Submitted to: Journal of Cotton Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/16/2010
Publication Date: 4/1/2010
Citation: An, C., Jenkins, J.N., McCarty Jr., J.C., Saha, S. 2010. Atypical Ligon Lintless-2 Phenotype in Cotton. Journal of Cotton Science. 14:13-16. Interpretive Summary: A short lint fiber length cotton plant mutant Ligon lintless 2, designated Li2 Li2, was grown in Mississippi field plots and several plants were observed that produced two lint fiber length phenotypes on the same plant. These phenotypes were the typical short lint fiber length expected for the mutant and normal lint fiber length which was not expected for the mutant. Bolls of three of these plants were harvested according to the lint length phenotype and planted the following season. They did not breed true to phenotype but continued to produce plants some of which were short lint expected for the mutant and some had short lint fiber length and normal lint fiber length bolls on the same plant. Some plants were ratooned and transferred to the greenhouse where they continued to produce both lint phenotypes on the same plant. We propose that plants with the two seed lint length phenotype are most likely due to incomplete penetrance or lack of expressivity of the dominant gene Li2 Li2 at our location in Mississippi.
Technical Abstract: The mutant Li2 is reported to be a dominant single gene mutation in cotton, Gossypium hirsutum L. It has normal vegetative phenotypic morphology and the phenotype of the seed cotton is reported to be fuzzy seed with short fibers. The objective of this research was to report on atypical phenotypes observed in field grown plants in two different years. Several plants, with the genotype of Li2 Li2 were discovered that expressed two seed cotton phenotypes on the same plant. In addition some plants expressed a near normal seed cotton phenotype. Most plants expressed the typical phenotype with short fibers. Three plants with two seed cotton phenotype on the same plants were harvested according to seed cotton phenotypes and planted the following year. For plants from seed harvested from branches with short fibers and plants from seed harvested from branches with normal length fibers, each failed to breed true to fiber phenotype in the following generation, i.e. plants from seed with short fiber and plants from seed with long fiber each produced some short fiber phenotypes. However, each seed cotton phenotype also produced some plants with both fiber phenotypes on the same plants and some plants with only normal length fiber phenotype. Some of the plants with two phenotypes on the same plant were ratooned and transferred to the greenhouse where they continued to produce two phenotypes on the same plant. We propose that plants with this atypical seed phenotype are most likely due to incomplete penetrance or lack of expressivity of the dominant gene Li2 at our location in Mississippi.