Reselection within population for high grain iron density and its effects on agronomic traits in pearl millet

Abstract

This study aimed to assess whether intra-population selection and its derived lines inter-mating for grain iron (Fe) has any associated changes in grain yield and other agronomic traits in two Open-Pollinated Varieties (OPVs) in pearl millet. The original (C0) and improved bulks (C1) were evaluated in two contrast seasons (referred to as environments). Result showed non-significant differences between C0 and C1 bulks for all the traits except 1000-grain mass in both the populations. This implied that the selection for higher Fe level did not cause any significant changes on grain yield and other agronomic traits. The S1-based random mated bulks are generally more heterozygous as F2 populations, thus, S2-based population improvement would assemble large number of favorable additive allele to elevate Fe and Zn density which did happen marginally in this study. Interestingly, selection for high Fe significantly increased the 1000-grain mass by 4.8% and 14.2% in the AIMP 92901 and ICMR 312, respectively. One cycle of recurrent selection showed marginal improvement for grain Fe and Zn in C1 over C0 bulks of AIMP 92901 (2.4% more Fe and 7.9% more Zn) and ICMR 312 (8% more Fe and 5.4% more Zn). Nevertheless, these micronutrients are being additively controlled so population improvement is possible with increased cycle of selection and subsequent recombination to assemble more favorable alleles for significant difference from its original bulks. Thus, reselection was effective in improving the target traits with no correlated response on the yield traits.