Gene effects and heterosis for grain Fe and Zn content in barnyard millet (Echinochloa frumentacea (Roxb.) link)

Barnyard millet (Echinochloa frumentacea) is an unexplored nutri-rich crop that thrives well in harsh environments and supports many small farmers in Southern and Eastern Asia. Although it has rich sources of micronutrients, the genetic studies are very limited which further impedes in its genetic improvement. Therefore, we attempted to assess the genetic diversity for Fe and Zn content in 40 barnyard millet germplasm and to evaluate the combining ability and heterosis in sixteen F1 cross combinations through line × tester model. The Mahalanobis D2 analysis grouped the 40 genotypes into nine different clusters. Cluster III and I were the largest groups containing 22 and 6 genotypes, respectively and the rest of seven clusters were the lowest group containing one or two genotypes. Positive correlation was observed between Fe and Zn content though both had a non-significant association with grain yield. This indicate that there would not be any compromise on increase or decrease of grain yield while breeding for varieties high in micronutrient content. Combining ability analysis revealed that lines, testers, and their interaction components are significant. The predictability ratio indicated the predominance of additive variance for Fe and Zn content and non-additive variance in the inheritance of yield components. Genotypes, ACM 331, ACM 333, ACM 335 and MA 10 exhibited positive gca effects for Fe and Zn content and grain yield. Two cross combinations, ACM 331 × ACM 335 and ACM 331 × MA 10 involved one or both the parents with good gca effects exhibited, high mean, positive mid-parent heterosis and sca effects for Fe, Zn content and yield components. Thus, the present investigation provided a significant understanding of the gene action and the possibility of utilizing the selected parents and cross combination for exploiting micronutrient traits in barnyard millet crop.