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SummaryClimate change alters relationships among environmental conditions and thus has the potential to change the selection pressures acting on adaptive gene variants. Using a landscape genomic approach, we show that the southern beech speciesNothofagus pumiliohas notable genetic adaptations to climate along its 2000-kilometer-long range in the Andes. We screened 47,336 SNP loci in 1,632 contigs and found that high-latitude sampling sites have lower genetic diversity, likely due to greater impact of glacial oscillations at high latitudes. Using four genome scan methods, we identified 457 outlier SNPs that are either strongly differentiated among subpopulations or associated with environmental covariates related to temperature, day length, and precipitation. Temperature and day length parameters were associated with notably more outliers than precipitation (n = 133, 113, and 61 outliers, respectively), and almost half of all annotated outliers were related to stress response (n=38, 21%) or catabolism-metabolism (n=43, 24%). Our findings suggest thatNothofagus pumiliois an ideal Andean model of genetic adaptation to climate change because it is locally adapted to extant climate conditions, and shifting patterns among environmental parameters may be detrimental to its future survival and adaptation potential.

Suillus luteus is a common ectomycorrhizal (EM) fungus associated with several Pinus species. It is distributed throughout the Northern Hemisphere and has been introduced into South America and New Zealand. We examined the genetic structure and population biology of S. luteus, which was introduced into Patagonian plantations with Pinus species in Argentina. Overall, 106 samples were collected at 11 geographically separated sites (i.e., Pinus plantations) along a latitudinal gradient in Patagonia (ca. 38°–46° south latitude). Phylogenetic analyses confirmed placement in S. luteus. Genetic analysis demonstrated moderate within-site genetic diversity, but low differentiation between sites. No clear clusters were detected geographically or in relation to host species of Pinus. Our results suggest that the weak genetic structure of the species reflects the short time that has elapsed since the introduction of S. luteus into Patagonia, and its expansion with exotic afforestation there. Moreover, the lack of structure is consistent with a founder effect, suggesting the introduction of a small number of genets that spread throughout all the plantations. Therefore, the high level of gene flow and weak genetic structure observed are probably related to the anthropogenic movement of inoculum associated with forestry practices.

The resistance of different genotypes to abiotic stress may be due to genetic effects and/or to phenotypic plasticity allowing them to acclimate to variable conditions. The contribution of one or the other mechanism determines different strategies with implications for the species conservation and adaptive management. In this study, the ecophysiological response to drought of Nothofagus pumilio provenance sites (humid, mesic and xeric) from contrasting precipitation regimes was evaluated in a common garden trial. Seedlings were submitted to progressive drought by withdrawing irrigation (control vs water deficit). Assuming a genetic base determined by selection pressures, populations from more xeric sites are expected to show higher resistance to drought, e. g., higher resistance to xylem cavitation and safety margin, stronger stomatal control and osmotic adjustment. Vulnerability to cavitation curves were performed, and the percentage loss of conductivity (P12, P50, P88 and slope) was obtained. The water potential at turgor loss point (TLP) and the osmotic potential at full turgor (π100) were calculated from pressure–volume curves. The humid site showed a significantly higher P50 value than the mesic and the xeric sites. Pre-dawn water potential differed between the provenances from xeric and mesic conditions under severe water deficit. Natural selection was inferred from the comparison of differentiation at neutral markers and phenotypic traits (FST vs. PST), with signals of adaptive variation (PST > FST) for stomatal density, specific leaf area, TLP, π100 and stomatal conductance. Results suggest a differential adaptive capacity to drought of N. pumilio provenance sites that could be evidencing local adaptation to their home environment.

