biologia plantarum

Biologia plantarum 48:381-388, 2004 | DOI: 10.1023/B:BIOP.0000041090.36790.86

Senescence of Unfertilised Flowers in Epiphyllum Hybrids

O. Erdelská¹, M. Ovečka²

¹ Institute of Botany, Slovak Academy of Sciences, Bratislava, Slovak Republic

² Institute of Ecology and Conservation Biology, University of Vienna, Vienna, Austria, e-mail

Epiphyllum hybrids served as a model for the study of reserve remobilisation from unfertilised flowers to the mother stem tissues. Early phases of the tube senescence characterised by wilting were connected with degradation and transfer of reserve substances to the somatic organs of the mother plant. The degradation process began in perianth and stamens and continued through the successive zones (receptacular, pericarpellar and pedicellar) of the flower tube. The phloem-mediated backward substance transport was naturally indicated by the red pigment of the perianth -- cactorubin, while integrity of cells and tissues and green colour of the flower tube were still preserved. For the later phases of senescence the loss of permeability and successive breaking of the cell integrity, connected with the colour change of the tube from green to red was evident. The functioning of vascular bundles especially their phloem parts conducting dissolved substances to the sinks in mother stem organs were preserved until late stages of senescence. The recycling and remobilisation of nutrients from all parts of unfertilised ovary and ovules may be considered as a part of the life strategy in the family Cactaceae as well as in other taxa evolutionarily adapted to life in extreme environmental conditions.

Keywords: cactorubin; perianth; substance remobilisation

Subjects: cactorubin; cell death, programmed; Epiphylum hybrids; epiphytic cacti, hybrids; flower, senescence; perianth, senescence of unfertilized flowers; programmed cell death; reserve remobilisation, model to study; substance remobilisation from unfertilised flowers

Published: September 1, 2004  Show citation