Terminal drought and a d dwarfing gene affecting grain iron and zinc density in pearl millet

Abstract

a b s t r a c tPearl millet, predominantly a rainfed dryland crop, often encounters terminal drought in crop season. Grain hybrids grown in India are of medium to tall height, and majority of them are based on d 2 dwarf seed-parents. Eight pairs of tall and d 2 dwarf isogenic-lines, developed from two diverse composites, were evaluated under irrigated control and imposed terminal drought for two-years to examine the effect of d 2 dwarfing gene and terminal drought on grain iron (Fe) and zinc (Zn) density. In general, terminal drought had a significant effect on increasing the Fe and Zn density, the d 2 dwarfing gene or the linked gene block significantly decreased both micronutrients, with the magnitude of increase or decrease, respectively, dependent on the environment and genetic background of the isolines. Terminal drought has severe adverse impact on grain yield, but grains produced from such environments are likely to be more nutritious with respect to Fe and Zn density. The d 2 dwarf hybrids are likely to be less nutritious than non-d 2 hybrids with respect to Fe and Zn density. Whether the d 2 dwarf seed parents with reduced Fe and Zn density presumably may adversely affect grain yield and micronutrient levels of even non-d 2 hybrids developed on them, and this aspect merits further investigation.

Identification of High-Yielding Iron-Biofortified Open-Pollinated Varieties of Pearl Millet in West Africa

“…The ASV has identified the genotype CHAKTI as the most prominent genotype that outperformed across the majority of the locations, indicating this as a stable performing genotype across environments. The ASV parameter has been successfully used in several studies to find stable performers ( Mallikarjuna et al, 2015 ; Govindaraj et al, 2018 ). CHAKTI is the top-ranking OPV that had a lower ASV of 0.5–2.0 for grain yield and micronutrients, and still, it ranked first in 6 out of 10 locations and second in only 1 location.…”

“…The HarvestPlus program of the CGIAR is supporting global biofortification efforts, through which the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) released the ever-first high grain Fe pearl millet variety "Dhanashakti" in 2014 by exploiting the intrapopulation variability (recurrent selection) within ICTP 8203 variety, an early open-pollinated variety (OPV) popularly grown in India (Rai et al, 1990;Govindaraj et al, 2019). Since then, pearl millet hybrids rich in kernel iron and zinc concentrations have been bred and released in India through conventional (i.e., heterosis) breeding methods (Govindaraj et al, 2018(Govindaraj et al, , 2019.…”