Abstract: Phosphate-solubilizing microorganisms were isolated from Italian ryegrass rhizospheres using PKO inorganic and Mengjinna organic culture media.The phosphate solubilizing capacities were investigated from 41 strains based on phosphate-solubilizing circle and the molybdenum blue method.Among them,13 strains had an ability to solubilize inorganic phosphate and D/d(diameter of phosphate-dissolving zone/diameter of bacterial clone) value was from 1.13 to 4;and 28 strains had an ability to solubilize organic phosphate on Mengjinna organic culture medium and D/d value was from 1.13 to 16.4.In liquid culture,the available phosphate increment was detected using molybdenum blue method from 15.6 mg·L^-1 to 557.2 mg·L^-1 by inorganic phosphate-solubilizing microorganism and from 52 mg·L^-1 to 341.6 mg·L^-1 by organic phosphate-solubilizing bacteria.Strains b9,b13 and f5 had a significantly higher ability of inorganic phosphate-solubilizing than others did.Strains B1 and B3 had a higher ability of organic phosphate-dissolving showing great potential for agricultural use in microbiological fertilizer and deserve further study.There was a significant correlation between the phosphate solubilizing capacity of inorganic phosphate dissolving microorganism and the pH of medium,whereas there was no such correlation for organic phosphate dissolving bacteria.

Key words: Italian ryegrass, Rhizosphere, Phosphate-solubilizing microorganism, Phosphate dissolving ability

摘要： 选用PKO(无机培养基)和蒙金娜有机培养基,从多花黑麦草(Lolium multiflorum L.)根际分离出41株具有溶磷能力的菌株,利用溶磷圈法和钼蓝比色法对其溶磷能力进行测定,其中13株具有溶解无机磷能力,其D/d值(溶磷圈直径与菌落直径比值)在1.13～4之间,用钼蓝比色法测定有效磷增量为15.6～557.2mg·L^-1。28株在蒙金娜有机磷培养基上形成明显透明圈,其D/d值在1.13～16.4之间,有效磷增量分别为52～341.6mg·L^-1。经解磷能力分析,b9,b13,f5菌株具有较强的解无机磷能力,D/d值为2.75,4,2.5,对无机磷的溶磷量为545,557.2,567.4mg·L^-1;溶解有机磷能力较强的菌株有2株(B1和B3),D/d值分别为11和16.4,对有机磷的溶磷量均为341.6mg·L^-1,这些菌株在后续微生物菌肥研制中具有较大潜力;pH与解无机磷菌株的溶磷量有显著的负相关性,而与解有机磷菌株的溶磷量没有显著相关性,这可能与微生物解有机、无机磷的机理不同有关。

关键词: 多花黑麦草, 根际, 解磷菌, 解磷能力