Soybean [Glycine max (L.) Merr.] is an important source of protein and vegetable oil. Genetic improvement of soybean seed yield and composition are ultimate breeding goals. During the past 80 yr, breeders have selected for high yield and other desired traits to make genetic improvements. To quantify the genetic changes to seed yield, yield stability, and other important agronomic and end‐use quality traits, we evaluated 93 soybean cultivars in Maturity Groups (MG) V, VI, and VII that were released from 1928 to 2008. Replicated yield trials specific for each MG set of cultivars were conducted during 2010 to 2011 in a total of 27 southeastern US year‐location environments. A mixed linear model was used to calculate best linear unbiased predictors (BLUPs) for each cultivar for each measured trait within each MG. Regressed cultivar effect BLUPs of each trait by year of cultivar release revealed positive linear trends for annualized genetic yield gains of 17.6, 13.5, and 10.3 kg ha−1 yr−1 for MG V, VI, and VII, respectively. Averaged across MGs, the annualized rate of genetic gain was estimated to be 13.7 kg ha−1 yr−1. Yield stability analyses revealed significant differences in regression coefficients (b), which were >1.0 for newer cultivars but <1.0 for older cultivars. Overall, the average annualized rate of genetic gains for seed yield reported herein are equivalent to those previously reported, indicating that a yield plateau has not been reached for MG V, VI or VII soybean cultivars.

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Durum wheat (Triticum turgidum ssp. durum) is considered unsuitable for the majority of commercial bread production because of its weaker gluten strength, combined with a larger flour particle size and higher level of starch damage after milling. Recently, a new durum cultivar with soft kernel texture, Soft Svevo, was developed by the Ph1b‐mediated homoeologous transfer of the Puroindoline genes at the Hardness (Ha) locus from the D genome of T. aestivum L. The objective of this research was to evaluate the dough strength and pan bread‐making potential of soft‐kernel durum germplasm developed from crossing Soft Svevo to selected entries of the International Maize and Wheat Improvement Center (CIMMYT) 44th International Durum Yield Nursery. Forty‐six F2:5 soft durum full and half‐sib lines were grown in replicated plots in two locations. Grain samples were evaluated for flour protein quality, dough mixing, and strength characteristics and bread baking. Significant differences (p < 0.05) were detected among lines for flour sodium dodecylsulfate (SDS) sedimentation volume (3.2–12.6 mL g−1), solvent retention capacity lactic acid (63.2–112.6 g 100 g−1), Mixograph water absorption (59.8–64.5 g 100 g−1), peak height (37.1–52.8), and peak width (55.4–125.2), and loaf volume (629–864 cm3).These results indicate that the bread‐making potential of soft durum can be improved if hard durum cultivars with favorable alleles for protein quality, dough strength, and bread making are chosen as crossing parents with Soft Svevo and, by extension, other soft‐kernel durum wheat germplasm.

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The durum wheat (Triticum turgidum ssp. durum (Desf.) Husn.) cultivar Soft Svevo with a soft kernel texture was developed through a Ph1b-mediated homoeologous 5DS-5BS chromosomal translocation. The soft kernel trait (Hardness locus) derived from chromosome 5D of the common wheat (Triticum aestivum L.) cultivar Chinese Spring. Soft Svevo was used as the donor parent to create near-isogenic soft durum germplasm. The size of the translocation, its estimated breakpoint, and the amount of chromosome 5BS translocated, if any, remain unknown. Four near-isogenic pairs of hard and soft kernel durum genotypes, in addition to Soft Svevo and the Chinese Spring deletion line 5DS-2, which lacks a distal 22% terminal segment of chromosome 5DS, were genotyped using Illumina's 90k wheat single nucleotide polymorphism array. Single nucleotide polymorphism results were processed in GenomeStudio and 164 polymorphic markers were identified between the near-isogenic lines (NILs). Subsequent BLASTn results for two subsets of markers corresponding to the distal ends of chromosomes 5DS and 5BS indicated that the translocation event was nearly reciprocal, as a ~24.36-Mbp segment of chromosome 5DS was gained, whereas a ~20.01-Mbp segment of chromosome 5BS was lost. Genomic in situ hybridization images of the soft durum NILs agreed with these estimates and confirmed the absence of additional terminal or interstitial translocations. Soft durum represents the potential of a new wheat market class and these findings will assist durum wheat breeders in the development of new soft durum germplasm.