Variaciones en el tamano y la composicion de las yemas de Nothofagus pumilio y N. dombeyi (Fagaceae)

The length and diameter of buds were studied for #Nothofagus pumilio# and #N. dombeyi# (Fagaceae) in shoots from different types of axes of young trees growing in natural conditions. Variations in bud length according to bud position on the shoot and on the tree were assessed. In both species, shoots with more than 20 nodes developed buds with wide ranges of length and number of nodes, whereas smaller shoots always developed small buds consisting of a low number of nodes. In shoots with more than 20 nodes, bud length was maximum in buds close to the shoot's distal end. Buds of #N. pumilio# were almost twice longer and wider than those of #N. dombeyi# for each shoot size category considered. The number of nodes for buds of a given length was higher for# N. dombeyi# than #N. pumilio#. Multiple linear regressions including bud length, bud diameter, bud position on its parent shoot, and number of nodes of the parent shoot as independent variables, explained 81% and 74% of the variation in the number of leaf primordia per bud for #N. pumilio# and #N. dombeyi# respectively. (Résumé d'auteur