Stable Quality Traits of Soft Winter Wheat under Nonlimiting Nitrogen Conditions

Abstract

Bread wheat (Triticum aestivum L.) quality is determined by genotype and environment. The aim of this work was to find gluten proteins related to wheat quality independent of crop environment and under nonlimiting N conditions for wheat yield. Field experiments assessing the effect of N rate in soft winter wheat quality parameters were performed in three locations in Navarra (in northern Spain) during 5 yr with a randomized complete block design and four replications. The minimum N rate that produced maximum grain yield (Nop) was determined for each year. Grain samples from N treatments equal to or above Nop were milled. Gliadins and glutenins were extracted from white flour. They were separated into α plus β‐, γ‐, ω‐gliadins, high molecular weight glutenin subunits (HMW‐GS), and low molecular weight glutenin subunits (LMW‐GS) and they were quantified by reverse phase high performance liquid chromatography (RP‐HPLC). Although an increase in N fertilizer rate led to increases in gliadin and glutenin contents as well as dough strength and extensibility, environmental variability differentially affected the synthesis or polymerization of each gliadin and glutenin type. In terms of protein fractions, both HMW‐GS and LMW‐GS were determined to be the protein fractions best correlated to dough strength (R2 = 0.78) whereas γ‐gliadins were the best correlated to dough extensibility (R2 = 0.72) independent of N nutrition, environmental conditions, and water availability.

Ammonium as sole N source improves grain quality in wheat

“…In terms of protein fractions, both HMW-GS and LMW-GS were determined to be the protein fractions best correlated to dough strength independent of N nutrition, environmental conditions and water availability. 30 The proportion of the two types of glutenins in flour -HMW-GS and LMW-GS -is thought to be an important indicator of flour quality because it can affect the nature of large glutenin polymers that confer elasticity and strength to dough made from wheat flour. 39 The increase in total glutenin content was accompanied by an increase of both LMW-GS and HMW-GS, the slope regression between LMW-GS and total glutenin content being almost two times greater than that of HMW-GS (0.85 vs. 0.15, Fig.…”

“…In addition, the amount of glutenin macropolymers in grain is more sensitive to growth conditions than the grain protein content . González‐Torralba et al . observed that, in rainfed conditions, flour N content could not explain completely the variations in breadmaking quality parameters, but glutenin content could be used to estimate dough strength.…”

“…observed that, in rainfed conditions, flour N content could not explain completely the variations in breadmaking quality parameters, but glutenin content could be used to estimate dough strength. In terms of protein fractions, both HMW‐GS and LMW‐GS were determined to be the protein fractions best correlated to dough strength independent of N nutrition, environmental conditions and water availability . The proportion of the two types of glutenins in flour – HMW‐GS and LMW‐GS – is thought to be an important indicator of flour quality because it can affect the nature of large glutenin polymers that confer elasticity and strength to dough made from wheat flour .…”

“…Two subsamples from each flour sample were extracted using a sequential extraction procedure based on Triboi et al ., with minor modifications . From each subsample, gliadins and glutenins were respectively separated by reversed‐phase high‐performance liquid chromatography (RP‐HPLC) in a Waters 2695 Separations Module (Waters Corp., Milford, MA, USA) using a Europa Protein 300 C18 column (300 Å, 5 µm, 250 × 4.6 mm) at 50 °C with Guard Column Protein 300 C18 (10 × 3.2 mm) (Teknokroma, Sant Cugat del Vallés, Spain).…”

“…59 In addition, the amount of glutenin macropolymers in grain is more sensitive to growth conditions than the grain protein content. 60 González-Torralba et al 30 observed that, in rainfed conditions, flour N content could not explain completely the variations in breadmaking quality parameters, but glutenin content could be used to estimate dough strength. In terms of protein fractions, both HMW-GS and LMW-GS were determined to be the protein fractions best correlated to dough strength independent of N nutrition, environmental conditions and water availability.…”