Distribution of genetic diversity in Pinus pinaster Ait. as revealed by chloroplast microsatellites |
| |
Authors: | G G Vendramin M Anzidei A Madaghiele G Bucci |
| |
Institution: | (1) Istituto Miglioramento Genetico Piante Forestali, Consiglio Nazionale delle Ricerche, Via Atto Vannucci 13, 50134 Firenze, Italy Fax: +39 55 486604 E-mail: vendramin@imgpf.fi.cnr.it, IT |
| |
Abstract: | Using nine chloroplast simple sequence.repeats (cpSSRs) markers, we evaluated haplotypic variation within and among natural
populations of Maritime pine (Pinus pinaster Ait.) in order to shed light on the history of this species. Seven out of the nine cpSSRs analysed were polymorphic, giving
a total of 24 different variants. The 24 variants combined in 34 different haplotypes. The populations which generally showed
the lowest level of haplotypic diversity are those located in Portugal. The Landes (France) and Pantelleria (Italy) populations
represent the two main reservoirs of haplotypic diversity. The proportion of genetic differentiation among populations, estimated
using Rst, which is a measure based upon a strict stepwise mutation model, was 0.235. The high level of differentiation was also confirmed
by the AMOVA analysis (ΦST=0.254, P<0.001). Four main groups of populations were identified on the basis of Principal Component Analysis, with the differences
being statistically significant (ΦCT=0.299, P<0.001). Based on our results the presence of refugia located in the South of Portugal, previously proposed for this species,
may be excluded, and a different possible recolonization process of Maritime pine in the post-glacial period has been proposed.
Populations from North Africa and France might have represented a starting point of the recolonization process of Portugal
and of the Italian part of the natural range, respectively. This hypothesis seems to be confirmed by the analysis of the distribution
of the pairwise differences among individuals within populations: Landes and Pantelleria populations showed a bimodal distribution,
as would be expected for ancient gene pools.
Received: 5 November 1997 / Accepted: 5 January 1998 |
| |
Keywords: | cpSSR Haplotypic diversity Recolonization pathway Evolutionary history |
本文献已被 SpringerLink 等数据库收录! |
|