Genetic analysis of the Asiatic cotton (Gossypium arboreum) petal spot phenotypes

Abstract

AbstractThe cotton species Gossypium arboreum L. is self‐pollinated, and most accessions in the United States Department Agriculture, National Plant Germplasm System, produce flowers with red pigmented petal spots, which represents the primitive phenotype and more attractive to pollinators. Few accessions have the ghost spot phenotype, and genetic analysis of this trait was conducted for PI 615742. Two F2 populations were developed by crossing PI 615742 with G. arboreum accessions PI 452097, having red petal spots, and with PI 529708, showing the spotless phenotype. The PI 615742 × PI 529708 population data indicate a single completely dominant gene which confers the ghost spot phenotype. Petal spot phenotypes observed for the PI 615742 × PI 452097 population indicate red pigmented spots are also conferred by a single completely dominant gene. These results support a two‐gene model in which the presence of petal spots and pigment development are controlled by independent genes that co‐segregate with stem pigmentation. The accessions and population data can aid in characterizing the mechanisms controlling floral traits and pigment expression.