Inheritance of the number of ray flowers in sunflower

Abstract The number, shape, size and color of the sunflower ray flowers are widely used as marker traits in hybrid seed production, for identification of genotypes, in ornamental floriculture. However, there is not enough information about the genetic control of these traits. The inheritance of the number of ray flowers and their absence on inflorescences was studied in cultivated sunflower. In the first case, two inbred lines of mutant origin with a contrasting manifestation of the studied trait were crossed. The F1 hybrid held an intermediate position between the parents, but approached the parental line with a large number of ray flowers. The average value of the number of petals in F2 was close to F1. The study of segregation in F2 showed that the trait “number of ray flowers” is inherited polygenically and controlled by three pairs of non-allelic genes with additive effects. The inheritance of the absence of ray flowers was studied by crossing a line with petals and an apetalous accession. F1 hybrid showed ray flowers, and in F2, segregation close to 42 (with ray flowers): 22 (without ray flowers) was observed. This implies participation of three non-allelic genes in the control of this trait, one of which in a recessive state suppresses the action of two other recessive genes. The revealed patterns of inheritance expand the information in the field of private genetics of sunflower and allow performing more purposeful breeding of this crop.