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

Authors: Erpelding, John

Submitted to: Plant Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/4/2020
Publication Date: 2/22/2021
Citation: Erpelding, J.E. 2021. Genetic characterization of the red colored corolla phenotype for Gossypium arboreum accession PI 529731. Plant Breeding. 140:142-149. https://doi.org/10.1111/pbr.12884.
DOI: https://doi.org/10.1111/pbr.12884

Interpretive Summary: Flower color is an important trait for the identification and evaluation of genes controlling pigment production in plants. Most Asiatic cotton (Gossypium arboreum) varieties conserved in the United States Department of Agriculture germplasm collection showed yellow flowers. Cotton varieties with red flowers are rarely observed, but the red flowered variety PI 529731 was identified from the Asiatic germplasm collection. To determine the genetic inheritance of red flower coloration, PI 529731 was crossed with two white flower Asiatic cotton varieties (PI 529729 and PI 529740) and flower color in the resulting progeny was recorded. These progeny showed variation in flower color including dark red, red, light red, white, yellow, and white flowers with red colored petal margins. Analysis of flower color data showed that red coloration of flowers was controlled by a single dominant gene, that yellow flower coloration was controlled by a different single dominant gene, and that both of these genes were required for the development of red flowers observed in PI 529731. In addition to flower color, red coloration can be observed in other parts of the cotton plant and has been associated with insect resistance and stress tolerance. The populations and results from this study can be used for further research to evaluate the genes controlling pigment production in flowers and this information can be used to evaluate pigment development in other parts of the plant for cotton improvement.

Technical Abstract: Flower corolla color is an important trait for the attraction of pollinators and for the horticultural industry. Gossypium arboreum accessions from the United States Department of Agriculture germplasm collection more frequently show flowers with a yellow colored corolla. Accession PI 529731 is unique in that the flowers have a red colored 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 generation suggesting a dominant trait. Variation in corolla color was observed for plants in the F2 populations including dark red, red, light red, white, yellow, and white with petals having red colored margins. These data supported a single dominant gene conferring the 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 supported 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.