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1.
M. M. Ribeiro C. Plomion R. Petit G. G. Vendramin A. E. Szmidt 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(1):97-103
Genetic variation in 12 Pinus pinaster (maritime pine) populations spanning most of the distribution range of the species in Portugal was evaluated using six polymorphic
chloroplast microsatellite (cpSSR) loci. Thirty-two haplotypes were found. There were indications of very weak differentiation
among populations (Weir’s θcoefficient, 0.023), and the R
ST value, derived from the stepwise mutation model (SMM), was not significantly different from zero. The pattern, in which similarities
in allele size, in base pairs, do not contribute to the genetic structure, may be due to the recent mixing of genetic material
from different stands through plantations. Overall, a high level of haplotypic variation within populations was detected.
Using the SMM estimator (mean genetic distance of individuals within populations, D
2
sh
–––) we divided the populations into two groups, with above and below average values. The first group contained 5 populations,
mainly from the central part of the country, which possess, in general, high levels of haplotypic diversity. Among them, 2
populations were divergent from the others based on the pair-wise Nei’s distance. The results indicate that there is no discernible
geographic genetic pattern for the Portuguese populations of P. pinaster investigated. The history of expansion of the species range in Portugal during the twentieth century (mainly due to human
activity) and extensive gene flow among populations associated with the expansion could explain this finding.
Received: 15 February 2000 / Accepted: 14 April 2000 相似文献
2.
This paper illustrates the phylogeographical structure of Saxifraga callosa in order to describe its genetic richness in refugial areas and to reconstruct its glacial history. S. callosa is a species spread throughout south-east France and Italy with a high distribution in the Maritime Alps. Four chloroplast
microsatellite and AFLP markers were analyzed in populations of S. callosa. The size variants of all tested loci amount to 11 different haplotypes. Intrapopulational haplotype variation was found
in two of the populations analyzed: on the Mt. Toraggio in the Maritime Alps, and in the Apuan Alps. On the other hand, no
intrapopulational variation was found in 25 populations, most of which were sampled from isolated areas. Analysis of the haplotype
distribution showed that population subdivision across all populations was high (G
ST = 0.899). Moreover, its genetic structure was studied using AMOVA and STRUCTURE analysis. The study legitimated inferred
conclusions about the phylogeographical structure of the species and identified centers of diversity. Considerations concerning
genetic structure and divergence among three major clades (Maritime Alps, Apuan Alps and Apennines), the patchy distribution
of haplotypes, and the high number of private haplotypes support the proposal that S. callosa survived in some refugia within the Italian Peninsula refugium, and that mainly northern populations of refugia were involved
in postglacial recolonization. 相似文献
3.
Maria Höhn Felix Gugerli Peter Abran György Bisztray Anna Buonamici Klara Cseke Levente Hufnagel Celestino Quintela-Sabarís Federico Sebastiani Giovanni Giuseppe Vendramin 《Journal of Biogeography》2009,36(9):1798-1806
Aim To characterize the genetic structure and diversity of Pinus cembra L. populations native to two disjunct geographical areas, the Alps and the Carpathians, and to evaluate the rate of genetic differentiation among populations. Location The Swiss Alps and the Carpathians. Methods We screened 28 populations at three paternally inherited chloroplast simple sequence repeats (cpSSRs) for length variation in their mononucleotide repeats. Statistical analysis assessed haplotypic variation and fixation indices. Hierarchical analysis of molecular variance (AMOVA), Mantel test, spatial analysis of molecular variance (SAMOVA) and barrier analyses were applied to evaluate the geographical partitioning of genetic diversity across the species’ range. Results Haplotypic diversity was generally high throughout the natural range of P. cembra, with the mean value substantially higher in the Carpathians (H = 0.53) than in the Alps (H = 0.35). The isolated Carpathian populations showed the highest haplotype diversity among the populations originating from the High Tatras (Velka Studena Dolina) and South Carpathians (Retezat Mountains). AMOVA revealed that only 3% of the total genetic variation derived from genetic differentiation between the two mountain ranges. Differentiation among Carpathian populations was higher (FST = 0.19) than among Alpine populations (FST = 0.04). Low, but significant, correlation was found between the geographical and genetic distances among pairs of populations (r = 0.286, P < 0.001). SAMOVA results revealed no evident geographical structure of populations. barrier analysis showed the strongest differentiation in the eastern part of the species’ range, i.e. in the Carpathians. Main conclusions The populations of P. cembra within the two parts of the species’ range still share many cpDNA haplotypes, suggesting a common gene pool conserved from a previously large, continuous distribution range. Carpathian populations have maintained high haplotypic variation, even higher than Alpine populations, despite their small population sizes and spatial isolation. Based on our results, we emphasize the importance of the Carpathian populations of Swiss stone pine for conservation. These populations comprise private haplotypes and they may represent a particular legacy of the species’ evolutionary history. 相似文献
4.
