Effects Of Phosphorus On Growth And Development Characteristics, Grain Yield And Quality Formation Of Wheat

The phosphorus efficiency experiment with 12 medium-gluten wheat varieties and 12 weak-gluten wheat varieties was carried out on the field of Crop Cultivation and Physiology Key Laboratory of Jiangsu Province, Yangzhou University in 2005-2007. Grain yield per plant, phosphorus fertilizer use efficiency and agronomic efficiency under non-phosphorus fertilizer and phosphorus fertilizer treatments were used as main cluster analysis indexes, to select the high phosphorus efficiency varieties and low phosphorus efficiency varieties, and to investigate the effects of phosphorus on growth and development of wheat with different end use and the physiological mechanism of phosphorus efficiency differences.To investigate the effects of phosphorus on grain yield and quality of weak-gluten wheat, weak-gluten wheat varieties Yangmai 13, Yangmai 15, Ningmai 9 and Ningmai 13 were used as test materials. The experiment was carried out on the field of Taixing Regional Agriculture Research Institute of Jiangsu, and on the experimental field of Crop Cultivation and Physiology Key Laboratory of Jiangsu Province, Yangzhou University in 2005-2007. To improve grain yield and fertilizer use efficiency, effects of different kinds of phosphorus fertilizer(compound fertilizer, diammonia phosphorus, calcium superphosphate) and different P applications on grain yield and quality in weak-gluten wheat were studied in P deficient soil (available P 6.37mg·kg-1).The main results were as follow.1. The difference in the nespoonse to phosphorus absorption and utilization efficiency among wheat varieties did exist, accordingly, wheat varieties could be dividied into 3 groups, high phosphorus efficiency varieties, low phosphorus efficiency varieties and normal varieties. Phosphorus accumulation amount plants at maturity stage was not suitable for measuring phosphorus efficiency, Phosphorus accumulation amount high phosphorus efficiency varieties at maturity stage was not the greatest, and phosphorus accumulation amount low phosphorus efficiency varieties at maturity stage was not the lowest, but high phosphorus accumulation and high phosphorus translocation rate in grains were associated with high grain yield. So phosphorus accumulation and phosphorus translocation rate in grains could be used to measure phosphorus efficiency. Grain yield, phosphorus fertilizer use efficiency and agronomic efficiency varieties with high both under phosphorus fertilizer application treatment and non-phosphorus fertilizer treatment could considered as high phosphorus efficiency varieties ,including Yangmai 9, Yangmai 13, Ningmai 13, Zhengmai 004, Ningmai 8 in the experiment.The differences between phosphorus fertilizer application treatment and non-phosphorus fertilizer treatment in leaf area per plant, dry matter per plant and SPAD values in flag leaves were not significant under low phosphorus stress, and the differences of main stem and tillers number per plant, earing percentage of main stems and tillers, grain yield per pot were significant. Photosynthetic rate of flag leaves, soluble protein content in flag leaf, root volume, total absorbing area, active absorbing area and root activity decreased faster under non-phosphorus fertilizer treatment than under phosphorus fertilizer application treatment. It showed that flag leaf released more inorganic phosphorus to meet the demand of wheat under the non-phosphorus fertilizer treatment, and phosphorus could delay senescence to supply enough grain-filling matter.2. Different kinds of phosphorus fertilizer could increase grain yield and improve grain quality of weak-gluten wheat. Tiller number per plant, earing percentage of main stems and tillers, spike number per unit area, dry matter production and dry matter accumulation amount after anthesis all increased when phosphorus fertilizers were applied. Under the same nitrogen (N) application amount and K2O application amount, the order of the effects of different kinds of phosphorus were compound fertilizer>diammonia phosphorus>calcium superphosphate, and the differences were significant.Grain protein content under different kinds of phosphorus fertilizer treatments all significantly decreased, but protein yield per unit area increased, grain protein content under all kinds of phosphorus fertilizer treatments were lower than 11.5%, and the effects of different kinds of phosphorus fertilizer on starch content and its components were significant, total starch content, amylose content and amylopectin content in grains were all significantly reduced by different kinds of phosphorus fertilizer, and the effects were different with different wheat varieties. Wet gluten content in grains under all kinds of phosphate fertilizer treatments were lower than 22%, and dough stability time was not longer than 2.5 min under the compound fertilizer and diammonia phosphorus treatments, which could meet the state standard of People's Republic of China on high quality weak gluten wheat (GB/T17893-1999).Of the three kinds of phosphorus fertilizer, LAI, SPAD values of flag leaves, photosynthetic rate of flag leaves and SOD activity in flag leaves were the greatest, but MDA content in flag leaves was the lowest under the compound fertilizer treatment. It indicated that compound fertilizer was the best for increasing grain yield and improving grain quality.3. Basal:top dressing application ratio 0.5:0.5 phosphorus fertilizer with the same P application amount was better than 1.0:0 for increasing grain yield and improving grain quality. Dry matter production, main stem and tiller numbers, earing percentage of main stems and tillers, grain yield increased with the rising of P application amount below 108 kg P2O5 ha.Grain protein, amylose, amylopectin, total starch and wet gluten contents were the lowest when P application was 108 kg/ha under the two phosphorus fertilizer treatments. Grain protein yield was the highest when P application was 108 kg/ha, and it reduced with P application rising.According to the results above, compound fertilizer(N 16%,P2O5 16%,K2O 16%) with 108 kg/ha P2O5 application amount and 0.5:0.5 basal:top dressing application were the best to raise the grain yield and improve grain quality of weak gluten wheat in the experiment.