Inheritance of electrophoretic variants of tuber proteins in Solanum tuberosum haploids.

Soluble tuber proteins were separated by discontinuous polyacrylamide gel electrophoresis on vertical slabs. Banding patterns of proteins stained with Coomassie Blue in 7.5% acrylamide gels (pH 4.3) were few and distinctive for haploids (2n = 2x = 24) derived from several cultivars (2n = 4x = 48). Katahdin and Chippewa haploids have only three different banding patterns for the eight fastest moving bands. The haploids have either the parental pattern (all eight bands) or one of two complementary banding patterns (four bands). The frequency of these patterns among the haploids indicates that the eight bands are controlled by one locus which is duplex (A1 A1 A2 A2) in the parents. Haploids with the genotype A1 A2 have eight bands. A1 A1 haploids have four bands, and A2 A2 have the other four bands. Tawa haploids have in equal numbers either the eight (A1 A2) or four (A2 A2) band pattern. Thus the genotype of Tawa is A1 A2 A2 A2. The control of four bands by one allele could be explained by assuming that these alleles are involved in posttranslational modification or assembly of one or two protein species. Another explanation is that pseudoalleles or redundant genes produce the groups of protein bands. The eight proteins studied apparently are of similar molecular weight but differ in charge.