不同磷效率小麦对磷的吸收及根际土壤磷组分特征差异

【目的】研究不同磷效率小麦根际土壤磷组分特征及磷高效小麦对土壤中不同形态磷素的活化利用特征，以探明磷高效小麦高效吸收利用磷素机理。【方法】在土培盆栽条件下，以小麦磷高效品种CD1158-7、省A3宜03-4和低效品种渝02321为材料，研究每kg土中施磷0、10、20和30 mg（表示为0、10、20、30 mg?kg-1）条件下其生物量、磷素积累量、根际与非根际土壤水溶性磷、无机磷组分、有机磷组分的浓度差异。【结果】不同磷效率小麦生物量、磷素积累量随着施磷量增加均有不同程度的增加，且高效品种显著高于低效品种。不同施磷处理，根际土壤水溶性磷浓度均低于非根际土壤。在低磷处理（不施磷、施磷10、20 mg?kg-1）条件下，高效品种根际土壤水溶性磷出现了亏缺，而施磷量较高（施磷30 mg?kg-1）时，其根际土壤水溶性磷则出现了富集。根际与非根际土壤无机磷组分浓度为Ca10-P＞O-P、Fe-P＞Al-P＞Ca8-P＞Ca2-P，且Ca10-P浓度占无机磷总量的50%以上。不施磷、施磷10 mg?kg-1，高效品种根际土壤中Ca2-P浓度是低效品种的1.22和1.23倍、1.31和1.59倍。低效品种根际土壤Al-P浓度在不施磷处理下是高效品种1.13和1.23倍。施磷量减少，不同磷效率小麦根际土壤均表现出O-P、Fe-P的减少。根际与非根际土壤4种有机磷组分中，以中活性有机磷浓度最高，其次为中稳性有机磷和高稳性有机磷，而活性有机磷的浓度最低。不施磷和施磷10 mg?kg-1处理，低效品种渝02321根际土壤活性有机磷浓度是高效品种CD1158-7和省A3宜03-4的2.00与1.76倍、1.68与1.63倍。【结论】磷高效小麦具有较强的磷素积累、物质生产和水溶性磷吸收能力。低磷胁迫下，磷高效品种活化吸收Al-P、Ca-P、活性有机磷能力强于低效品种。

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-P>O-P,Fe-P>Al-P>Ca8-P>Ca2-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.