The mechanism of rhizosphere phosphorus activation of two rape genotypes（Brassica napus L.） with different P efficiencies

Screening and developing low phosphor tolerance plants is an alternative way to relieve the P resource deficiency and improve the fertilizer use efficiency. Based on the pre-screening materials, the rhizosphere soil phosphorus activation mechanism of different P efficiency rape genotypes was studied. The results showed that whether the soil is fertilized with P or not, the P uptake and biomass of the high P efficient rape B56 (HP) are higher than those of the low P efficient rape B10 (LP). There are significant depletions of NaHCO3-Pi, NaHCO3-Po, NaOH-Pi and NaOH-Po in the rhizosphere of the two genotypes, and the depletion of HG is greater than that of LG. Significant enrichments of resin-Pi are observed in the rhizosphere, and HCl-Pi and residual-P are not depleted in the rhizosphere of both genotypes. In comparison, HG secretes more acid phosphatase, and the enzyme activity and NaHCO3-Po content are significantly negatively correlated. These results indicate that it is important to mineralize of soil organic P by the acid phosphatase.