Dwarfing Gene Effects on Coleoptile Length in Pearl Millet

Dwarfing genes have been reported to affect either or both the length of the coleoptile and mesocotyl in several cereal species, which can reduce seedling emergence. Such an effect of dwarfing genes has not been reported for pearl millet [Pennisetum glaucum (L.) R. Br.]. The objective of this study was to assess the effect of the d2 dwarfing gene in pearl millet on the length of the coleoptile, mesocotyl, and plumule in 12 pairs of isogenic tall/dwarf (d2) inbred lines and pairs of isogenic tall/dwarf hybrids. Calm lengths were measured in replicated field trials in two seasons and the lengths of coleoptiles and mesocotyls in seedlings germinated in incubators in the dark at 35 °C. Culm length differed significantly between tall and dwarf entries of both inbreds and hybrids but the length of both coleoptile and mesocotyi were similar in both height classes. There were significant differences in coleoptile and mesocotyl lengths among individual entries tested but these were due to parental line or hybrid parent effects. The d2 gene in pearl millet did not affect coleoptlle or mesocotyl length as reported for dwarfing genes in other cereals.