Inheritance of Flower Type and Doubleness in China Aster

The inheritance of flower doubleness and flower types in China aster was studied in 7 crosses involving 9 parents. Flower doubleness (DD) was observed to be monogenically dominant over singleness (dd). Pompon flower type with one row of ray florets and tubular disc florets was dominant over both chrysanthemum and fluffy types, while chrysanthemum type was dominant over fluffy type. Three independent genes Tu, D and C were found to govern these three different flower types. Another genotype having pompon flower type with four rows of ray florets and tubular disc florets was dominant over pompon with one row of ray florets and tubular disc florets. When this pompon type was crossed with chrysanthemum and fluffy types, it was found that the tubular (showy) disc florets were incompletely dominant over normal (non-showy) disc florets. Thus, in this pompon type, there is a dominant allele C’ of the gene C which does not allow the conversion of ray florets into tubular disc florets. Tu alone or C or C’ alone fail to produce tubular disc florets.