1. The role of nodal regions in growth of Xanthium (Compositae) stem
- Author
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Maksymowych, Roman and Orkwiszewski, Joseph A.J.
- Subjects
Compositae -- Physiological aspects ,Stems (Botany) -- Research ,Biological sciences - Abstract
Vegetative Xanthium plants grown under noninductive conditions were marked with India ink along the stem and photographed at three consecutive time intervals. Relative elemental rates (d(dX/dt)/dX) of stem elongation were estimated from displacement of marks during stem elongation. Young internodes elongated with constant relative elemental rates of 0.2 day to the -1. Older internodes displayed an acropetal pattern of elongation in which the basal segments of an internode stopped elongating first and the apical portion last. Nodal regions elongated with very small relative elemental rates of 0.05 day to the -1. Rates decreased as the age of the internodes and nodes increased and stopped shortly after Leaf Plastochron Index 9.
- Published
- 1993