Submitted to: Plant Breeding
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/11/2008
Publication Date: 12/1/2009
Citation: Romano, G.B., Scheffler, J.A. 2009. Lowering Seed Gossypol Content in Glanded Cotton (Gossypium hirsutum L.) Lines. Plant Breeding. 127(6):619-624 Interpretive Summary: Cultivated cotton contains a chemical called gossypol that helps protect the plant from insects and disease. Unfortunately gossypol can be detrimental to humans and animals. Cotton seed could be a valuable source of high quality protein for animal feed if the gossypol can be reduced. New cotton lines with low gossypol in the seed and high fiber quality were developed. Using these lines, it will be possible to double the amount of whole cottonseed in a dairy cow ration without causing any detrimental effects. It may also be possible to include these in fish or poultry feed. These lines were developed using conventional breeding techniques and are not genetically modified organisms (GMOs).
Technical Abstract: Cottonseed is a rich source of oil (ca. 21%) and high quality protein (ca. 23%) but its value as food and feed is limited by the presence of gossypol, a toxic polyphenol contained in glands located throughout the plant. Glandless cotton cultivars have been developed, but they were unsuccessful commercially because the gossypol in the glands also protects the plant from pests. An alternative strategy for selection was adopted in this breeding program which minimizes gossypol content in seeds while still maintaining glands throughout other plant organs. Parents from glanded adapted lines (STV 7A, JaJo 6078, Acala ‘Maxxa’, A1006) were crossed with a glandless parent (STV 7A gl). F7 and F8 progeny were evaluated visually for presence and abundance of glands in vegetative and reproductive organs and analyzed with HPLC for percent total gossypol in the seed. The correlation between seed gossypol content and boll glanding was moderate enough in all populations to allow selection of genotypes with seed gossypol reduced by 50% to 80% compared to the glanded parent. These lines have normal glanding on stems and stigmas and near normal glanding on the bolls and calyces. Leaves show a reduction in gland numbers from the onset of flowering through maturity, but retain glands on the veins and leaf margins throughout the season. These new lines should allow the doubling of whole cottonseed in feed for ruminant animals without detrimental effects. It might also be possible to include cottonseed in fish or poultry rations, further expanding the use of cottonseed meal.