Genetic characterization of the red coloured corolla phenotype for Gossypium arboreum accession PI 529731

Abstract

AbstractFlower corolla colour is an important trait for the attraction of pollinators and for the horticultural industry. Gossypium arboreum (L.) accessions from the United States Department of Agriculture germplasm collection frequently show flowers with a yellow coloured corolla. Accession PI 529731 is unique in that the flowers have a red coloured corolla. Genetic characterization of corolla pigmentation was conducted by crossing PI 529731 with two white flower accessions. Flowers with a red corolla were observed in the F1 generations suggesting a dominant trait. Variation in corolla colour was observed for plants in the F2 populations including dark red, red, light red, white, yellow and white with petals having red coloured margins. These data support a single dominant gene conferring the four red corolla phenotypes. The yellow corolla phenotype also supported a single dominant gene model. Dominant alleles at both loci are required for expression of the PI 529731 phenotype and data support a two gene model with a 9:3:3:1 segregation ratio. These data are useful for the characterization of genetic mechanisms controlling tissue‐specific pigmentation.