Influence of homoeologous chromosomes on gene-dosage effects in allohexaploid wheat (Triticum aestivum L.).

Gene-dosage responses for a group of six wheat endosperm proteins have been investigated by using compensated nulli-tetrasomic lines of cv. Chinese Spring. Practically linear dosage responses have been observed for all the proteins. However, for two of the proteins (and probably for a third one), the net output of protein, at each dosage of its structural gene, was 30-80% higher when the chromosome carrying an active homoeogene was absent. The possible significance of this effect in connection with the loss of gene redundancy undergone by polyploids is discussed.