Effect of autopolyploidy on quantity and quality of protein in barley

The range and mean protein content of autotetraploids of high-lysine Notch-2 mutants of barley were consistently higher than the diploids in C3 and C4 generations of colchicine treated seeds. Amino acid analysis of whole grain meal of diploid Notch-2 and one strain of its autotetraploid revealed differences in the amino acid composition. The proportion of albumin in the diploid and the autotetraploid Notch-2 was higher by 21% and 45% respectively, in comparison to the parent 'N.P. 113', whereas the glutelin fraction was significantly higher in the autotetraploid. The autotetraploid, with increased glutelin and decreased prolamin, showed no increase in lysine. It is possible that the recessive high-lysine gene may be lacking dosage effect, resulting in no increase in lysine in the autotetraploid, whereas protein content, a polygenically controlled trait, is enhanced due to genome duplication.