Survey of Grain Quality in United States Soft Wheat Germplasm.

Soft wheat (Triticum aestivum L.) quality depends upon genetic and environmental factors, which work both individually and in combination to produce specific grain, milling, and baking characteristics. Wheat breeders select for high grain yield and local adaptation, together with perceived targets (or limits) of grain quality using a number of quality parameters. This study surveyed all (132) soft wheat varieties grown in cooperative regional trials in the United States in 2009. Quality parameters included kernel hardness, wheat and flour protein, break flour and flour yield, solvent retention capacity (SRC), and cookie diameter. High levels of variation were observed among varieties, regions, and environments. Four separate nurseries were used to grow the varieties: Uniform Eastern & Southern Soft Red Winter Wheat Nurseries (East SRW, South SRW), and the Western Regional Soft White Winter & Spring Wheat Nurseries (West SWW, West SWS). Across all nurseries, location influenced milling characteristics more strongly than did variety, but variation in baking characteristics was dominated by varietal differences. Nursery mean cookie diameter was the highest in the East SRW nursery (9.36cm), and smallest in the West SWW nursery (9.25cm), which also had the hardest kernels by a large margin (23.6 vs. 34.8). Notably, the East SRW nursery exhibited the highest sucrose SRC (95.0%), whereas the West SWW nursery displayed a markedly lower sucrose SRC response (90.7%). The influence of variety and location differed among nurseries and measured characteristics. Based on baking characteristics, the rank of nursery performance was: East SRW, South SRW, West SWS, and West SWW, which tended to correspond to kernel hardness, flour protein, and break flour yield trends.