Abstract:

【Objective】 The aim of the experiment was to isolate a strain solubilizing various forms of insoluble-phosphate such as tricalcium phosphate, rock phosphate and lecithin and having antagonism reaction against soil borne diseases. 【Method】 Liquid culture medium was used to measure P-solubilizing activities of tricalcium phosphate, rock phosphate and lecithin and an in-door plate antagonism experiment was conducted to study its antagonistic activities against soil borne disease. 【Result】 Six strains solubilizing tricalcium phosphate, rock phosphate and lecithin were isolated from five calcareous soils collected from Jiangsu and Anhui provinces by plate and broth assay. Strain P1 was the most effective for solubilizing tricalcium phosphate and lecithin after 7 days cultivation, with water-soluble phosphorus (WPS) concentration in the culture up to 674.5 μg?mL-1and 33.0 μg?mL-1, respectively, and strain P1 could also effectively solubilize rock phosphate with WSP concentration up to 132.3 μg?mL-1. After physiological characteristics identification and 16S ribosomal DNA gene sequence analysis, strain P1 was identified as Burkholderia gladioli. In addition, the results of plate antagonistic experiment showed that strain P1 had strong antagonistic activities against Phytophthoia capsici, Verticillium dahliae, Phytophthora parasitica var. nicotianae and Rhizoctonia solani. 【Conclusion】 Strain P1 could both effectively solubilize tricalcium phosphate, rock phosphate and lecithin and have antagonistic ability against several soil-borne pathogens.

Key words: phosphate solubilizing, Burkholderia gladioli, antagonism, P-solubilizing characteristics