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-a llelic dwarfs of pearl millet Pennisetum glaucum (L.) R. Br. One mutan t (d3), with an extreme dwarf phenotype, was found to be deficient in all GAs measured; the others (d1, d2, d4 and the quantitatively inheri ted 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 moderat e responses at the seedling stage, depending on the season, and no res ponse 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.