Abstract:
The growth rate and phosphate-dissolving ability of phosphate-dissolving rhizobium SL01 in different calcium phosphate Ca
3(PO
4)
22 content of substrate and storage temperatures were determined. Based on solid culture, the results indicate enhanced colony growth with increasing levels of Ca
3(PO
4)
2. Colony diameter of treatment with 8.0 g·L
?1 Ca
3(PO
4)
2 is respectively 16.9%, 27.7%, 30.1% and 32.7% higher than that of 5.0 g·L
?1, 3.0 g·L
?1, 1.0 g·L
?1 and 0.5 g·L
?1 Ca
3(PO
4)
2 treatments. At Ca
3(PO
4)
2 range of 0~8.0 g·L
?1, the phosphate-dissolving ability of the strain is not obviously different. It is therefore more suitable to use
D/d (phosphate-dissolving ring diameter to colony diameter) ratio in measuring phosphate-dissolving ability of strains in solid surrounding such as soil. Bacteria liquid is best preserved under 15 ℃, followed by 4 ℃. Phosphate-dissolving ability of SL01 under different storage temperatures is -18 ℃ > -10 ℃ > 4 ℃ > 15 ℃ > 28 ℃ > 35 ℃. The order of SL01 colony diameter under different storage temperatures is 4 ℃ > 15 ℃ > -18 ℃ > 28 ℃ > -10 ℃ > 35 ℃. Order of viable bacteria amount of strain preserved for 60 d under different temperatures is 15 ℃ > 4 ℃ > 28 ℃ > -10 ℃ > 35 ℃ > -18 ℃.