S.-Y. Lu K.-H. Hong S.-L. Liu Y.-P. Cheng W.-L. Wu T.-Y. Chiang 《Journal of plant research》2002,115(3):0203-0216
We used sequence variation of the atpB-rbcL intergenic spacer of cpDNA and nested clade analysis to assess the phylogeographic pattern of Michelia formosana, a species restricted to Taiwan and the Ryukyus. In total, 31 haplotypes were identified and clustered into four major chlorotypes.
Genetic composition of nearly all populations was heterogeneous and paraphyletic phylogenetically. Although the apportionment
of cpDNA variation hardly revealed a geographic pattern due to the coancestry of dominant sequences, some chlorotypes were
restrictedly distributed. According to the patterns of clade dispersion and displacement, a reconstructed minimum spanning
network revealed that historical events of past fragmentation and range expansion, associated with glaciation, may have shaped
the phylogeographic patterns of M. formosana. Four possible refugia were identified: the Iriomote and Ishigaki Islands (the southern Ryukyus), Wulai (northern Taiwan),
and Nanjen (southern Taiwan), on the basis of the interior positions of their haplotypes in the network and the high level
of nucleotide diversity. Given insufficient time for coalescence at the cpDNA locus since the late Pleistocene recolonization,
lineage sorting led to low levels of genetic differentiation among populations. In contrast, hierarchical examination of the
random amplified polymorphic DNA (RAPD) data scored from six populations across three geographical regions, using an analysis
of molecular variance (AMOVA), indicated high genetic differentiation both among populations (ΦST = 0.471) and among regions (ΦCT = 0.368). An unweighted pair group method with arithmetic mean (UPGMA) tree of the RAPD fingerprints revealed that populations
of two offshore islands of eastern Taiwan (M. formosana var. kotoensis) were clustered with geographically remote populations of the Ryukyus instead of those in southern Taiwan, suggesting some
historical division due to geographic barriers of the central mountain range. In contrast to the paraphyly of the nearly neutral
cpDNA alleles, differentiated RAPDs may have experienced diversifying selection.
Received: July 2, 2001 / Accepted: February 20, 2002 相似文献
5.
Teresa Vasconcelos Agnès Horn François Lieutier Manuela Branco† Carole Kerdelhué‡ 《Agricultural and Forest Entomology》2006,8(2):103-111
1 The Mediterranean pine shoot beetle Tomicus destruens has long been indistinguishable from its congeneric Tomicus piniperda. Both species attack pines, and can be found in sympatry. The geographical distribution of T. destruens is still unclear in most of the Mediterranean Basin. 2 We aimed to describe the geographical distribution and zones of sympatry of both species in the Iberian Peninsula and France, and to study the molecular phylogeographical pattern of T. destruens. 3 Tomicus spp. adults were sampled in Portugal, Spain and France, and a portion of the mitochondrial genes COI and COII was sequenced for 84 individuals. Sequences were aligned to a data set previously obtained from French localities. 4 Tomicus destruens was found in all populations, except for one locality in Portugal and in the Landes (France). It was in sympatry with T. piniperda in two locations on Pinus pinaster and one location on Pinus radiata. 5 Within‐population genetic diversity was high, but we found a significant pattern of spatial distribution of genetic variation, as well as a significant effect of the host tree. 6 The data suggest the existence of two glacial refugia, from which T. destruens recolonized its current range. One refugium was located in Portugal where the beetle probably evolved on P. pinaster. The corresponding haplotypes show a West–East frequency gradient. The other refugium was probably in the eastern range, where the beetles evolved on Pinus halepensis and P. pinea. The corresponding haplotypes show an East–West frequency gradient. 相似文献
6.
