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Stevia rebaudianaBertoni, Asteraceae, is an herbaceous perennial plant native to Paraguay. This species is considered since ancient times a medicinal plant with important bioactive compounds and pharmacologic and food properties, namely diterpenes glycosides. The high natural sweetener potential stevioside and rebaudioside A produced byS. rebaudianaplants are suitable sucrose substitutes, and their obtention is influenced by environmental, phytosociological, and genetic factors. The plants’ genetic profile and sweet potential depiction are needed for suitable plant selection for improvement and deployment. Thirty-oneS. rebaudianaaccessions grown in the same plot where leaves samples were collected in early 2019, were genotyped using six microsatellite markers, including two steviol glycosides biosynthesis functionally involved markers. Additionally, an aqueous extract of each sample was obtained in a water bath and purified by SPE for stevioside and rebaudioside A quantification by normal phase HPLC. Stevioside and rebaudioside A contents varied between 0.53–7.36% (w w−1) and 0.37–3.60% (w w−1), respectively. Two genotypes displayed interesting ratios of rebaudioside A/stevioside (number 3 and 33). The level of genetic similarity between genotypes was tested through a pairwise similarity coefficient, and two groups of individuals had the same fingerprinting. Strong relatedness was found within genotypes, possibly due to cloning, thus, influx of new germplasm ought to be made to prevent mating between relatives, and for further selection and genetic improvement.

Research Highlights: Modelling species’ distribution and productivity is key to support integrated landscape planning, species’ afforestation, and sustainable forest management. Background and Objectives: Maritime pine (Pinus pinaster Aiton) forests in Portugal were lately affected by wildfires and measures to overcome this situation are needed. The aims of this study were: (1) to model species’ spatial distribution and productivity using a machine learning (ML) regression approach to produce current species’ distribution and productivity maps, (2) to model the species’ spatial productivity using a stochastic sequential simulation approach to produce the species’ current productivity map, (3) to produce the species’ potential distribution map, by using a ML classification approach to define species’ ecological envelope thresholds, and (4) to identify present and future key factors for the species’ afforestation and management. Materials and Methods: Spatial land cover/land use data, inventory, and environmental data (climate, topography, and soil) were used in a coupled ML regression and stochastic sequential simulation approaches to model species’ current and potential distributions and productivity. Results: Maritime pine spatial distribution modelling by the ML approach provided 69% fitting efficiency, while species productivity modelling achieved only 43%. The species’ potential area covered 60% of the country’s area, where 78% of the species’ forest inventory plots (1995) were found. The change in the Maritime pine stands’ age structure observed in the last decades is causing the species’ recovery by natural regeneration to be at risk. Conclusions: The maps produced allow for best site identification for species afforestation, wood production regulation support, landscape planning considering species’ diversity, and fire hazard mitigation. These maps were obtained by modelling using environmental covariates, such as climate attributes, so their projection in future climate change scenarios can be performed.

Research Highlights: This study assesses the genetic diversity and structure of the ice-cream-bean (Inga edulis Mart., Fabaceae) in wild and cultivated populations from the Peruvian Amazon. This research also highlights the importance of protecting the biodiversity of the forest in the Peruvian Amazon, to preserve the genetic resources of species and allow further genetic improvement. Background and Objectives: Ice-cream-bean is one of the most commonly used species in the Amazon region for its fruits and for shading protection of other species (e.g., cocoa and coffee plantations). Comprehensive studies about the impact of domestication on this species&rsquo, genetic diversity are needed, to find the best conservation and improvement strategies. Materials and Methods: In the current study, the genetic structure and diversity were assessed by genotyping 259 trees, sampled in five wild and 22 cultivated I. edulis populations in the Peruvian Amazon, with microsatellite markers. Pod length was measured in wild and cultivated trees. Results: The average pod length in cultivated trees was significantly higher than that in wild trees. The expected genetic diversity and the average number of alleles was higher in the wild compared to the cultivated populations, thus, a loss of genetic diversity was confirmed in the cultivated populations. The cultivated trees in the Loreto region had the highest pod length and lowest allelic richness, nevertheless, the wild populations&rsquo, genetic structure was not clearly differentiated (significantly different) from that of the cultivated populations. Conclusions: A loss of genetic diversity was confirmed in the cultivated populations. The species could have been simultaneously domesticated in multiple locations, usually from local origin. The original I. edulis Amazonian germplasm should be maintained. Cultivated populations&rsquo, new germplasm influx from wild populations should be undertaken to increase genetic diversity.

