Characteristics Of Phosphorus Efficiency And Fractions Of Phosphorus In Rhizosphere Soil Of High-p Efficiency Transgenic Rice

In order to identify the characteristics of P efficiency and its influence on P content in soil by growing high-P efficiency transgenic rice,japonica rice cultivar Nipponbare and its high-P efficiency transgenic rice:OsPT4 and PHO2 were used to study the differences in efficiency of absorption,utilization and translocation of P,and the differences in the characteristics of phosphorus fractions and the activity of alkaline phosphatase in rhizosphere soil.The main results were as follows:?1?The tillers,root length,root dry-weight,panicle dry-weight and biomass of OsPT4 and PHO2 were higher than those of Nipponbare.?2?Compared with the control,the phosphorus uptake efficiency increased by 3.18 times and 3.98 times in OsPT4 and PHO2 root,which increased by 0.92 times and 8.07 times,by36.59%and 29.44%in their leaves and panicles,respectively.The P utilization efficiency of OsPT4 and PHO2 stem was 2.77 times and 3.71 times higher than that of Nipponbare,and the translocation of phosphorus efficiency was 88.57%and 22.06%higher than that of control.?3?The concentration of total phosphorus in OsPT4 rhizosphere soil was significantly lower at heading stage than that of Nipponbare,but no significant difference was observed at the other growth stage of Os PT4 and in PHO2 rhizosphere soil during all the growth period.?4?The tendency of phosphorus fractions of OsPT4 and PHO2 showed no significant difference with Nipponbare during its growth period.The concentration of inorganic P fractions showed the same tendency in rhizosphere soil of OsPT4 and PHO2 during its growth period:Ca₁₀-P>O-P>Ca₈-P>Fe-P>Al-P>Ca₂-P;The moderate labile organic phosphorus was dominant in the organic phosphorus fraction,followed by the resistant organic phosphorus and moderate resistant organic phosphorus,while labile organic phosphorus was the lowest.?5?The activity of alkaline phosphatase in OsPT4 and PHO2 rhizosphere soil had no significant difference with Nipponbare's during its growth period.Higher P uptake efficiency,lower P utilization efficiency of leaf and higher translocation efficiency of P made OsPT4 and PHO2 more efficient of phosphorus.High-P efficiency transgenic rice material OsPT4 and PHO2 had no effect on phosphorus fractions and alkaline phosphatase activity in rhizosphere soil.