Evaluation of Milling and Baking Quality QTL in a AGS 2000 x NC-Neuse Soft Red Winter Wheat Population.

Milling and baking characteristics of wheat are controlled by a number of genetic factors. While genes governing grain hardness and glutenin/gliadin content have been identified and account for much of the differences between classes of wheat, significant differences within classes remains to be explained. The objective of this study was to identify genetic components contributing to this variation within a soft red winter wheat population.This study used a population of recombinant inbred lines (RILs) from the cross between AGS2000 and NC-Neuse. Ten milling and baking quality parameters were assessed at a total of six environments: grain protein, flour protein, lactic acid solvent retention capacity, sucrose solvent retention capacity, cookie dough extensibility, grain hardness, flour yield, softness equivalence, modified milling quality, and modified baking quality.  A map containing 1800 molecular markers covering twenty seven linkage groups was used. Phenotypic data was compared to this map using composite interval mapping (CIM) to identify putative quantitative trait loci (QTL).  Significant differences were observed between the parents at the p < 0.01 level for all traits except GP (0.52) and FP (0.44). An average of about 4 QTL were discovered for each trait within each environment.  For all traits, two to four QTL mapped to the same locus in at least 3 environments. The average proportion of variability explained by these QTL across reps ranged from 32% (GP) to 51% (LASRC).  Large effect QTL (at least R² = 0.10) were identified for GH and FY on chromosomes 1B and 5B, indicating potentially novel loci which influence milling quality.  Additionally, QTL overlapped on chromosomes 1B, 2B, and 7A for FP and GP. Of these, the QTL at 1B and 7A coincided with QTL for MBQ, indicating the importance of these for flour baking quality. QTL were mapped to 5A and 7A for both CD and SE. The recurrence of QTL at the 7A locus indicates that this region plays and important role in determining baking quality among soft red winter wheats.