COLEOPTILE LENGTH, GIBBERELLIN SENSITIVITY AND CONCENTRATIONS IN 5 NON-ALLELIC DWARF MUTANTS OF PEARL-MILLET - PENNISETUM-GLAUCUM (L) R BR

The concentrations of endogenous gibberellins (GAs) were determined by combined gas chromatography-mass spectrometry in shoots of five non-allelic dwarfs of pearl millet Pennisetum glaucum (L.) R. Br. One mutant (d3), with an extreme dwarf phenotype, was found to be deficient in all GAs measured; the others (d1, d2, d4 and the quantitatively inherited dwarf) had similar levels of GAs to the tall genotype. Only the GA-deficient dwarf recovered the tall phenotype in response to applying GA(3) up to the adult stage, while the others showed slight to moderate responses at the seedling stage, depending on the season, and no response at later stages. The dl, d3 and d4 dwarfs had short coleoptiles. A wide range of coleoptile lengths with a normal distribution pattern was observed in the tall, d2 and the quantitatively inherited dwarf, suggesting that there is polygenic control of this trait.