Changes in yield determinants and quality traits in wheat after 12 cycles of recurrent selection

The objective of this study was to test the genetic response to 12 cycles of a recurrent selection program for grain yield and related traits. During two seasons the 39 S-derived families (three/C 0 –C 12 populations) were evaluated under conventional (CT) and non-tillage (NT) systems. Grain and biomass yield were determined. The grain number per square meter and harvest index were also estimated. Flour protein content, sodium dodecyl sulphate sedimentation, and lactic acid solvent retention capacity were considered as end-use quality predictive tests. High molecular weight glutenin subunits (HMW-GS) variation was also analyzed. A significant increase in grain yield per selection cycle, estimated in 3.25 g m −2 (1.3%) per year, was found under NT, but there was a not significant genetic progress under CT. The decrease in the percentage of protein in the most advanced selection cycles (11.0% vs. 9.7%) did not negatively affect its quality. HMW-GS variation analysis showed the erosion of extreme subunits related to gluten strength. After 24 years of recurrent selection, the grain yield was improved without affecting its industrial quality.