Inheritance of Seed Mineral Concentration in Common Bean.

Micronutrients are essential elements needed in small amounts for adequate human nutrition and include the elements iron and zinc. Both of these minerals are essential to human well-being and an adequate supply of iron and zinc help to prevent iron deficiency anemia and zinc deficiency, two prevalent health concerns of the developing world. The objective of our research has been to determine the inheritance of seed iron and zinc accumulation thorugh QTL anlayses with crosses of low × high mineral genotypes. One important population (DO364 x G19833) was grown over two trial sites and analyzed with two analytical methods (Inductively Coupled Plasma Spectrometry and Atomic Absorption Spectroscopy) to determine iron and zinc concentration in the seed harvested from these trials. The variability in seed mineral concentration among the lines was larger for iron (40.0-84.6 ppm) than for zinc (17.7-42.4 ppm) with significant correlations between trials, between methods and between minerals. A total of 26 QTL have been identified so far for the mineral × trial × method combinations of which half have been for iron concentration and half for zinc concentration. Many of the QTL for both iron and zinc cluster on the upper half of linkage group B11, explaining up to 47.9% of phenotypic variance, suggesting an important locus useful for marker assisted selection. Other QTL were identified on linkage groups B3, B6, B7, and B9 for zinc and B4, B6, B7, and B8 for iron. The relevance of these results for breeding common beans will be discussed especially in light of crop improvement for micronutrient concentration as part of a biofortification program.