Developmental and Structural Section
Die, Agathe , Kitin, Peter , Van Acker, Joris , Kouamé, François N’Guessan , Beeckman, Hans .
Cambial activity and formation of growth rings of xylem and phloem in teak (Tectona grandis) in Ivory Coast.
We investigated plantation teak that grows in conditions of one dry season from mid November to mid February and a long rainy season with two peaks, during June - July and October. Cambium was dormant or least active from November until January (monthly precipitations 30 - 50 mm). The largest cambial zone and widest layers of differentiating xylem and phloem occurred in June (400% thicker cambium relative to the dormant stage during the driest months December and January). The cambium had reduced thickness and ceased activity at the end of the rainy season in October when the monthly precipitation was still relatively high (100 mm). Reactivation started in February together with vegetative bud break at monthly precipitations below 50 mm. Cambial divisions occurred firstly at the phloem side while expanding cells were present at the xylem side. The first fully expanded vessel elements with developing secondary walls were observed in the beginning of March. A false annual ring of xylem was formed in the period February - May. In June, the current-year xylem included a fully formed layer of earlywood, wide zone of differentiating earlywood, and several cell layers of developing latewood. New phloem differentiation was initially slow and became active with the increase of the precipitation rate and development of new foliage. At least two growth rings of phloem, marked by alternating layers of sieve tubes and sclerenchyma bands, were formed in the current year. The high correlations between annual rhythm of cambial activity, phenology, and monthly precipitations show good adaptation of this imported commercial species to the local environment.
Log in to add this item to your schedule
1 - Royal Museum for Central Africa, Laboratory for Wood Biology, Leuvensesteenweg 13, Tervuren, 3080, Belgium
2 - Oregon State University, Richardson Hall 119, Corvallis, OR, 97331, USA
3 - Gent University, Faculty of Bioscience Engineering, Laboratory of Wood Technology, Ghent, 9000, Belgium
4 - Université Cocody-Abidjan, Laboratoire de Botanique, Abidjan, Ivory Coast
xylem and phloem formation.
Presentation Type: Poster:Posters for Sections
Location: Khorassan Ballroom/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 5:30 PM