Nitrogen redistribution from the roots in post-anthesis plants of spring wheat

Abstract

The aim of this study was to investigate post-anthesis N redistribution from the roots to other organs in the wheat plant. Two cultivars of spring wheat (Triticum aestivum L.) Sport and WL were grown to maturity in culture solution with stepwise-decreasing N supply and 15 N before sampling. The N concentration of dry weight in the roots decreased from anthesis to full maturity. At maturity the root N concentration was 5.5 mg g −1 dry weight for Sport and 4.9 mg g −1 dry weight for WL, while the main shoot N concentration was 2.1 mg g −1 dry weight for Sport and 2.2 mg g −1 dry weight for WL. The roots were a major sink for N taken up post-anthesis and contained the main proportion of the 15 N during the whole post-anthesis period. The N redistributed from the roots contributed 24.3% of the total N amount in the grains at maturity in cv Sport and 8.7% in cv WL. For cv Sport, 46.3% of the root N amount was redistributed to other parts of the plant and for WL 25.4%. The tiller grains were supplied with N from the 15 N applied post-anthesis to a higher degree than the main shoot grains. The transport capability was maintained until 12 days after complete yellowness. We concluded that wheat has a great ability to redistribute nitrogen from the root system to the grains.

Genotypic Variationin Dry Weight and Nitrogen Concentration of Wheat Plant Parts; Relations to Grain Yield and Grain Protein Concentration

“…Variation in maturation time might have been present among the investigated genotypes, although maturation time was not recorded in the present investigation. A third variable influencing GNC is the amount of N reallocated from the biomass to the grain, which might vary among the genotypes (Andersson et al, 2005). Reallocation of N from the leaves and stem to the grain was used as a certain breeding criteria when the genotype Sport was bred (Oscarson, 1996).…”

“…and a smaller root volume might also contribute to fewer options for the plant to reach the important nutrients in the soil for a good development of the crop (Hoad et al, 2001). High RNC is not desirable as it might contribute to N losses from the roots to the soil after harvesting by the mineralization process (Andersson et al, 2005) and i.e. higher N leaching (Riley et al, 2001).…”

Fallow replacement and alternative nitrogen management for reducing nitrate leaching in a semiarid region

“…In both study years, TN deposition was estimated to be 1.6 kg N ha -1 year -1 using data from the EPA's nearest atmospheric deposition station in Glacier National Park (Elevation 976 m; U. S. Environmental Protection Agency 2014). The TN amount in the root biomass was set equal to 20% of the aboveground N, based on wheat root N:shoot N ratios (Andersson et al 2005). Broadcast urea volatilization amounts were estimated at 14% of applied N based on measured average ammonia volatilization losses from early spring (Mar 24-Apr 20) applications for eight central and north central Montana trials, including three within the JRW (Engel et al 2011;Engel and Jones 2014).…”

Macromolecular changes and nano-structural arrangements in gliadin and glutenin films upon chemical modification

“…Both the gliadin and glutenin were lyophilized and ground into powder (Yellow Line A10, IKA) and stored at −20 • C for further use. The protein content of gliadin and glutenin was measured by the Dumas method [22] (nitrogen volatilization by Flash 2000 NC Analyzer, Thermo Scientific, USA) and was found to be 91% for gliadin and for glutenin 75%.…”