一株灰潮土解磷菌的解磷特性及其对花生的促生作用

为研究解磷菌能使土壤中被铁、铝等吸附固定的难溶性的非有效态磷转化为易于被植物吸收利用的有效态磷，促进农作物的生长。从南京长江南岸的潮土中分离筛选获得了一株解磷效果好、性状稳定的解磷细菌Y1。观测了菌株Y1形态及生理生化性状，测定其16S rDNA的保守序列。通过菌株生长和发酵条件试验，研究了该菌株在不同培养条件下的解磷能力。通过设置盆栽实验，研究了Y1菌株对花生生长的作用。实验结果初步确定菌株Y1为荧光假单胞菌(Pseudomonas fluorescens)，该菌株在碳源为葡萄糖、氮源为硝酸铵、初始pH 6~8、装液量为50/250 mL时，解磷效果最好。盆栽试验结果表明，接种菌株Y1的花生根长、根表面积、根直径分别比对照增加159.0%、133.0%、18.9%，植株对N、P、K的吸收量分别比对照高73.6%、26.6%、41.0%，差异均达显著水平。本实验从灰潮土中筛选出一株高效解磷菌Y1，不仅能够促进花生的生长、产量，而且能够增加花生植株对N、P、K的吸收。该研究结果为菌株Y1在农业生产中的应用提供了理论依据和实验基础。

Phosphate-solubilizing Capability of Bacterial Strain Y1 from Fluvo-aquic Soil and Its Promoting Effects on Peanut

Phosphate-solubilizing bacteria can convert sparingly insoluble phosphate fixed by iron or aluminum into available phosphorus which can be easily utilized by crops. In order to study it, we isolated a phosphate-solubilizing bacterial strain Y1 with stable character from the fluvo-aquic soil in Nanjing, China. We measured its morphological feature, physiological and biochemical characteristics, and determined its 16S rDNA conserved sequence. By designing an experiment of growth and fermentation of the strain, we explored the phosphate-solubilizing capability of Y1 under different culture conditions. In this experiment, we organized a pot experiment to study the growth-promoting of Y1 strain on peanut. The Y1 was identified as Pseudomonas fluorescens. It displayed a better phosphate-solubilizing capability when the carbon source was glucose, the nitrogen source was NH₄NO₃, the medium initial pH was 6-8, and the volume was 50/250 mL in liquid volume in flask. The results showed that treatment of peanut with strains Y1 significantly enhanced the total length, root surface area, root diameter by 159.0%, 133.0%, 18.9% compared with the control, and significantly enhanced the absorption of N, P, K by 73.6%, 26.6%, 41.0% compared with the control. We isolated a phosphate-solubilizing bacterial strain, which can promote the growth and yield of peanut and enhance the N, P, K absorption of plant. The results showed that there was potentiality for application of strain Y1 in agricultural production.