CHANGE IN TISSUE MINERAL ELEMENTAL CONCENTRATION DURING ROOT INITIATION AND DEVELOPMENT OF POINSETTIA CUTTINGS

摘要

Variation in tissue elemental concentration in apical stem cuttings of 'Lilo' and 'V-10 Amy' poinsettia (Euphorbia pulcherrima Willd. ex. Klotzch) were studied during the initiation and development of adventitious roots. Changes in selected macro- and microelement concentrations coincided with root initiation (i.e., Pe, Cu, and Mo accumulated in the basal portions of stem cuttings during early root initiation before root primordia elongation); P, K, Ca, and Mg concentrations declined. During root primordia elongation and root emergence, Fe, Cu, and Mo and Mg, Mn, B, and Zn concentrations continued to increase at the cutting bases, but P and K concentrations remained low compared to when cuttings were initially inserted in the propagation medium. When all cutting of both cultivars had rooted, foliar N, Fe, and Mo concentrations declined, but Cu increased compared to when cuttings were initially propagated.