gene flow; Erythrophleum suaveolens; kinship and paternity analyses; direct methods; indirect methods; seeds and pollen dispersal; Flux de gènes; analyses de parenté, paternité; méthodes directes; méthodes indirectes; dispersion des graines et du pollen
Abstract :
[en] The study of the regeneration of tropical timber species is intended to design appropriate conservation strategies and to enable the sustainable exploitation of their populations. This study based on sample collection made in Cameroon and Gabon in two forest contexts with different population densities, has allowed us to characterize gene flow from tali (Erythrophleum suaveolens) using molecular markers. Direct methods based on analyzes of kinship and proceeding by maximum likelihood, as well as indirect methods based on the heterogeneity of the pollen pool and on the spatial structure of the population, allowed the reconstruction of the events of seed and pollen dispersal. The results show that the species present an exponential distribution of pollen and seeds, the average distance of pollen dispersal would be 240 meters and that of seeds would be 135 meters. We also defined a minimum effective density of 0.09 to 0.2 individuals per hectare depending on the forest context studied. The tali has a rate of inbreeding of 25% to 30 % coupled with strong inbreeding depression. These two features are most likely to affect the regeneration of the species in case of overexploitation. [fr] L’étude de la régénération des essences commerciales tropicales a pour but la proposition de stratégies utiles à leur aménagement afin de permettre l’exploitation durable de leurs populations. Cette étude a permis, à partir de la collecte d’échantillons opérée au Cameroun et au Gabon dans deux contextes forestiers présentant des densités de population différentes, de caractériser les distances de flux de gènes du tali (Erythrophleum suaveolens) à l’aide de marqueurs moléculaires. Des méthodes directes basées sur des analyses de parenté et procédant par maximum de vraisemblance, ainsi que des méthodes indirectes basées sur l’hétérogénéité du pool pollinique ainsi que sur la structure spatiale de la population, ont permis de reconstruire les événements de dispersion des graines et du pollen. Cette essence présenterait une distribution exponentielle de dispersion du pollen et des graines, la distance moyenne de dispersion du pollen serait de 240 mètres et celle des graines serait de 135 mètres. Nous avons aussi défini une densité effective minimale de 0,09 à 0,2 individus par hectare en fonction du contexte forestier étudié. Le tali présenterait un taux d’autofécondation de 25% à 30 % couplé à une forte dépression de consanguinité. Ces deux caractéristiques sont les plus susceptibles d’affecter la régénération de l’essence en cas d’exploitation trop intensive de la ressource.
This website uses cookies to improve user experience. Read more
Save & Close
Accept all
Decline all
Show detailsHide details
Cookie declaration
About cookies
Strictly necessary
Performance
Strictly necessary cookies allow core website functionality such as user login and account management. The website cannot be used properly without strictly necessary cookies.
This cookie is used by Cookie-Script.com service to remember visitor cookie consent preferences. It is necessary for Cookie-Script.com cookie banner to work properly.
Performance cookies are used to see how visitors use the website, eg. analytics cookies. Those cookies cannot be used to directly identify a certain visitor.
Used to store the attribution information, the referrer initially used to visit the website
Cookies are small text files that are placed on your computer by websites that you visit. Websites use cookies to help users navigate efficiently and perform certain functions. Cookies that are required for the website to operate properly are allowed to be set without your permission. All other cookies need to be approved before they can be set in the browser.
You can change your consent to cookie usage at any time on our Privacy Policy page.