Climate change is already a reality, and habitat loss is affecting relentlessly tree species distributions. The strawberry tree (Arbutus unedo L., Ericaceae) is a Mediterranean evergreen tree used in this article as a case study to evince its expected threatening situation in the upcoming age. This research work seeks to identify the bioclimatic and physiographic variables that have the most impact on the strawberry tree’s spatial distribution in Portugal, acquiring vital knowledge for the design of accurate conservation and afforestation plans for the use and conservation of strawberry tree, working as a guide under a climate change scenario. For that, twenty-one bioclimatic variables, two physiographic attributes (altitude and slope), and the Emberger Index (EI) were used together with 318 observations of strawberry trees, to build a scalable Bayesian procedure, based on machine learning techniques, aimed to assess the species’ future habitat evolution through three temporal scenarios: (i) Control Run (1960–1990); (ii) 2050 and (iii) 2070. The results indicate for 2050 a 30% loss of the humid sub-region and a 35% increase in the semi-arid sub-region towards the north. In 2070, it is expected a 2% recuperation for the sub-humid area, but an 8% loss of the humid sub-area. Under these extreme climate change conditions, it is anticipated an almost complete loss of habitat for the strawberry tree in the south of Portugal. The expected ecological evolvability may trigger future migration paths and new refuges’ settlement in the northern sub-region for the succeeding decades and suggesting after 2070 the possibility of habitat switch and species drifting.

SUMMARYIn marginal lands Opuntia ficus-indica (OFI) could be used as an alternative fruit and forage crop. The plant vigour and the biomass production were evaluated in Portuguese germplasm (15 individuals from 16 ecotypes) by non-destructive methods, 2 years following planting in a marginal soil and dryland conditions. Two Italian cultivars (Gialla and Bianca) were included in the study for comparison purposes. The biomass production and the plant vigour were estimated by measuring the cladodes number and area, and the fresh (FW) and dry weight (DW) per plant. We selected linear models by using the biometric data from 60 cladodes to predict the cladode area, the FW and the DW per plant. Among ecotypes, significant differences were found in the studied biomass-related parameters and several homogeneous groups were established. Four Portuguese ecotypes had higher biomass production than the others, 3.20 Mg ha−1 on average, a value not significantly different to the improved ‘Gialla’ cultivar, which averaged 3.87 Mg ha−1. Those ecotypes could be used to start a breeding program and to deploy material for animal feeding and fruit production.

Increasing forest wildfires in Portugal remain a growing concern since forests in the Mediterranean region are vulnerable to recent global warming and reduction of precipitation. Therefore, a long-term negative effect is expected on the vegetation, with increasing drought and areas burnt by fires. The strawberry tree (Arbutus unedo L.) is particularly used in Portugal to produce a spirit by processing its fruits and is the main income for forestry owners. Other applications are possible due to the fruit and leaves’ anti-oxidant properties and bioactive compounds production, with a potential for clinical and food uses. It is a sclerophyllous plant, dry-adapted and fire resistant, enduring the Mediterranean climate, and recently considered as a possibility for afforestation, to intensify forest discontinuity where pines and eucalypts monoculture dominate the region. To improve our knowledge about the species’ spatial distribution we used 318 plots (the centroid of a 1 km2 square grid) measuring the species presence and nine environmental attributes. The seven bioclimatic variables most impacting on the species distribution and two topographic features, slope and altitude, were used. The past, current and future climate data were obtained through WorldClim. Finally, the vulnerability of the strawberry tree to the effects of global climate change was examined in the face of two emission scenarios (RCP 4.5 and 8.5), to predict distribution changes in the years 2050 and 2070, using a species distribution models (MaxEnt). The reduction of suitable habitat for this species is significant in the southern regions, considering the future scenarios of global warming. Central and northern mountainous regions are putative predicted refuges for this species. Forest policy and management should reflect the impact of climate change on the usable areas for forestry, particularly considering species adapted to the Mediterranean regions and wildfires, such as the strawberry tree. The distribution of the species in the Last Glacial Maximum (LGM) and Mid-Holocene (MH) agrees with previous genetic and paleontological studies in the region, which support putative refuges for the species. Two in the southern and coastal-central regions, since the LGM, and one in the east-central mountainous region, considered as cryptic refugia. Fundação para a Ciência e a Tecnologia | Ref. UID/AGR/00239/2013 Fundação para a Ciência e a Tecnologia | Ref. SFRH/BSAB/113895/2015 Fundação para a Ciência e a Tecnologia | Ref. UID/AMB/00681/2013 Fundação para a Ciência e a Tecnologia | Ref. SFRH/BSAB/127907/2016 Fundação para a Ciência e a Tecnologia | Ref. UID/AGR/00239/2013 Fundação para a Ciência e a Tecnologia | Ref. UID/AGR/04129/2013 Fundação para a Ciência e a Tecnologia | Ref. UID/AMB/00681/2013 Fundação para a Ciência e a Tecnologia | Ref. UID/AMB/00681/2013