Key message: Nothofagus alpina (Poepp. et Endl.) Oerst. and Nothofagus obliqua (Mirb.) Oerst forests have strong fine-scale spatial genetic structures. The intensity of genetic structure patterns differed according to species, stand development stages, life stages, and spatial arrangement of regeneration groups. This data becomes useful for forest management as it provides an understanding of how populations evolve as well as of the consequences of disturbances and enables the establishment of sampling strategies. Context: The understanding of fine-scale spatial genetic structure in natural populations is useful for forest management. Although Nothofagus alpina (Poepp. et Endl.) Oerst. and N. obliqua (Mirb.) are important species of the Patagonian forest, little is known about the genetic structure of their populations. Aims: The main objectives were to investigate the differences in fine-scale spatial genetic structure among mature tree populations of both species considering two stands at different development stages. Genetic structure was also evaluated among life stages and spatial distribution groups of regeneration within the old-growth stand. Methods: Genetic structure was examined by microsatellite DNA analysis of regeneration and mature tree populations of both species (around 1300 individuals). Gene dispersal distance was additionally estimated. Results: In both stands and species, strong fine-scale spatial genetic structure and short dispersal distance were found. This pattern was stronger in the early successional forest, in N. obliqua populations, in earlier life stages, and in scattered regeneration. Conclusion: Stand development stages and recruitment patterns influence the fine-scale spatial genetic structure of both Nothofagus species. However, the genetic structure also differs between species. Estación Experimental Agropecuaria Bariloche Fil: Sola, Georgina. Universidad Nacional del Comahue; Argentina Fil: Sola, Georgina. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina Fil: Marchelli, Paula. Instituto Nacional de Tecnologia Agropecuaria (INTA). Estacion Experimental Agropecuaria Bariloche. Grupo de Ecologia Forestal; Argentina Fil: Marchelli, Paula. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; Argentina Fil: Gallo, Leonardo Ariel. Instituto Nacional de Tecnologia Agropecuaria (INTA). Estacion Experimental Agropecuaria Bariloche. Area Forestal; Argentina Fil: Chauchard, Luis. Universidad Nacional del Comahue; Argentina Fil: El Mujtar, Veronica Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentina Fil: El Mujtar, Veronica Andrea. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; Argentina

Understanding the impact of management on the dispersal potential of forest tree species is pivotal in the context of global change, given the implications of gene flow on species evolution. We aimed to determine the effect of logging on gene flow distances in two Nothofagus species from temperate Patagonian forests having high ecological relevance and wood quality. Therefore, a total of 778 individuals (mature trees and saplings) of Nothofagus alpina and N. obliqua, from a single plot managed 20 years ago (2.85 hectares), were mapped and genotyped at polymorphic nuclear microsatellite loci. Historical estimates of gene dispersal distance (based on fine-scale spatial genetic structure) and contemporary estimates of seed and pollen dispersal (based on spatially explicit mating models) were obtained. The results indicated restricted gene flow (gene distance ≤ 45 m, both pollen and seed), no selfing and significant seed and pollen immigration from trees located outside the studied plot but in the close surrounding area. The size of trees (diameter at breast height and height) was significantly associated with female and/or male fertility. The significant fine-scale spatial genetic structure was consistent with the restricted seed and pollen dispersal. Moreover, both estimates of gene dispersal (historical and contemporary) gave congruent results. This suggests that the recent history of logging within the study area has not significantly influenced on patterns of gene flow, which can be explained by the silviculture applied to the stand. The residual tree density maintained species composition, and the homogeneous spatial distribution of trees allowed the maintenance of gene dispersal. The short dispersal distance estimated for these two species has several implications both for understanding the evolution of the species and for defining management, conservation and restoration actions. Future replication of this study in other Nothofagus Patagonian forests would be helpful to validate our conclusions.

