From a nutritional and health point of view, Foxtail millet (Setaria italica [L.] P. Beauv.) is one of the valuable millets due to its adaptability to adverse environmental conditions and ideal characteristics for functional genomics studies. Despite the increased number of studies on foxtail millet globally, however, presently in Indonesia, it is an underutilized crop species. Through conventional hybridization, combining superior traits has been conducted to produce high-yielding cultivars with early maturity and medium plant stature in foxtail millet. The pertinent study aimed to elucidate the genetic diversity in F₂ populations derived from the cross of Botok-10 × ICERI-5 and approximate the broad-sense heritability and gene actions controlling various traits in foxtail millet. The study’s genetic material used 352 F₂ populations from the crossing of two potential parental genotypes of the foxtail millet: Botok-10 and ICERI-5. The results enunciated several individual F₂ populations with medium plant stature and earlier heading time compared with the parental genotypes. These potential F₂ segregants were also higher yielders than the male parent (ICERI-5). Non-additive gene action controlled the inheritance of the three targeted traits, i.e., plant height, heading time, and grain weight per plant in the foxtail millet. The heading time and grain weight per plant traits showed the highest genetic coefficient of variation (GCV) and moderate broad-sense heritability, and the plant height showed moderate GCV and low broad-sense heritability in the foxtail millet. All observed traits, except stem diameter, showed a significant positive correlation with grain weight per plant. The selection differential values indicated that the selected individuals have faster heading time and higher grain weight per plant than the overall F₂ populations.

Keywords: Foxtail millet (Setaria italica L.), broad-sense heritability, gene action, kurtosis, skewness, underutilized crops

Key findings: The promising F₂ segregants derived from the cross, Botok-10 × ICERI-5, met the breeding objectives like medium plant stature, early heading, and high productivity in foxtail millet. All the vital traits were under the control of a non-additive gene action. The heading time and grain weight per plant showed the highest GCV and moderate heritability, and the plant height showed moderate GCV and low heritability.