滇池富磷区土壤中溶磷真菌的筛选及其对油菜的促生作用

    Screening of phosphate-solubilizing fungi from phosphate -rich soils in Dianchi and its effect on growth promoting in Brassica napus

    • 摘要: 从滇池富磷区的89份土样中筛选出48株溶磷真菌,采用钼蓝法测定这些真菌溶解Ca3(PO4)3的能力。结果表明培养液中可溶性磷含量在14.45~64.87?mg/L,其中菌株SPF46、SPF47和Mo-Po的溶磷能力最强,其培养液中可溶性磷含量分别达到55.44、59.78和64.87?mg/L。结合形态特征及ITS rDNA 系统亲缘关系分析,将PSF46鉴定为黄暗青霉(Penicillium citreonigrum),PSF47菌株鉴定为黑曲霉(Aspergillus niger),Mo-Po菌株鉴定为草酸青霉(Penicillium oxalicum)。在Ca3(PO4)3、FePO4.4H2O和AlPO4 3种磷源中,这3种溶磷真菌对Ca3(PO4)2的溶磷效果最好。通过盆栽试验表明这3种溶磷真菌对油菜具有较好的促生效果,单一菌株处理,根系增长率在10.16%~294.7%,株高增长率在32.19%~134.5%;叶片直径增长率在35.53%~170.5%;鲜质量和干质量增长率分别在30.71%~189.5%,56%~224%。3种溶磷真菌混合处理,根系增长129.4%,株高增加60.41%,叶片直径增加170.5%;鲜质量和干质量分别增加246.1%、272.2%。

       

      Abstract: Forty-eight isolates of phosphate solubilizing fungi (PSF) were isolated from 89 soil samples and their tricalcium phosphate (TCP) solubilization efficiencies were evaluated by Mo-blue method. The results showed that the concentration of soluble phosphates in liquid cultures ranged from 14.45 to 64.87 mg/L. SPF46, SPF47, and Mo-Po were the most efficient isolates releasing 55.44, 59.78 and 64.87 mg/L soluble phosphate in liquid cultures, respectively. By morphological features and ITS rDNA sequences homology analysis, the three isolates were identified as Penicillium citreonigrum, P. oxalicum and Aspergillus niger, respectively. They showed the highest phosphorus solubilization efficiency in the presence of TCP compared to the other tested FePO4.4H2O and AlPO4. Pot experiment showed that the inoculation of the three PSF isolates significantly increased the nape growth. Individual inoculation of the three isolates resulted in 10.16%-294.7% increase in root length, 32.19%-134.5% increase in plant height, 35.53%-170.5% increase in leaf diameter, 30.71%-189.5% in fresh weight and 56%-224% increase in dry weight, respectively. Meanwhile, a consortium of the three isolates showed 129.4% increase in root length, 60.41% increase in plant height, 170.5% increase in leaf diameter, 246.1% increase in fresh weight and 272.2% increase dry weight, respectively.

       

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