一株溶磷菌的分离鉴定及对西瓜根系的促生效应

Separation and identification of a phosphorus solubilizing bacteria and its promoting effect on watermelon root

溶磷菌具有提高土壤中磷元素的植物利用率,促进植物生长的作用。利用选择性培养基,在植物根际分离纯化溶磷菌并鉴定,进一步研究了它们对西瓜幼苗根系的影响。结果表明,在获得的7株具有溶磷能力的菌株中,菌株HYL01具有较强的溶磷能力,经鉴定属于Pantoea ananatis,溶解Ca3（PO4）3的有效量为140.26 mg·L^-1,溶磷量与p H值相关性为-0.743,菌剂施用后,处理组比对照组西瓜幼苗的总根长、根表面积、根体积和比根长的增加量分别为44.38%,7.58%,63.65%和16.32%,并且显著增加了根系直径为0-0.5 mm范围内的西瓜幼苗根长所占的比例。因此,新分离鉴定的Pantoea ananatis HYL01号菌株具有较高的溶解无机磷的能力,对西瓜幼苗根系生长具有促进作用,能有效提升细根所占比例,具有制备复合微生物菌肥的潜力。

Rhizosphere phosphate solubilizing bacteria can improve utilization of phosphorus in soil and promote plant growth. In this study, the bacteria, which could solubifize phosphate efficiently, were identified by selective medium and their effects on the root growth of watermelon seedling were investigated in a pot experiment. The results showed that 7 strains with the capability of phosphate-dissolving were identified, HYL01 strain was the strongest than other strains in the capacity of phosphate solubilization, and was classified as Pantoea ananatis. It could dissolve Ca3 （ PO4 ）3 with a rate of 140. 26 mg·L^-1, and the correlation coefficient was -0. 743 between the solubilizing capacity of phosphate and pH value. Compared with the control, the total root length, root surface area, root volume and specific root length of watermelon seedlings were increased by 44. 38% , 7.58%, 63.65% and 16. 32% by HYL01 strain. The proportion of fibrous roots, which had a diameter in the range of 0 - 0. 5 mm, was increased significantly in watermelon seedlings. Therefore, HYL01 strain had the capacity to dissolve inorganic phosphorus efficiently and could promote root growth of watermelon seedlings. It is an excellent candidate for compound microbial fertilizer.