Response to Selection for Increased Individual Grain Mass in Pearl Millet

Although pearl millet [Pennisetum glaucum (L.) R. Br.] is traditionally a small grain crop, a trait associated with adaption to marginal environments, there are both agronomic and usage-related reasons for seeking to increase individual grain mass (or size). Individual grain mass appears to have a low to moderate heritability in pearl millet, suggesting that genetic improvement based on some form of progeny testing is likely to be effective. The objective of this research was to quantify the percentage increase in individual grain mass that could be achieved in a modern open-pollinated millet cultivar, ICMS 7703, by two cycles of recurrent S1 progeny selection for increased grain mass and maintenance of grain yield potential. Evaluated across 10 test environments, two cycles of selection achieved an 18% increase in individual grain mass (8.05–9.52 mg per grain), with no change in grain yield per square meter. Substantial improvement in individual grain mass in pearl millet is thus possible with targeted recurrent selection, where larger seed size provides an agronomic or processing advantage, or enhances consumer preference