Genetic Analysis in Nicotiana alata: The Inheritance of Flower Doubleness

Genetic analysis of a white double-flowering Nicotiana alata is being investigated. Self-pollination of the double-flowering plant produced all double progeny. Reciprocal hybridization of the double-flowered selection with N. alata cultivars produced nondouble F 1 progeny that segregated 3:1 (nondouble to double) in the F 2 generation. Reciprocal backcrosses of F 1 plants to the parents resulted in nondouble progeny when backcrossed to the nondouble parent and 1:1 segregation when backcrossed to the double parent. Intercross of F 1 plants resulted in progeny segregating 3:1. Double flowering habit has been transferred to white, red, salmon, green, and bicolor N. alata . Results suggest double flowering is under nuclear control regulated by a recessive allele.