Author
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Hosfield, George |
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Submitted to: Bean Improvement Cooperative Annual Report
Publication Type: Review Article Publication Acceptance Date: 3/1/2001 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Since the beginning of the Twentieth Century, extensive research has been carried out on the inheritance of seed coat color in common bean (Phaseolus vulgaris L.). Eight Mendelian loci contribute to color synthesis. The determiner, P, does not produce any color in itself but must be present for pigment formation in the seed coat to be possible. The genetic factors, C, ,D, and J are color genes and are only expressed in the presence of P. The genes, G, B, V, and Rk are modifying genes that intensify pale colors formed by the action of the color genes but do not impart color in themselves. The biochemical effects of the eight genes involved in seed coat color of bean are currently not well understood; however, the compounds that impart color are anthocyanins, flavonol glycosides, and leuco-anthocyanidins. These pigments belong to a class of secondary plant metabolites known as flavonoids. Flavonoids have antioxidant properties which can render come cancer-causing agents in the body ineffective. Pharmaceutical companies may be interested in the flavonoids present in bean seed coats because these compounds could be extracted from surplus or split beans, packaged in tablet form, and marketed as health-promoting food supplements. Flavonoids in common bean gives rise to the "bean paradox". The paradox exists because, on one hand, seed coat flavonoids promote health and well-being as antioxidants, but, on the other hand, reduce bean seed digestibility and impair nutrient bioavailability by complexing with protein and other seed macromolecules. Balancing the health promoting benefits of flavonoids in bean seed coats with their antinutritional effects in plant improvement programs provides an interesting challenge to the plant breeder. |
