Periods of organogenesis in mono- and bicyclic annual shoots of Juglans regia L. (Juglandaceae).

Ann Bot

Unité Mixte de Recherche, CIRAD-CNRS-INRA-IRD-Univ. Montpellier II, Botanique et Bioinformatique de l'Architecture des Plantes, TA 40/PSII, 34398 Montpellier Cedex 5, France.

Published: August 2003

AI Article Synopsis

  • The study focused on the organogenetic cycle of shoots in 4-year-old Juglans regia trees, analyzing different types of floriferous and vegetative shoots throughout the year.
  • It monitored the development of summer growth units and examined variations in nodes, cataphylls, and embryonic leaves from mid-June to early August.
  • Findings indicate that winter buds can contain flower and leaf primordia, formed during separate growth periods, while summer growth units of bicyclic shoots develop from leaves formed in spring.

Article Abstract

The organogenetic cycle of shoots on main branches of 4-year-old Juglans regia trees was studied. Mono- and bicyclic floriferous and vegetative annual shoots were analysed. Five parent annual shoot types were sampled between October 1992 and August 1993. Organogenesis of summer growth units was monitored between 16 Jun. and 3 Aug. 1993. Variations over time in the number of nodes, cataphylls and embryonic green leaves of terminal buds were studied. The number of nodes of parent shoot buds was compared with the number of nodes of shoots derived from parent shoot buds. The spring growth units of mono- and bicyclic shoots consist exclusively of preformed leaves which were differentiated, respectively, during the spring flush of growth (mid-April until mid-May) or the summer flush of growth (mid-June until early August) in the previous growing season. Thus, winter buds may consist of flower and leaf primordia differentiated in two different periods during annual shoot extension. The summer growth units of bicyclic shoots consist of preformed leaves that were differentiated in spring buds during the spring flush of growth in the current growing season. Bud morphology is compared between spring and summer shoots.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4243650PMC
http://dx.doi.org/10.1093/aob/mcg127DOI Listing

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