【作者】 胡纯国；

【导师】 冯玉杰；

【作者基本信息】 哈尔滨工业大学 ， 环境科学与工程， 2007， 硕士

【摘要】 由于农田的不合理灌溉以及化肥的过度使用,使土壤受到破坏,植被的生长受到抑制,土地盐碱化加剧。随着人口膨胀耕地面积减少,盐碱地的治理和改良也越来越受到人们重视。这方面主要包括工程改良、化学改良及生物改良。工程改良短期效果明显,但工程投入大。化学改良见效比较快,但成本很高,而且副作用明显。因此,人们的观点逐步转向利用生物措施来治理盐碱地,并且认识到通过筛选利用耐盐品种,提高作物本身耐盐能力较之利用工程措施改良盐碱地要经济有效。同时,研究指出,要进一步巩固或提高盐碱地改良效果,防御土壤返盐,需要配合适当的农业措施,特别是培肥土壤。因此,本研究要筛选出耐盐碱解磷菌,用于促进盐碱地植物生长,从而达到生态修复盐碱地的目的。本论文从生态工程学和盐碱地生态修复的角度出发,选择松嫩平原典型的盐碱化草地作为研究对象,从盐碱土中分离筛选出两株耐盐碱解磷菌,通过生理生化指标测定及菌落形态、个体特征观察和MIDI系统鉴定,确定C111是乙酸钙不动杆菌,C141是近平滑假丝酵母。对解磷菌种环境适应性研究结果表明C111和C141两株菌种都具有比较高的耐渗透压及碱度的能力,在一定Ca2+浓度下能发挥解磷效果;在碳源利用方面,C141菌株比C111具有更广泛和稳定的适应性。解磷菌溶解难溶磷酸盐是个复杂的过程,实验结果表明,两株菌可能通过分泌质子和有机物,通过酸化、螯和合离子交换的综合作用溶解难容磷酸盐。通过测试接种前后土壤有效磷的变化,考察了菌种对盐碱土环境的适应能力。研究结果表明接种菌种能提高盐碱土的有效磷。说明这两株菌能对盐碱环境有很好的适应性,并能发挥出解磷效果。为考察两株解磷菌能否促进羊草生长,我们在实验室进行了盆栽实验。发现接种C111和C141菌株种后,植株高度比对照组有明显增加,而且这种促进作用具有一定持续性。分析了不同菌种接种后羊草根际土壤有效磷的变化,初步研究表明,接种解磷菌能提高土壤有效磷,进而影响植物的生长。耐盐碱解磷菌不仅能适应盐碱土环境,而且能提高盐碱土的有效磷含量,改善土质。更多还原

【Abstract】 Soil saline-alkalifying is becoming more and more severe because of the unsuitable irrigation, eatra-using of fertilizers and vegetation destroying. People have paid more attention to the soil improvement and remediation, including Engineering, chemical and biological measures because of the expansion of population and the reduction of farmland. The construction effect of short-term was good but the input is great. Chemical measures can take effect in the short time with the high cost and side effects.They realized that it is more economical and effective to screen and identify enduring alkali variety than to utilize engineering measures in order to improve saline and alkaline land. So, people like to harness saline and alkaline land with biological treatment. The result of research indicate that in order to consolidate and improve treatment effect and defence the returntion of salts, agricultural measures are necessary, especially the improvement of soil fertility. Therefore, this study want to screen saline-alkali tolerance phosphate solubilizing bacteria used to promote plant growth, in order to ecologically restorat salineSongNen alkaline-saline plain was selected as research objective at present paper based on the view of eco-engineering and ecological rehabilitation of alkaline-saline land. Two strains which posseses strong phosphate-solubilizing capability were selected from alkaline-saline land. Strains of C111 and C141 were identified as Acinetobacter-calcoaceticus (C111) and Candida-parapsilosis (C141) through their physiological characteristics, morphology of colonies and individual, and MIDI analysis.The applicability to environmental factors, were thoroughly studied by determination of the phosphate-solubilizing capability of C111 and C141. Results showed that two strains can tolerate relatively high osmotic pressure and alkalinity and they could keep high phosphate-solubilizing capability in the condition of high concentration Ca2+ .The C141 had better Adaptability than C111, in the respect of carbon utilization. Phosphate solubilizing bacteria could dissolve phosphate and the process was complex. The results indicated that the phosphate solubilizing bacteria might excrete protons and organic compounds and they could solubilize insoluble phosphate through both the way of acidilation, anion-exchange and chelation.Medium was collected at various times after inoculation and centrifuged and the supernatant was measured for phosphate, in order to understand the applicability to alkaline soil. The experimental results presented here show that the microorganisms were able to increase the availability of P of the alkaline soil. It suggests that PSMs could be effective in alkaline soils.Taking the typical plant of Leymus chinensis as target research objective, the effects of inoculating C111 and C141 into laboratorial potted plant were investigated. After inoculation, the heights of Leymus chinensis were higher than than the control buring the whole experiment. The available phosphorous of rhizomes was also determined and the results implied the changes of phosphorous might be owing to the inoculation of C111 and C141 and this might be one of the reasons resulting in the growth of Leymus chinensis. Saline-alkali tolerance PSBs can not only adapt to alkaline-saline soil environment, but also improve the available Phosphorous and change the soil quality.更多还原