DIFFERENTIAL ALLELIC EXPRESSION AT A LOCUS ENCODING AN ENDOSPERM PROTEIN IN TETRAPLOID WHEAT (TRITICUM TURGIDUM)

G. Salcedo ¹, C. Aragoncillo ¹, M. A. Rodriguez-Loperena ¹, P. Carbonero ¹, and F. Garcia-Olmedo ¹

¹ Departamento de Bioquímica, E. T. S. Ingenieros Agrónomos, Madrid-3, Spain

Two hydrophobic endosperm proteins, designated CM3 and CM3', have been purified from appropriate cultivars of tetraploid wheat (T. turgidum) and characterized. They are inherited as though encoded by alleles at a single locus, designated Cm3a and Cm3b, respectively. The net amount of protein molecules has been measured for each of the alleles at one, two and three doses. The amount of CM3' is 50%–65% of that found for CM3. For both, there is a linear gene dosage response. These effects were observed not only in the parental material and the reciprocal F₁ generations, but also in the segregating F₂ generation, indicating that the quantitative difference depends on differences in the structural gene or is controlled by regulatory or modifier gene(s) linked to it.