解具有重要的作用,其中其中乙酸、丙酮酸和丁酸效果最好。不同的菌株对pH环境适应性有差异,P7适应碱性环境,而P13则喜好偏酸性环境。在解无机磷时,发酵液中的酸性磷酸酶占主导优势,而在降解有机磷时碱性磷酸酶起主导作用。(7)使用菌剂能够提高土壤碱解氮含量,增加土壤中有效磷的含量,提高土壤的有机质含量,降低土壤pH值,但是,单一菌剂大多只在一个或两个方面起作用,并且菌剂的效果受环境的影响较大。解磷菌剂能够改善果实的品质,尤其是糖、酸和Vc含量等。
[Abstract]:Jujube originated from China. It is a unique fruit tree species in China. It has the characteristics of drought resistance, barren resistance, wind resistance, salt and alkali resistance, high yield and stable yield after planting and suitable for large area development. It has become a leading industry for increasing farmers' income in Xinjiang in recent years. However, with the increase of fertilizer use, its negative influence has become increasingly prominent. New fertilizer sources, especially biological fertilizer replacement or partial substitution of chemical fertilizer, have attracted much attention. In this study, the rhizosphere soil of jujube jujube in Xinjiang jujube was used as the material to study the isolation, screening and 16S rDNA identification of phosphorus bacteria, and to study the mechanism of phosphorus removal. The following results were obtained: (1) the microorganism total amount, 4 years old jujube Rhizosphere Soil Micro The number of organisms was higher than that of the 8 year old steed jujube; from the rhizosphere stimulating bacteria, the total amount of the rhizosphere bacteria of the 8 year old steed jujube was higher than that of the 4 year rooting probiotic bacteria. The species and quantity of the rhizosphere soil promoting bacteria in the rhizosphere of jujube were related to the nutrient of the rhizosphere soil, and the content of available phosphorus in rhizosphere soil affected the nitrogen fixing bacteria and the nitrogen fixing bacteria and the content of the rhizosphere soil. The distribution of inorganic phosphorus bacteria, the number of potassium solubilizing bacteria is closely related to the content of soil alkali hydrolysable nitrogen, the correlation coefficient is 0.88. (2), the phosphorus solubilizing bacteria in the soil samples are screened by the initial screening of phosphate solubilizing ring and the shake flask rescreening method, and the 16S rDNA of the phosphate solubilizing bacteria is sequenced and the species of phosphate solubilizing bacteria are identified by Blast detection, mainly Bacil. LUS sp., Acinetobacter sp., Pseudomonas sp., Enterobacter sp. and other 4 genera bacteria. (3) in the inorganic phosphorus phosphate medium of tricalcium phosphate, the 20 strains screened in the shake flask culture have the effect of phosphorus dissolution, in which the ability of P7, P13 is the strongest, the amount of phosphorus is up to 300 mu g/m L, and the amount of phosphorus in the strain is significantly negatively correlated with the value of the culture solution. 4) in the monmona organophosphorus medium, 3 strains had strong phosphate solubilizing ability to lecithin, and there was significant difference between P3, P7, P9 and the control. (5) the 20 strains of the screened strains had the ability to degrade the calcium phosphate and aluminum phosphate in different range, and the strain of calcium phosphate, which has a strong ability to degrade calcium phosphate, P7, The effect of P13 aluminum phosphate solution is also relatively better than that of.20 strain on the degradation of ferric phosphate and calcium phytate. (6) the species and quantity of organic acids play an important role in the dissolution of inorganic phosphorus. Among them, acetic acid, pyruvic acid and butyric acid are the best. The adaptation of different strains to pH environment is different, P7 is adapted to the alkaline environment and P13 is preferred. Acid phosphatase in the solution of inorganic phosphorus predominate, while alkaline phosphatase plays the leading role in the degradation of organophosphorus. (7) the use of bactericide can increase the content of soil alkaline nitrogen, increase the content of available phosphorus in soil, increase the content of soil organic matter and reduce the pH value of soil, but the single bactericide is mostly in one. One or two aspects play a role, and the effect of inoculants is greatly affected by the environment. Phosphate solubilizing bacteria can improve fruit quality, especially sugar, acid and Vc content.
【学位授予单位】：新疆农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S154.3;S665.1

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