Preformation and neoformation in shoots of Nothofagus antarctica (G. Forster) Oerst. (Nothofagaceae) shrubs from Northern Patagonia

Puntieri Javier G., Stecconi Marina, Barthélémy Daniel. 2002. Preformation and neoformation in shoots of Nothofagus antarctica (G. Forster) Oerst. (Nothofagaceae) shrubs from Northern Patagonia. Annals of Botany, 89 : 665-673.

Autre titre : Préformation et néoformation chez les tiges d'arbustes de Nothofagus antarctica (G. Forster) Oerst. (Nothofagaceae) du nord de la Patagonie

Résumé : The size (length and diameter) and number of leaf primordia of winter buds of #Nothofagus antarctica# (G. Forster) Oerst. shrubs were compared with the size and number of leaves of shoots derived from buds in equivalent positions. Buds developed in two successive years were compared in terms of size and number of leaf primordia. Bud size and the number of leaf primordia per bud were greater for distal than for proximally positioned buds. Shoots that developed in the five positions closest to the distal end of their parent shoots had significantly more leaves than more proximally positioned shoots of the same parent shoots. The positive relationship between the size of a shoot and that of its parent shoot was stronger for proximal than for distal positions on the parent shoots. For each bud position on the parent shoots there were differences in the number of leaf primordia per bud between consecutive years. The correlations between the number of leaf primordia per bud and bud size, bud position and parent shoot size varied between years. Only shoots produced close to the distal end of a parent shoot developed neoformed leaves; more proximal sibling shoots consisted entirely of preformed leaves. Leaf neoformation, a process usually linked with high shoot vigour in woody plants, seems to be widespread among the relatively small shoots developed in #N. antarctica# shrubs, which may relate to the species' opportunistic response to disturbance.

Mots-clés Agrovoc : Nothofagus, tige, organogénèse, croissance, pousse, ramification, feuille

Mots-clés géographiques Agrovoc : Argentine

Mots-clés complémentaires : Nothofagus antarctica

Classification Agris : F50 - Anatomie et morphologie des plantes
F62 - Physiologie végétale - Croissance et développement

Auteurs et affiliations

• Puntieri Javier G., Universidad Nacional del Comahue (ARG)
• Stecconi Marina, Universidad Nacional del Comahue (ARG)
• Barthélémy Daniel, CIRAD-AMIS-AMAP (FRA) ORCID: 0000-0003-3187-2517

Source : Cirad - Agritrop (https://agritrop.cirad.fr/490804/)

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