Genotypic Variability in Calcium Concentration of Peanut (Arachis hypogaea L.) Seeds

Abstract

Leaf spots are devastating diseases of peanut worldwide. The University of Florida peanut (Arachis hypogaea L.) breeding program has developed cultivars with superior resistance to leaf spot diseases, but their production was limited by poor field emergence. One factor that is believed to be related to emergence of resistant cultivars is reduced accumulation of seed Ca. The goal of this study was to compare the seed Ca concentrations of resistant genotypes to susceptible genotypes and to assess the genetic variability for seed Ca accumulation in commercial peanut germplasm. Seed Ca concentrations were measured for 51 genotypes that were diverse for market class, maturity, resistance to leaf spot, and genetic background. Genotypes were placed into categories based on seed size and maturity: Large seeded genotypes (“Virginias”), small seeded with medium maturity (“Medium”), and small seeded, late maturing (“Late”) which contained the resistant genotypes. For each of these groups, the seed Ca concentration was calculated and heritability of Ca concentration was determined for each group. Late maturing runners (those with the highest resistance to leaf spot) had the lowest seed Ca concentration followed by the medium maturing runners, and then the large seeded Virginias. The broad‐sense heritability estimate for seed Ca concentration was 0.33 and estimates were 0.26, 0.19, 0.41 for the Late, Medium, and Virginia groups, respectively. These results suggest that seed Ca concentration can be improved through breeding, which may allow for the development of cultivars with leaf spot resistance and commercially acceptable seed vigor.