Environmental and genetic variation for protein content in winter wheat (Triticum aestivum L.)

Summary There is a considerable amount of variation in the protein content of wheat kernels. This variation may be induced by environmental factors, but can also be attributed to genetic differences. Within a genotype the correlation between grain yield and grain protein content can be either close to zero, positive, or negative. depending on the fertility level. Between genotypes this correlation is strongly negative. It is argued that the negative inter-genotypic correlation is largely a consequence of the high harvest-index of high yielding varieties. Breeding methods to alleviate the negative yield-protein content relationship are given.