Genetic mapping of a chickpea ( <i>Cicer arietinum</i> L.) diversity panel for mineral biofortification towards human nutrition

Chickpea (Cicer arietinum L.) is a cool-season legume with low fats and high concentrations of protein, carbohydrates, and minerals. As such, chickpea can contribute to alleviate hidden hunger due to mineral deficiencies and malnutrition, particularly in Asian and African countries. A chickpea germplasm panel composed of 256 accessions with both desi and kabuli types was evaluated for calcium (Ca), potassium (K), magnesium (Mg), phosphorus (P), copper (Cu), iron (Fe), manganese (Mn), selenium (Se), and zinc (Zn) concentrations. High mean concentrations were found for Ca (181.2 mg/100 g), K (971.9 mg/100 g), Mg (135.2 mg/100 g), P (383 mg/100 g), Cu (0.73 mg/100 g), Fe (5.3 mg/100 g), Mn (4.1 mg/100 g), Se (0.01 mg/100 g), and Zn (2.41 mg/100 g), with a broad concentration range and high percent recommended daily allowance noted for each element. Significant positive correlations were found among all minerals except for a negative correlation between Ca and K. Genomic association mapping detected a total of 14 single-nucleotide polymorphisms (SNPs) for Ca, Mg, P, Mn, and Zn. The candidate genes associated with these SNPs are pivotal to physiological pathways for plant stress response, health, and ionic homeostasis. Admixture analysis found nine diverse subpopulations in the panel based on ancestral diversity. Principal component analysis revealed population structure consistent with admixed ancestral subpopulations, chickpea types, and country of origin. Together, these findings show chickpea mineral biofortification can be achieved using genomic techniques and classical approaches to breed for high mineral concentrations to improve human health and plant defense.