Unraveling the genetics of calcium content in finger millet grains through association mapping

Combating mineral deficiencies has been a major challenge for agricultural scientists world over. Lack of calcium in diets could be overcome through biofortifying food crops especially cereals. Finger millet (Eleusine coracana) grains are highly rich in calcium, therefore in the present study this phenotypic trait was explored using association study on a natural population of finger millet. A total of 238 accessions of finger millet were analysed using 85 simple sequence repeats (SSR) markers. SSR profiles generated 160 alleles and 20 primer pairs which were polymorphic across the population with 0.14 to 0.78 polymorphic information content. Grain Calcium content (GCC) varied from 72 to 452 mg/100g seed. Two accessions, GPHCPB45 (452.8 mg) and GPHCPB 439.8 mg) each from Northern India and exotic areas were found with highest GCC. Association analysis through the general linear model in TASSEL software detected two markers UGEP78 and UGEP60 in significant association (P less than 0.001) to calcium content. The molecular marks, UGEP60 can be a potential marker with phenotypic variance amounting to 13.8%. However, the mixed linear model did not detect any significant associations probably because of low polymorphism within the finger millet collection considered in this study. Identification of two accessions with higher calcium content may be useful in finger millet improvement.