03048naa a2200397 a 450000100080000000500110000800800410001910000170006024501620007726000090023952018960024865000150214465000220215965000210218165000190220265000140222165000130223565000150224865000280226365000190229165000110231065000220232165000210234365000210236465000200238565000240240565000220242965000290245165300140248065300180249465300130251265300190252570000170254470000180256177300710257913674491998-04-06       1995    bl ---       0--  u    #d1 aJONES, L. H.  aAn evaluation of the role of cytokinins in the development of abnormal inflorescences in oil palms (Elaeis guineensis Jacq.) regenerated from tissue culture.  c1995  aTissue cultures and regenerant plants from cell lines producing palms with normal and abnormal flowers were analysed for cytokinin content and compared with zygotic embryos and seedlings. Immature inflorescences at the critical stage of flower development dissected from normal and abnormal palms were also analysed. HPLC/radioimmunoassay and HPLC/enzyme-linked immunosorbent assay methods were used over a period of several years to measure the isoprenoid cytokinins. Oil palm cultures and regenerant plants contained relatively high concentrations of the 9-glucosides of isopentenyladenine ([9G]ip) and zeatin ([9g]Z). The predominant biologically active isoprenoid cytokinin present was zeatin riboside ([9R]Z), with lesser amounts of isopentenyladenine (iP) and isopentenyladenosine ([9R]iP). There was evidence of small amounts of dihydrozeatin compounds, but high concentrations (mainly as dihydrozeatin-9-glucoside ([9G]DHZ)) were confined to the haustorium of the zygotic embryo. Callus tissue contained very low concentrations of cytokinin. Comparison of 2 isogenic lines of one clone giving rise to normal and abnormal palms showed significantly higher concentrations of [9R]Z and [9G]Z in the normal than in the abnormal line and, in embryoids only, higher [9G]iP in the normal line. In all other cases the between-clone differences were greater than any normal/abnormal differences. There was a general tendency for increased concentrations of [9G]iP in abnormal lines and for this compound to be in a higher concentration in embryoids and plants derived from culture than in zygotic embryos and seedlings. Analysis of cytokinins in immature female inflorescences of normal and abnormal palms of a single clone showed the abnormal inflorescences to have higher concentrations of [9R]Z and [9R]DHZ and less [9G]Z than the normal inflorescences at comparable stages of development.  acytokinins  agrowth regulators  ain vitro culture  ainflorescences  aoil crops  aoilseeds  aphysiology  aplant growth substances  atissue culture  azeatin  aCultura de Tecido  aCultura In Vitro  aEmbrião Vegetal  aInflorescência  aPalmeira Oleaginosa  aPlanta Oleaginosa  aRegulador de Crescimento  aOil palms  aPlant embryos  aSementes  aTropical crops1 aHANKE, D. E.1 aEEWENS, C. J.  tJournal of Plant Growth Regulationgv. 14, n. 3, p. 135-142, 1995.