Berchemiella wilsonii var. pubipetiolata (Rhamnaceae) is an endangered tree in eastern China. Habitat destruction has resulted in fragmentation of remnant populations
and extinction of local populations. AFLP and cpDNA markers were used to determine the population structure of remnant populations
of B. wilsonii var. pubipetiolata. Moderate nuclear genomic diversity was found within each of the four remnant populations (H
S = 0.141–0.172), while the cpDNA haplotype diversity in each population ranged from 0.356 to 0.681. Six haplotypes were identified
by a combined cpRFLP and cpSSR analysis in a total of 89 individuals. AMOVA revealed significantly AFLP genetic differentiation
within and between regions (ΦSC = 0.196, ΦCT = 0.396, respectively), and a high cpDNA haplotype differentiation between regions (ΦCT = 0.849). The results suggest low gene flow between populations of B. wilsonii var. pubipetiolata. Strong genetic divergence between two regional populations as revealed by both AFLP and cpDNA markers provided convincing
evidence that two distinct evolutionary lineages existed, and should be recognized as ‘evolutionary significant units’ (ESUs)
for conservation concerns. 相似文献
7.
Shin-Ichi Seki Hajime Takano Kazuto Kawakami Nobuhiko Kotaka Akira Endo Kenji Takehara 《Conservation Genetics》2007,8(5):1109-1121
The Japanese wood pigeon (Columba janthina) is endemic to the islands of East Asia and it is included in the Japanese and Asian Red Lists because of its narrow habitat
range that is restricted to mature forests on small islands and because of the destruction of these habitats. We examined
the genetic structure of Columba janthina by studying 463 base pairs of the mitochondrial control region sequences. We analyzed 154 samples from eight populations
and identified 27 haplotypes. Three population groups were identified based on the pairwise ΦST values. A substantial gene flow, as reflected by the low and non-significant ΦST values, is maintained among the northern group that includes six populations found on the Okinawa, Tokara, Goto, Setouchi,
Oki, and Izu islands. In contrast, the southeastern group found on the Ogasawara Islands had large ΦST values with every population from other regions (0.910 < ΦST < 0.962). The southwestern group found on the Sakishima Islands also had significant but small ΦST values with every population from the northern group (0.081 < ΦST < 0.205). The Mantel test showed a highly significant correlation between the ΦST values and the route length of the habitat network, as well as the linear distance with correction of the habitat gap effect,
indicating the importance of the closely connected structure of the habitats. The three groups mentioned above could be considered
as independent management units, and the southeastern group has the highest conservation priority due to its narrow distribution
range and small population size.
Electronic Supplementary Material The online version of this article (doi: ) contains supplementary material, which is available to authorized users. 相似文献
8.
