Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 9/8/2014
Publication Date: N/A
Interpretive Summary: Gossypol is present in all parts of the cotton plant including leaves and seeds, and it is poisonous to insects and animals. The presence of gossypol in the seed prevents cotton seed, a rich source of protein, from being used as a food source. It has not been possible to produce cotton varieties without gossypol (in both seeds and leaves) that can produce reliable high-yielding crops. This chapter discusses three methods that have been used in an effort to produce cotton plants with normal leaf gossypol and low seed gossypol, so that the seed can be used as a food source. As a result of this research, it is now possible to use a combination of traditional breeding and molecular biology to create new cotton varieties that meet the requirements of cotton growers for low seed gossypol plants. This will in turn increase the uses for cottonseed meal.
Technical Abstract: Cottonseed represents an enormous source of vegetable protein that could be used to help alleviate hunger especially in developing countries. Increasing the value of cottonseed would also be a boon for the U.S. cotton industry. Gossypol is the major impediment to minimizing the cost of cottonseed processing and maximizing its utilization. However, it was proven decades ago that simply eliminating gossypol from cottonseed by planting glandless cultivars leads to devastating yield losses due to insect and animal attack. As the major source of income for the producer is first fiber yield and second fiber quality, the simplistic approach to increasing cottonseed utilization via removal of gossypol from the plant is not the answer. This chapter discusses several strategies that are being used to selectively reduce or eliminate gossypol from the seed without affecting gossypol in the foliage. One is the utilization of exotic germplasm to selectively reduce total gossypol in the seed. The second is to incorporate the low (-)-gossypol seed trait from Moco cottons into commercial cottons. The third strategy is to modify enzymes and genes involved in the biosynthesis of gossypol and related terpenoids that protect the plant from diseases and insects to achieve protection for the plant and low gossypol for the seed. With a multi-prong approach, the goal of lowering the gossypol content in cottonseed without detrimentally affecting plant performance can be achieved and the utilization of cottonseed maximized.