Characteristics of Phosphorus Uptake and Phosphorus Fractions in the Rhizosphere Among Different Phosphorus Efficiency Wheat Cultivars

【Objective】In order to provide a basis for exploring the mechanism of high phosphorus use efficiency and uptake efficiency for wheat cultivars,the characteristics of phosphorus fractions in rhizosphere soil of different phosphorus efficiency wheat cultivars and activation characteristics of different forms of phosphorus were investigated.【Method】By the method of soil culture experiment,high phosphorus efficiency(CD1158-7,Sheng A3 yi 03-4) and low phosphorus efficiency cultivars(Yu 02321) were used to evaluate their differences in dry matter weight,phosphorus accumulation,water soluble phosphorus,inorganic P fractions,organic P fractions in rhizosphere and non-rhizosphere soils under different P application rates(0,10,20,30 mg.kg-1soil).【Result】 With the increasing P fertilizer amounts,the dry matter weigh and phosphorus accumulation of different phosphorus efficiency wheat increased.And dry matter weigh and phosphorus accumulation of high phosphorus efficiency cultivars were significantly higher than that of low phosphorus efficiency cultivar.The concentration of water soluble phosphorus in rhizosphere was lower than that of non-rhizosphere soils in different P treatments.At low P application rates(0,10,20 mg.kg-1soil),there were deficit with water soluble phosphorus of high phosphorus efficiency cultivars in rhizosphere.But the results showed that water soluble phosphorus of high phosphorus efficiency cultivars enriched in rhizosphere under high P application rates(30 mg.kg-1soil).In the whole,concentration of inorganic P fractions showed the same tendency in rhizosphere and non-rhizosphere soils: Ca10-PO-P,Fe-PAl-PCa8-PCa2-P,and the Ca10-P concentration of inorganic phosphorus was over 50% of the total.The Ca2-P concentration of high phosphorus efficiency cultivars was 1.22 times and 1.23 times,1.31 times and 1.59 times higher than that of low phosphorus efficiency cultivar in rhizosphere without or 10 mg.kg-1soil P application rate.The Al-P concentration of low phosphorus efficiency cultivar was 1.13 times and 1.23 times higher than those of high phosphorus efficiency cultivars in rhizosphere without P application,respectively.O-P and Fe-P in rhizosphere reduced for different phosphorus efficiency wheat cultivars with the decreasing P application.The moderate labile organic phosphorus was dominant in the organic phosphorus fraction,followed by the moderate resistant organic phosphorus and resistant organic phosphorus,while labile organic phosphorus was the lowest.The labile organic phosphorus concentration of low phosphorus efficiency cultivar(Yu 02321) was 2.00 times and 1.76 times,1.68 times and 1.63 times than those of high phosphorus efficiency cultivars(CD1158-7,sheng A3 yi 03-4) in rhizosphere without and 10 mg.kg-1 P application,respectively.【Conclusion】Wheat cultivars of high phosphorus use efficiency and uptake efficiency had the capacity of stronger phosphorus accumulation,material production and water-soluble phosphorus absorption.For wheat cultivars of high phosphorus use efficiency and uptake efficiency,the activation capacities of Al-P,Ca-P and organic phosphorus were higher than those of wheat cultivars of low phosphorus use efficiency and uptake efficiency.