Yield and quality interrelationships amongst random F₃ lines and their implications for wheat breeding

Abstract

The relationship between grain yield and grain quality was studied amongst sets of random Fj lines from seven wheat crosses. The quality measures used included grain hardness, flour yield, flour protein content, farinograph and extensograph properties, and small-scale empirical measures such as Zeleny and sodium dodecyl sulfate sedimentation volume, residue protein content, and Pelshenke fermentation time. A significant negative correlation was found between grain yield and flour protein content. Thus selection for either characteristic would be to the detriment of the other. However, grain yield was not significantly correlated with the other quality measures, indicating that high-yielding, good-quality wheats could be obtained from the population. Most of the small-scale tests were correlated with farinograph and extensograph properties, but the correlation coefficients were not as high as those obtained with varieties or advanced breeding lines. The relationships were not dependent on differences in flour yield, grain hardness or flour protein content, thereby simplifying their application to breeding programs. Concurrent breeding for higher grain yield and improved functional quality would appear feasible. However, flour protein content would, at best, be maintained at current levels as yield increased.