High genetic diversity and clonal growth in relict populations of Olea europaea subsp. laperrinei (Oleaceae) from Hoggar, Algeria.

Détails

Ressource 1Télécharger: BIB_298DD11299F6.P001.pdf (164.28 [Ko])
Etat: Serval
Version: Final published version
ID Serval
serval:BIB_298DD11299F6
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
High genetic diversity and clonal growth in relict populations of Olea europaea subsp. laperrinei (Oleaceae) from Hoggar, Algeria.
Périodique
Annals of botany
Auteur(s)
Baali-Cherif D., Besnard G.
ISSN
0305-7364 (Print)
ISSN-L
0305-7364
Statut éditorial
Publié
Date de publication
10/2005
Peer-reviewed
Oui
Volume
96
Numéro
5
Pages
823-830
Langue
anglais
Notes
Publication types: Journal Article
Publication Status: ppublish
licence nationnale
Résumé
The Laperrine's olive (Olea europaea subsp. laperrinei) is an endemic tree from Saharan massifs. Its populations have substantially regressed since the Pleistocene and are presently distributed in a fragmented habitat. Long-term persistence of this taxon is uncertain and programmes of preservation have to be urgently implemented. To define a conservation strategy, the genetic diversity and breeding system of this tree have to be investigated.
One hundred and eleven ramets were prospected in the laperrinei populations from the Tamanrasset region, southern Algeria. Genetic polymorphism was revealed at nuclear and chloroplast DNA (cpDNA) microsatellite loci allowing a comparative assessment of the genetic diversity of laperrinei and Mediterranean populations based on bi-parental and maternal markers. Additionally, nuclear microsatellite markers enabled the genotypes to be identified unambiguously.
Based on nuclear microsatellite data, the total diversity was high (Ht=0.61) in laperrinei populations and similar to that observed in western Mediterranean populations. A substantial cpDNA diversity (Ht=0.19) was also observed. Genetically identical ramets originated from the same stump (which can cover >80 m2) were identified in each population. Sixteen per cent of genets exhibited more than one ramet. In addition, several cases of somatic mutations were unambiguously revealed in distinct ramets stemming from the same stump.
These data show that highly isolated and small laperrinei populations are able to maintain a high genetic diversity. This supports the existence of relict trees persisting for a very long time (probably since the last humid transition, 3000 years ago). It is proposed that the very long persistence associated with an asexual multiplication of highly adapted trees could be a strategy of survival in extreme conditions avoiding a mutational meltdown due to reproduction in reduced populations.
Mots-clé
Algeria, Biological Evolution, DNA, Plant/genetics, Genetic Variation, Microsatellite Repeats/genetics, Olea/genetics, Olea/growth & development, Phylogeny, Polymorphism, Genetic/genetics, Reproduction
Pubmed
Web of science
Création de la notice
20/01/2008 16:16
Dernière modification de la notice
13/07/2018 10:18
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