In Opuntia spp., the cladode tissues contain many polysaccharides and secondary metabolites that interfere with obtaining high-quality deoxyribonucleic acid (DNA), using currently available methods. To circumvent this problem, three commercial kits, three modified versions of the conventional cetyltrimethylammonium bromide method (CTAB) method and one combined method were tested in Opuntia ficus-indica, O. robusta, O. dillenii and O. elata species. We obtained a rapid and simple protocol that allows the extraction of DNA from all the tested species with good DNA yield and purity, namely, the combined method. With this method (DNeasy® Plant Mini Kit combined with the CTAB method), DNA yields from 13.2 ± 7.8 to 15.9 ± 11.3 µg g−1 of fresh tissue were obtained in the four Opuntia species. The purity, evaluated by the ratio A260/A280 ratio, ranged from 1.67 ± 0.12 to 2.01 ± 0.25, revealing low levels of problematic metabolites. The extracted DNA quality was confirmed by amplifying a set of nuclear microsatellites obtained for the genus. Reliable reproducible bands and electropherogram profiles were obtained. The combined method has potential to be universal for good-quality DNA extraction in cacti, particularly in the Opuntia genus and other difficult-to-extract species.

Olea europaea ssp. europaea (Oleaceae) grows in Mediterranean countries. The Galega represents one of the most common Portuguese olive tree cultivars, and is used in five out of the six PDO (Protected Designation of Origin) regions. The fruits are used for olive oil and for fruit canning, besides which the cultivar is drought tolerant. The cultivar certification is done through phenotypic characteristics, but environmental influence might blur informativeness, and molecular markers could help in clarifying cultivar accessions certification. A total of 75 putative Galega accessions considered as belonging to the Galega cultivar, three previously phenotypically identified as GGN (Galega Grada Normal), GGS (Galega Grada de Serpa) and GGE (Galega Grada de Evora), and one as a non-Galega blind control were analyzed. Twenty RAPD primers amplified 144 bands and 32% were polymorphic. A low expected heterozygosity was estimated (10%), as expected for clonal propagated plants. The Principal Component Analysis (PCA) clearly identified two groups. Group A was comprised of all the putative Galega accessions including GGN, but not individual #502. Group B included NG, GGE, GGS and #502. The analysis of molecular variance confirmed a very high differentiation between the two groups (88%), but also some within groups’ diversity (12%). Group A individuals cluster closely to GGN. Assuming that the GGN individual represents a Galega cultivar tree, we might assume that all the A group trees are Galega cultivar accessions. Nevertheless, some within group variability exists, may be due to the accumulation of somatic mutations and/or a putative origin from different, but related genotypes. Finally, the GGS, the GGE, and the #502 plot together with the individual identified as non Galega cultivar tree. Group B trees certainly had a very different genetic origin compared to the group A genotypes, which confirms some differences found in the morphologic characteristics compared to the ordinary Galega cultivar, reflected in the name differences. The pairwise matrix computed with the Dice similarity index was also used to obtain a dendrogram. Results were similar, but slightly different from the PCA. Three clusters were obtained. This indicates that the B group could be split into two sub-groups. A future study using a broader sampling and higher discriminant molecular markers, such as microsatellites, would help to reveal the phylogeny among the 3 cultivars (GGN, GGS and GGE) and to clarify if the intra-variability of those cultivars is geographically related.

