Comprehensive evaluation of seed iron content in peanut germplasm and identification of elite genotypes with high iron

Iron is an essential mineral element that plays important roles in plant growth, development, and human health. Peanut is a valuable source of iron for human nutrition. Improving iron content in peanut seeds can enhance both yield potential and nutritional value. In this study, the seed iron content of the 401 peanut germplasm accessions was estimated and substantial variation among these accessions was observed, ranging from 9.02 to 50.60 mg/kg. The seed iron content of valencia type accessions was significantly higher than that of Peruvian , Virginia , and Irregular types. Landraces showed the highest average iron content, followed by advanced cultivars, breeding lines and interspecific hybrid cultivars. Accessions with red seed coat exhibited significantly higher iron content compared with those with pink seed coat. Correlation analysis revealed that the seed iron content significantly negatively correlated with hundred seed weight (HSW), resveratrol and oleic acid. Eight accessions with high iron content were identified with an average iron content of 32.46 mg/kg, including two elite genotypes that Zh.h4280 showed high resveratrol levels (1057.34 ug/kg) and Zh.h1976 exhibited large seeds (HSW over 90g). Association analysis identified four markers, one of which, AHGS2053 stably explained with 5.75%–5.84% phenotypic variation. Accessions containing the favorable allele AHGS2053-250bp exhibited significantly higher iron content compared to those with alternative alleles. The results provide valuable germplasm resources and associated markers for breeding programs targeting high iron content in peanuts.