A selection strategy for combining high grain yield and high protein content in South African wheat cultivars

Grain protein content is a major contributor to nutritional quality of whea t. Due to the negative relationship between yield and protein content, simu ltaneous improvement of these traits is very difficult. The aim of this stu dy was to identify possible selection criteria to improve protein content a nd yield simultaneously. Six spring irrigated wheat cultivars were used as parent lines in a half diallel design. The F1 hybrid progeny and parents we re used as experimental material. Both high and low protein wheat types tra nslocated equal amounts of nitrogen to the grain. Phenotypic correlations r e-emphasised the problems of simultaneous improvement-of grain yield and pr otein content. The use of correlated response gave a better solution. If gr ain protein yield (highly significantly correlated with grain yield), was u sed as selection criterion, even protein per kernel showed a correlated res ponse. It also had a relatively high narrow sense heritability. Grain prote in yield selection therefore gave the only possible solution towards simult aneous improvement of grain yield, and grain protein content.