Mediterranean forests are fragile ecosystems vulnerable to recent global warming and reduction of precipitation, and a long-term negative effect is expected on vegetation with increasing drought and in areas burnt by fires. We investigated the spatial distribution of genetic variation of Arbutus unedo in the western Iberia Peninsula, using plastid markers with conservation and provenance regions design purposes. This species is currently undergoing an intense domestication process in the region, and, like other species, is increasingly under the threat from climate change, habitat fragmentation and wildfires. We sampled 451 trees from 15 natural populations from different ecological conditions spanning the whole species' distribution range in the region. We applied Bayesian analysis and identified four clusters (north, centre, south, and a single-population cluster). Hierarchical AMOVA showed higher differentiation among clusters than among populations within clusters. The relatively low within-clusters differentiation can be explained by a common postglacial history of nearby populations. The genetic structure found, supported by the few available palaeobotanical records, cannot exclude the hypothesis of two independent A. unedo refugia in western Iberia Peninsula during the Last Glacial Maximum. Based on the results we recommend a conservation strategy by selecting populations for conservation based on their allelic richness and diversity and careful seed transfer consistent with current species' genetic structure. info:eu-repo/semantics/publishedVersion

The strawberry tree (Arbutus unedo L.) is an underutilized, drought tolerant, fire resistant species with a south western distribution in Europe, and with ecological and putative socio-economical impact in Portugal and Mediterranean countries. Our aim was to develop an appropriate set of molecular markers to enable genetic diversity to be assessed and to fingerprint Arbutus unedo genotypes for breeding and conservation purposes in Portugal. Twenty-seven trees from a broad geographic range were screened with 20 random amplified polymorphic DNA (RAPD primers) and 11 microsatellite markers (SSR). The RAPDs generated 124 bands, 57.3% of which were polymorphic, with an expected heterozygosity of 27%. We cross-amplified 11 SSR primers developed for Vaccinium spp., and 5 were found to be polymorphic in A. unedo, with 75% of expected heterozygosity, a number of alleles of 11.6, a null allele frequency of 7.6% and a polymorphic information content of 71%. Although the SSRs were more polymorphic and informative than the RAPDs, both markers displayed high genetic variability with the gathered data. No geographic pattern was observed in the genetic variation distribution based on both marker systems, and the lack of correlation between genetic and geographical matrices was confirmed by Mantel tests. Likely, no correlation was found between pairwise SSR and RAPD band-sharing matrices. These results and their implications on A. unedo breeding and conservation programs are discussed.

To assess the genetic patterns of colonisation of metalliferous areas by the pseudometallophyte Cistus ladanifer with AFLP genome scan, to compare those estimates with previous cpSSR results, and to identify loci potentially linked to tolerance to metalliferous soils. Thirty-three populations were screened with AFLP markers. Statistical analyses included estimation of genetic diversity, hierarchical analysis of molecular variation and Bayesian analysis of geographical partitioning of genetic diversity. Mantel tests and Spearman’s correlation index were used to compare results obtained with AFLP and cpSSR. Generalized Estimating Equations (GEE) models were applied to correlate allele frequency distribution and soil variables (pH, Ca:Mg ratio and total contents of different trace metals). Metallicolous and non-metallicolous populations of C. ladanifer showed neither different levels of genetic diversity, nor genetic differentiation between population types. Incongruence in genetic diversity estimates between AFLP and cpSSR due to marker-specific properties was observed. Nonetheless, pairwise distance matrices computed with both markers were concordant. GEE analyses showed that the Mn total soil content has an important effect on the allele distribution in C. ladanifer. In contrast, the Ca:Mg ratio seems to have no selective effect. Moreover, we identified a particular band with a putative role in the species’ tolerance to high Mn concentrations in the soil. The soil type had no influence over this species’ genetic structure. GEE showed their usefulness in revealing the association between soil variables and AFLP loci.

International audience; AbstractKey messageSlash and burn practices affect tropical forests. Our results showed strong introgression between Inga ingoides and Inga edulis in the species contact area. Interspecific hybridization could be sought to improve yield and tolerance to flooding and further increase the economic potential of the poorly drained Amazonian soils and minimize deforestation.ContextInga species are important components of tropical American forests, as well as a local food source. Little is known about the genetic structure of these species; in particular the amount of introgression among species remains unknown.AimsWe assessed the degree of genetic divergence and introgression among populations of I. ingoides (Rich.) Willd. and I. edulis Mart. (Fabaceae) from three Peruvian Amazon tributary rivers.MethodsUsing microsatellite markers we determined the genetic structure of populations using an analysis of molecular variance and a Bayesian analysis of population structure in areas affected by seasonal river fluctuations and in ‘terra firme’ forests.ResultsOverall genetic differentiation was weak. The degree of genetic variation was similar in the two species. A putatively strong introgression was detected between the two species and an intense gene flow was identified among populations. This indicates that an intense gene flow had happened in the past, leading also to a small differentiation among populations within species.ConclusionSelection of natural hybrids or artificial hybridization between I. edulis and I. ingoides could be applied to improve legume size and yield in the later species, while maintaining tolerance to flooding. Improved I. ingoides could be used in multipurpose agroforestry on open areas along the rivers, instead of using the usual slash and burn practice to create inland open areas.

