Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 6/5/2000
Publication Date: N/A
Interpretive Summary: For an indeterminate period of time following harvest, potatoes will not sprout and are physiologically dormant. Dormancy is gradually lost during postharvest storage and the resultant sprouting is detrimental to the nutritional and processing qualities of potatoes. Because of this, sprouting results in severe financial loss to producers. Currently sprouting is controlled through the use of synthetic sprout inhibitors. The research being conducted in this lab is directed towards 1.) identifying key physiological processes that naturally regulate tuber dormancy and, ultimately, 2.) modifying these processes genetically thereby eliminating the need for artificial sprout suppression. Much of our current research concerns the roles of plant hormones in the regulation of tuber dormancy. In this chapter, the roles of endogenous hormones in the regulation of tuber dormancy are reviewed and critically assessed. To date, only two classes of naturally occurring hormones (abscisic acid and ethylene) have been proven to play a role in dormancy regulation in tubers. Recent research has implicated a third class (the cytokinins) as possible natural dormancy terminating agents. The involvement of the remaining naturally occurring hormones remains unproven and awaits further experimentation. A more complete understanding of the roles of the naturally occuring plant hormones in tuber dormancy regulation and the internal mechanisms controlling their synthesis and action will greatly speed the processes of improving the activity of current sprout control agents and identifying new sprout control agents/technologies.
Technical Abstract: Indigenous to Central and South American, the potato (Solanum tuberosum L.) was initially domesticated by pre-Columbian Indians and has been extensively cultivated since that time. In terms of total production, the potato ranks among the top four food crops and in many countries, constitutes a major source of human nutrition. Global production of potatoes exceeds 290 million metric tons (FAO estimate). Annual production in the United States exceeds 498 million hundred-weight (1996 USDA estimate). Over 70% of the total U.S. potato crop is placed in short to long term storage for a stable year-round supply. Unlike many crops, potatoes are stored in a fully hydrated and highly perishable form. As such, postharvest losses from both physiological and pathological processes can be severe. Of the physiological processes that affect the quality of stored potatoes, one of the most important is postharvest sprouting. In this chapter, the roles of endogenous hormones in potato tuber dormancy regulation are critically evaluated and areas requiring further research are identified.