Relationship between kernel color and protein content of hard red x hard white winter wheat progeny

Summary

Utilization of high-protein hard red wheat germplasm in breeding high-protein hard white winter wheats for the U.S. Great Plains raised concern regarding possible genetic relationships between kernel color and protein content. Segregating F₃ and F₄ populations from reciprocal crosses and backcrosses involving high-protein hard red winter wheat cultivar Plainsman V and normal-protein hard white winter wheat line KS75216 were examined. Nonsignificant regression and correlation coefficients in the F₃ generations of KS75216/Plainsman V, KS75216//KS75216/Plainsman V and Plainsman V//KS75216/Plainsman V indicated the absence of genetic relationships between kernel color and protein content. Therefore, despite the presence of genes for protein content and kernel color on the same chromosomes (3A, 3B and 3D), kernel color and protein content appeared as independent traits. A small but significant negative relationship between white kernel color and high protein in Plainsman V/KS75216 was attributable to the possible presence of alien genetic material in the parentage of Plainsman V. Chi-square tests indicated that Plainsman V is a mixture of genotypes for kernel color; most genotypes carry two dominant genes for red color and a few carry one or three. Genetic control of grain protein appeared to be complex. Partial dominance for high protein was indicated in the F₃ generation but a generally continuous distribution and transgressive segregation also suggested other genes functioned additively. Heritability estimates by parent-offspring (F₃-F₄) regression were sufficiently high to ensure genetic progress in the selection of high-protein lines in the red x white wheat crosses. We concluded that development of high-protein cultivars is as feasible for white wheats as for red wheats.