International audience; • Introduction Tree genetic improvement programs usually lack, in general, pedigree information. Since molecular markers can be used to estimate the level of genetic similarity between individuals, we genotyped a sample of a Portuguese Eucalyptus globulus breeding population—a reference population of 125 individuals—with 16 microsatellites (SSR). • Materials and methods Using genotypes from the reference population, we developed a simulation approach to recurrently generate (105 replicates) virtual offspring with different relatedness: selfed, half-sib, full-sib and unrelated individuals. Four commonly used pairwise similarity coefficients were tested on these groups of simulated offspring. Significant deficits in heterozygosity were found for some markers in the reference population, likely due to the presence of null alleles. Therefore, the impact of null alleles in the relatedness estimates was also studied. We conservatively assumed that all homozygotes in the reference population were carriers of null alleles. • Results All estimators were unbiased, but one of them was better adjusted to our data set, even when null alleles were considered. The estimator’s accuracy and precision were validated with individuals of known pedigree obtained from controlled crosses made with the same reference population’s parents. Additionally, a clustering algorithm based on the estimator of choice was constructed, in order to infer the relatedness among 24 E. globulus elite individuals. We detected four putatively related elite individuals’ pairs (six pairs considering the presence of null alleles). • Conclusions This work demonstrates that in the absence of pedigree information, our approach could be useful to identify relatives and minimize consanguinity in breeding populations.

Some 1339 trees from 48 Pinus pinaster stands were characterized by five chloroplast microsatellites, detecting a total of 103 distinct haplotypes. Frequencies for the 16 most abundant haplotypes (pk > 0.01) were spatially interpolated over a lattice made by 430 grid points. Fitting of spatially interpolated values on raw haplotype frequencies at the same geographical location was tested by regression analysis. A range-wide 'diversity map' based on interpolated haplotype frequencies allowed the identification of one 'hotspot' of diversity in central and southeastern Spain, and two areas of low haplotypic diversity located in the western Iberian peninsula and Morocco. Principal component analysis (PCA) carried out on haplotypes frequency surfaces allowed the construction of a colour-based 'synthetic' map of the first three PC components, enabling the detection of the main range-scale genetic trends and the identification of three main 'gene pools' for the species (i) a 'southeastern' gene pool, including southeastern France, Italy, Corsica, Sardinia, Pantelleria and northern Africa; (ii) an 'Atlantic' gene pool, including all the western areas of the Iberian peninsula; and (iii) a 'central' gene pool, located in southeastern Spain. Multivariate and amova analyses carried out on interpolated grid point frequency values revealed the existence of eight major clusters ('gene zones'), whose genetic relationships were related with the history of the species. In addition, demographic models showed more ancient expansions in the eastern and southern ranges of maritime pine probably associated to early postglacial recolonization. The delineation of the gene zones provides a baseline for designing conservation areas in this key Mediterranean pine. © 2007 The Authors.

Pinus pinaster is a conifer native to western Europe and northern Africa. Following on-going breeding programmes, provenance and progeny trials were established in some of the countries of the species' range (France, Portugal and Spain) and quantitative traits were measured growth, stem form, survival and pest and disease resistance, amongst others. Populations from the wide range of P. pinaster were recently screened with molecular markers in order to assess their genetic diversity. Data were obtained using allozymes, chloroplast (cpSSRs) and nuclear (nuSSRs) microsatellites and amplified fragment length polymorphisms (AFLPs). Based on mtDNA-RFLP analysis, three maternal lineages (named "western", "eastern" and "Moroccan") were identified and no population showed a mixed composition. In this study, the imprint that differentiation in putatively isolated glacial refugia (identified by the different maternal lineages) might have left on the nuclear genome was analysed using a wide range of molecular markers and adaptive traits. Multivariate ordination of populations based on nuclear molecular markers (allozymes and nuSSRs) showed a clear clustering of provenances sharing a given mtDNA lineage. However, that clustering was found to be less tight when only quantitative traits were investigated. In P. pinaster, the within-population estimates of gene diversity using different traits were not correlated. Therefore, caution is advisable when designing conservation strategies based on molecular marker studies or a limited number of populations. After these results, we recommend a conservation strategy characterised by gene flow consistent with the current population structure, careful seed transfer among maternal lineages (if any), selection of populations for conservation based on the originality of their allelic composition and definition of Management Units (MUs) based on adaptive traits. © 2004 Elsevier B.V. All rights reserved.

