Seed‐Zinc Concentration and the Zinc‐Efficiency Trait in Navy Bean

Some navy bean ( Phaseolus vulgaris L.) cultivars are susceptible to Zn deficiency. Norstar and Voyager are examples of Zn‐efficient cultivars; Avanti and Albion are examples of Zn‐inefficient cultivars. The objective of this study was to compare growth and Zn accumulation, especially in seed, of these four cultivars. In field and greenhouse experiments, except under extremely low soil‐Zn levels, the two Zn‐efficient cultivars contained >25% higher seed‐Zn concentrations than did the two Zn‐inefficient cultivars. Both Albion and Avanti, but not Norstar and Voyager, were Zn deficient at a field site with a relatively high level of Zn (1.7 mg kg −1 ) extractable by diethylenetrinitrilopentaacetic acid (DTPA). The Zn‐efficiency trait was associated with higher levels of Zn in plant tops and was not associated with differences in P or Fe nutrition. Zinc deficiency delayed pod maturity most in the two Zn‐inefficient cultivars. Analysis for Zn in seed from routine breeder‐yield trials, in which a Zn‐efficient cultivar is not Zn deficient, is proposed as a suitable technique for selecting navy bean genotypes that are both agronomically Zn efficient and better sources of Zn for human nutrition.