Inheritance of seed zinc accumulation in navy bean

Human zinc (Zn) deficiency is a widespread condition prevalent in people consuming grain and legume based diets. Dry beans (Phaseolus vulgaris L.) are frequently the major protein source in such diets. One way to reduce the incidence of Zn deficiency may be through the development of high Zn dry beans. Large variation for dry bean seed Zn concentration exists, which would aid in the development of Zn-rich cultivars. The objectives of this study were to determine the inheritance of seed Zn levels in navy bean and to measure seed phytic acid (PA) levels in relationship to seed Zn concentration as an indicator of Zn bioavailability. A high seed Zn cultivar 'Voyager' and a low seed Zn cultivar 'Albion' were used to create the F-2 and backcross populations that were field grown in 1999 and 2000. Seed Zn was measured in both years and seed phytic acid was measured in 1999. The results of this experiment suggest that a single dominant gene controls the high seed Zn concentration in the Voyager/Albion cross. In addition, phytic acid levels between the parent cultivars used in this study showed little variability and there was no strong correlation between seed Zn and PA concentrations. The development of dry bean cultivars with increased seed Zn levels should be possible through breeding.