Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Master → Algérie → Magister → 2014 → Biologie des chênes Algériens

Université Constantine 1 (2014)

Biologie des chênes Algériens

Medjmadj, Abla

Titre : Biologie des chênes Algériens

Auteur : Medjmadj, Abla

Université de soutenance : Université Constantine 1 (ex Mentouri)

Grade : Magister 2014

Résumé
Various representatives of the genus Quercus play a more or less important role in the formation of Algerian forests. The current status of these populations in Algeria, the regression of its range, its ecological importance and necessity in the current global context, to promote biodiversity conservation and sustainable development of ecosystems are all elements that encouraged us to study the biology of oaks in Algeria. Growth and development of oak obey to rhythmicity characterized by repeated waves of "flush" growth which vary in length from 1 to 5 weeks, which is also reflected in a heteroblastia. Modifying the expression of rhythmic growth (spatio-temporal components) is caused by several factors such as extremes temperature (low and high), the involvement of growth regulators (gibberellin, cytokinin), removing young leaves, continuous light and darkness. Histological study of the oak buds shows that all units of the next leaf stage are preformed in the bud, continuous organogenesis (part of the leaf sets of the wave of growth n is formed during the resting phase of the wave n-1 and the other during the elongation phase of the wave n) and assimilates synthesized by the leaves of the wave of growth n, are used in the construction of the wave n + 1.

Mots clés : Biologie Chênes Croissance rythmique Biology Oaks rhythmic growth

Présentation

Version intégrale

Page publiée le 17 février 2015, mise à jour le 27 septembre 2018