The Characteristics Of Yield Formation Of Rice With High P Uptake Efficiency And Grain Yield

Under the condition of nomal nutrient solution,114rice Chromosome Single Segments Substitution Lines were solution-cultured in2011and2012.Grain yield and yield components, dry weight and phosphorus concentration of individual organs, sink and source relationship, dry matter production and distribution, phosphorus absorption and distribution, morphological and physiological traits of root were measured at heading and/or maturity. Based on total phosphorus uptake at maturity and grain yield, the rice lines were clustered into7groups by the dynamic clustering method MinSSw (Minimum Sum of Squares within groups). Thro ugh analyzing the above traits among rice groups with different phosphorus efficiency and yield, we are able to clarify the main factors influencing the rice phosphorus uptake and use efficiency, to understand the basic characteristics of high-yield rice with better efficiency in phosphorus absorption. The study will provide useful information for improving rice phosphorus nutrition through genetic approaches or high-yield cultivation strategies. The main results were as follows:1. There were significant differences in phosphorus uptake or grain yield among different rice types. The type with biggest phosphorus absorption quantity was3.68times of the minimum one. The type with highest grain yield was2.69times of the minimum one. At maturity, enhancing phosphorus uptake was beneficial to improve the grain yield of cultivars.2.In terms of yield components. Spikelet per panicle and setting percentage of rice types with high P uptake efficiency and grain yield were high, panicle number per area and thousand seed weight were high too. Yield components have different degrees of influence on phosphorus uptake and grain yield, the influence of panicle number per area and spiikelet number per panicle on phosphorus uptake were significantly bigger than setting percentage and thousand seed weight.3. In terms of source and sink relationship. Rice types with high P uptake efficiency and grain yield showed significantly higher LAI (effective、high effective and total leaf area)、sink potential and net assimilation rate than those with low P uptake efficiency and grain yield. There were close relationships between LAI at heading stage, sink potential, net assimilation rate and phosphorus uptake, grain yield.4. In terms of dry matter production and distribution. Rice types with high P uptake efficiency and grain yield showed high dry matter production (heading stage、maturity and grain filling stage).5. In terms of phosphorus uptake and distribution.(1) In terms of phosphorus uptake. Plant phosphorus-containing rate of rice types with high P uptake efficiency and grain yield at heading stage were at the medium level, but the plant phosphorus-containing rate at mature was relatively high. P uptake at heading stage, grain filling stage, phosphorus absorption ratio at grain filling stage and P uptake of single panic le(heading stage, mature and grain filling stage), the intensity of phosphorus absorption (the group and single panicle) of rice types with high P uptake efficiency and grain yield were high. The effect of the Phosphorus absorption at grain filling stage, dry production at mature, phosphorus absorption of single panicle, the intensity of phosphorus absorption to Phosphorus absorption quantity is larger than the Phosphorus absorption at heading stage, the whole plant phosphorus-containing rate, panicle number per area and growth days.(2)In terms of the distribution and utilization efficiency of phosphorus. Rice types with high P uptake efficiency and grain yield had low phosphorus absorption ratio of root and spike at the heading stage and the mature, but high of stem and leaf, the phosphorus use efficiency for grain output, the phosphorus dry matter production efficiency and the phosphorus harvest index of rice types with high P uptake efficiency and grain yield were relatively low.6. In terms of the traits of the root. There were significant differences in the dryweightofroot, a-NA oxidation capacity at the heading stage and the dryweight, the longest root length, plural root length per plant, thickness of adventitious root at the mature, the crown root ratio at the heading stage and the mature between different types of rice. These traits of rice types with high P uptake efficiency and grain yield showed higher relatively. The dryweightofroot, the longest root length, plural root length per plant, thickness of adventitious root at the heading stage, the weight of root at the mature, the crown root ratio at the heading stage and the mature are closely related to the phosphorus uptake and the yield.