Breeding pearl millet cultivars for high iron density with zinc density as an associated trait
Pearl millet, as a species, has higher levels of iron (Fe) and zinc (Zn) densities than other major cereal crops. However, this study showed the existence of about twofold variability for Fe density (31–61 ppm) and zinc density (32–54 ppm) among 122 commercial and pipeline hybrids developed in India. Thus, there is a need to increase the cultivation of hybrids having higher Fe and Zn levels and enhance their consumption to better address various health problems associated with the deficiencies of these micronutrients. High-yielding open-pollinated varieties (OPVs) and hybrids with higher levels of Fe and Zn densities than those found in most of the commercial cultivars otherwise not bred for these micronutrients as target traits have been developed and are available for commercialization. Breeding lines and germplasm with still higher levels of Fe and Zn densities have been identified. Their utilization in breeding has the potential to enable development of hybrids with >75 ppm Fe density and >55 ppm Zn density. The primary focus of pearl millet biofortification is on improving Fe density with Zn density as an associated trait. Depending on the genotypic composition of the trials, moderate to high correlations between Fe and Zn densities have been observed, indicating good prospects of simultaneous genetic improvement for both traits, but perhaps also the need to make conscious selection for Zn density along with Fe density. Lack of association of Fe and Zn densities with grain size showed that both micronutrients can be improved without compromising on seed size. The association of Fe and Zn densities with grain yield was weak and negative, but not always significant, indicating that both micronutrients can be improved without significantly compromising grain yield by using large segregating populations. This, however, is one area that merits further research.
Rai, K.N.; Yadav, O.P.; Rajpurohit, B.S.; Patil, H.T.; Govindaraj, M.; Khairwal, I.S.; Rao, A.S.; Shivade, H.; Pawar, V.Y.; Kulkarni, M.P. Breeding pearl millet cultivars for high iron density with zinc density as an associatedtrait. Journal of SAT Agricultural Research (2013) 11