Genetic structure of montane isolates of Pinus sylvestris L. in a Mediterranean refugial area 总被引:2,自引:2,他引:0
Aim This work investigates the population genetic effects of periodic altitudinal migrations and interstadial fragmentation episodes in long‐term Scots pine (Pinus sylvestris L.) populations at a regional scale. Location The study focuses on Scots pine populations in the northern Meseta and peripheral mountain chains, central and north‐western Iberian Peninsula. The ample macrofossil record in the area shows that this 60,000‐km2 region represent a glacial refugium for Scots pine. The species occupied large areas on the Meseta plains during glacial cold stages, but it has periodically sheltered at high elevation in the surrounding mountain chains during warm episodes, conforming to a fragmented pattern similar to its present‐day distribution. Methods We perform a fine‐scale chloroplast microsatellite (cpSSR) survey to assess the genetic structure of 13 montane Scots pine isolates in the northern Meseta (total N = 322 individuals). Using a hierarchical analysis of molecular variance (amova ), we test the hypothesis of genetic isolation among disjunct mountain areas. We use a standard coalescence model to estimate genealogical relationship among populations, investigating the potential role of the regional relief as a factor influencing historic gene exchange among Scots pine populations. Results Population haplotypic diversity was high among Scots pine populations (He = 0.978), greater than values reported for other more thermophilic pine species in the Iberian Peninsula. The amova revealed low (but significant) differentiation among populations (ΦST = 0.031, P = 0.010), showed that the disjoint montane distribution could not account for the genetic divergence among areas (ΦCT = 0.012, P = 0.253), and that there was non‐trivial subdivision among populations within the same mountain region (ΦSC = 0.021, P = 0.012). The genealogical relationships among populations showed that Scots pine isolates growing on disjoint mountain blocks, but on slopes flowing to the same basin, were genetically closer than populations growing on different slopes of the same mountain chain, flowing to different basins. Main conclusions The observed genetic structure for Scots pine is consistent with its population history, inferred from the palaeobotanical record, with vertical migrations throughout climatic pulses and with the drainage basins and large long‐term population sizes connecting different mountain blocks during the cooler glacial periods. Overall, the results suggest that, despite periodic interstadial fragmentation episodes, Scots pine biology provides for the long‐term maintenance of high within‐population and low among‐population genetic diversity at neutral genetic markers. 相似文献
9.
Identifying factors that cause genetic differentiation in plant populations and the spatial scale at which genetic structuring can be detected will help to understand plant population dynamics and identify conservation units. In this study, we determined the genetic structure and diversity of Pterocarpus officinalis, a widespread tropical wetland tree, at three spatial scales: (1) drainage basin “watershed” (<10 km), (2) within Puerto Rico (<100 km), and (3) Caribbean-wide (>1000 km) using AFLP. At all three spatial scales, most of the genetic variation occurred within populations, but as the spatial scale increased from the watershed to the Caribbean region, there was an increase in the among population variation (ΦST=0.19 to ΦST=0.53). At the watershed scale, there was no significant differentiation (P=0.77) among populations in the different watersheds, although there was some evidence that montane and coastal populations differed (P<0.01). At the island scale, there was significant differentiation (P<0.001) among four populations in Puerto Rico. At the regional scale (>1000 km), we found significant differentiation (P<0.001) between island and continental populations in the Caribbean region, which we attributed to factors associated with the colonization history of P. officinalis in the Neotropics. Given that genetic structure can occur from local to regional spatial scales, it is critical that conservation recommendations be based on genetic information collected at the appropriate spatial scale. 相似文献
10.
Jorge C. Pereira Raquel Chaves Alexandra Leitão Domitilia Matias Henrique Guedes-Pinto 《Helgoland Marine Research》2011,65(3):361-367
The clam Ruditapes decussatus is commercially important in the south of Portugal. The random amplified polymorphic DNA (RAPD) technique was applied to
assess the genetic diversity and population structure of two Portuguese populations occurring in the Ria Formosa (Faro) and
the Ria de Alvor, respectively. Twenty-five individuals of each population were investigated by RAPD profiles. Genetic diversity
within populations, measured by the percentage of polymorphic loci (%P), varied between 68.57% (Alvor) and 73.88% (Faro). Shannon’s information index (H) and Nei’s gene diversity (h) were 0.281 and 0.176, respectively, for the Alvor population and 0.356 and 0.234 for the Faro population. Overall, genetic
variation within R. decussatus populations was high. The total genetic diversity (H
T) was explained by a low variation between populations (G
ST = 0.145), which is consistent with high gene flow (N
m = 2.9). The analysis of molecular variance (AMOVA) showed that 65% of variability is within populations and 35% between populations
(ΦPT = 0.345; P ≥ 0.001). The value of Nei’s genetic distance was 0.0881, showing a low degree of population genetic distance, despite the
different geographic origin. This is the first study on the population genetics of R. decussatus by RAPD technique. The results may be useful for restocking programs and aquaculture. 相似文献