International audience; Maritime pine (Pinus pinaster Ait.) is the first conifer used for reforestation in France and now covers 2.4 million ha of the Iberian Peninsula. In order to preserve the genetic resources of this economically and ecologically important species prior knowledge of the distribution of genetic diversity is needed. In this paper, a genetic diversity study was performed using nuclear simple sequence repeats (SSRs or microsatellites). Classical parameters of diversity (allelic richness and heterozygosity) and differentiation were estimated for 47 populations of P. pinaster. Most of the populations (40) were collected in France, six populations were also collected in the Iberian Peninsula and one Moroccan population was also included in the study. The population genetic parameters indicated that some populations should be a focus of conservation efforts (higher level of diversity, higher allelic richness and presence of rare alleles). A diagnostic test for sample origin was developed to distinguish Corsican from Landes populations.; Que nous indiquent les microsatellites nucléaires sur la conservation des ressources génétiques du pin maritime et sur les stratégies de certification de provenances ? Le pin maritime (Pinus pinaster Ait.) est le premier conifère utilisé pour le reboisement en France et couvre environ 2,4 millions d'hectares dans la péninsule Ibérique. Dans le but de conserver les ressources génétiques de cette espèce, importante du point de vue économique et écologique, une connaissance préalable de la distribution de sa diversité génétique est nécessaire. Dans ce papier, une étude de diversité génétique a été menée en utilisant des marqueurs microsatellites. Les paramètres classiques de diversité (richesse allélique et hétérozygotie) et de différenciation ont été calculés au sein de 47 populations. La plupart des populations (40) ont été échantillonnées en France, six populations ont été choisies dans la Péninsule Ibérique et une population marocaine a également été incluse dans l'analyse. Les résultats de génétique des populations montrent que certaines populations pourraient être intéressantes pour la conservation des ressources génétiques de l'espèce (niveau d'hétérozygotie ou de richesse allélique plus élevée que les autres populations, présence d'allèles rares). Nous avons montré que les résultats de cette analyse fournissent un test diagnostic pour distinguer les populations d'origine landaise des populations d'origine corse.

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.

International audience; Maritime pine seed-lots from north-western Iberian regions (Portugal and Galicia) were introduced in the 1950s to the south-west of France (Aquitaine region), and the stands they formed suffered considerable frost damage. In the mid 1980s, a biochemical test was developed to test the putative origin of adult stands in Aquitaine, before seeds could be distributed for commercial purposes in France. In this paper, we describe a new test employing chloroplast simple-sequence repeats (cpSSRs) to facilitate identification of stand origin based on randomisation tests. The origin of five stands of unknown origin was determined with both the cpSSR and biochemical (terpene profile analysis) tests. The results from the two tests were concordant, but the DNA-based test gave faster and more accurate results. Use of this test should help when determining the origin of maritime pine stands in the Aquitaine region of France.; Des lots de graines du nord ouest de la péninsule ibérique (Portugal et Galice) ont été introduits dans les années 1950 dans le sud-ouest de la France (Aquitaine), et les peuplements issus de ces graines ont fortement souffert des gelées. Un test variétal basé sur les marqueurs terpéniques fut développé dans les années 1980 afin d'identifier l'origine géographique des peuplements adultes en Aquitaine sur lesquels des graines étaient récoltées puis commercialisées. Dans cet article nous décrivons un nouveau test qui utilise des marqueurs microsatellites chloroplastiques (cpSSRs) et simulations pour identifier l'origine des peuplements. Une étude comparative des tests biochimique (terpènes) et cpSSR a été menée sur cinq peuplements adultes. Les résultats obtenus sont identiques, mais le test ADN s'est avéré plus rapide et plus précis. L'utilisation de ce nouveau test devrait permettre de garantir l'origine géographique des peuplements de pin maritime du sud-ouest de la France (Aquitaine).