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- Author or Editor: Luke S. Albert x
- Journal of the American Society for Horticultural Science x
Abstract
A method of extracting indole compounds from stem segments of woody cuttings of Ilex crenata ‘Convexa’ by refrigerated centrifugation has been developed. Effective extraction was obtained when segments were immersed in a solution of 40% ethanol (v/v) and exposed to a force of 2750 X g for at least 2 hr. Exposure to that force for more than 4 hr did not result in a significant increase in extractable auxin. Quantitative determinations of 14C measured by liquid scintillation counts of the extracts revealed that this method reliably depicted changes in levels of IAA or its metabolized forms in different stem segments as a result of different treatments. Chromatographic separation of extracts revealed that at least 35% of the label was still in the form of IAA after 48 hr. The increased levels of auxin in stem segments was also portrayed by significant rooting increases as determined by rooting index. Centrifugation extracts separated into 2 phases and were removed separately, most of the isotope was contained in the smaller lower phase. Proportionate levels of the 2 phases changed in segments over time and the lower phase disappeared at the time of rooting.
Abstract
Changes in levels of IAA in stem segments of Ilex have been detected by centrifugation extraction and subsequently identified by Rf. The radio-chemical was absorbed through intact tissue, leaf scars, wounds, or cut apical or basal ends of cuttings. It was not as readily transported to the base when it entered apical tissue through leaf scars as when it entered intact tissue of that region. When it entered basal ends of cuttings, some of it was carried to the apex within 48 hr.