Significant gaps remain in understanding the response of plant reproduction to environmental change. This is partly because measuring reproduction in long-lived plants requires direct observation over many years and such datasets have rarely been made publicly available. Here we introduce MASTREE+, a data set that collates reproductive time-series data from across the globe and makes these data freely available to the community. MASTREE+ includes 73,828 georeferenced observations of annual reproduction (e.g. seed and fruit counts) in perennial plant populations worldwide. These observations consist of 5971 population-level time-series from 974 species in 66 countries. The mean and median time-series length is 12.4 and 10 years respectively, and the data set includes 1122 series that extend over at least two decades (≥20 years of observations). For a subset of well-studied species, MASTREE+ includes extensive replication of time-series across geographical and climatic gradients. Here we describe the open-access data set, available as a.csv file, and we introduce an associated web-based app for data exploration. MASTREE+ will provide the basis for improved understanding of the response of long-lived plant reproduction to environmental change. Additionally, MASTREE+ will enable investigation of the ecology and evolution of reproductive strategies in perennial plants, and the role of plant reproduction as a driver of ecosystem dynamics. EEA Santa Cruz Fil: Hacket-Pain, Andrew. University of Liverpool. School of Environmental Sciences. Department of Geography and Planning; Reino Unido Fil: Foest, Jessie J. University of Liverpool. School of Environmental Sciences. Department of Geography and Planning; Reino Unido Fil: Pearse, Ian S. U.S. Fort Collins Science Center. Geological Survey; Estados Unidos Fil: LaMontagne, Jalene M. DePaul University. Department of Biological Sciences; Estados Unidos Fil: Koenig, Walter D. University of California Berkeley. Hastings Reservation; Estados Unidos Fil: Vacchiano, Giorgio. University of Milan. Milan Department of Agricultural and Environmental Sciences; Italia. Fil: Bogdziewicz, Michał. Adam Mickiewicz University. Faculty of Biology. Institute of Environmental Biology; Polonia Fil: Bogdziewicz, Michał. University Grenoble Alpes. INRAE, LESSEM; Francia Fil: Caignard, Thomas. Université Bordeaux. INRAE, BIOGECO; Francia Fil: Celebias, Paulina. Adam Mickiewicz University. Faculty of Biology. Institute of Environmental Biology; Polonia Fil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina. Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral; Argentina. Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fil: Ascoli, Davide. University of Torino. Department of Agricultural. Forest and Food Sciences (DISAFA); Italia Fil: Gallo, Leonardo Ariel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentina Fil: Gallo, Leonardo Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; Argentina Fil: Marchelli, Paula. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentina Fil: Marchelli, Paula. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; Argentina

Seed germination is one of the earliest phenotypes expressed by plants, and the accuracy to germinate in the correct time and place is essential for plant population fitness. Cues that regulate germination have been exhaustively characterized in laboratory experiments. However, the way in which seed populations respond to these cues and the ecological meanings of this phenomenon are scarcely known. To help filling this gap, we studied the thermic regulation of seed germination and its link with local climatic characteristics in Festuca pallescens populations, an iconic perennial grass species of Patagonia. By coupling thermal time models with field and environmental data, we evaluated seed responsiveness to temperature during germination of nine Festuca pallescens populations distributed across their complete longitudinal range in North Patagonia. The idea behind this experimental design was to search for inter-population differences in early life traits relevant for recruitment of the species, and associate seed traits with local environmental characteristics. F. pallescens populations showed strong differences in seed sensitivity to temperature for the thermal regulation of the germination rate, described by the population mean thermal time for germination (θ(50)) and its standard deviation (σθ). The greatest values of θ(50) and σθ corresponded to populations inhabiting harsh environments. Moreover, θ(50) of the different populations showed strong correlations with their local thermal environmental parameters, indicating a relation between seed physiological traits and climate across the longitudinal gradient. We did not observe inter-population differences in the minimum temperature that allows germination (Tb = -0.47 ± 0.19 °C). Higher θ(50) and σθ in populations from harsh climates may constitute a strategy of the species to increase fitness in hostile habitats, preventing anticipated germination and promoting a slower seed bank depletion in regions where establishment is highly limited.

Global warming is predicted to exert negative impacts on plant growth due to the damaging effect of high temperatures on plant physiology. Revealing the genetic architecture underlying the heat stress response is therefore crucial for the development of conservation strategies, and for breeding heat-resistant plant genotypes. Here we investigated the transcriptional changes induced by heat in Nothofagus pumilio, an emblematic tree species of the sub-Antarctic forests of South America. Through the performance of RNA-seq of leaves of plants exposed to 20°C (control) or 34°C (heat shock), we generated the first transcriptomic resource for the species. We also studied the changes in protein-coding transcripts expression in response to heat. We found 5,214 contigs differentially expressed between temperatures. The heat treatment resulted in a down-regulation of genes related to photosynthesis and carbon metabolism, whereas secondary metabolism, protein re-folding and response to stress were up-regulated. Moreover, several transcription factor families like WRKY or ERF were promoted by heat, alongside spliceosome machinery and hormone signaling pathways. Through a comparative analysis of gene regulation in response to heat in Arabidopsis thaliana, Populus tomentosa and N. pumilio we provide evidence of the existence of shared molecular features of heat stress responses across angiosperms, and identify genes of potential biotechnological application.

This chapter deals with two emblematic species of the Argentine forests: Araucaria araucana, a conifer with a restricted distribution area and considered a living fossil, and Salix humboldtiana, a willow with a continental distribution but the only native to this country and particularly threatened in Patagonia. Each species is presented in a separate subchapter (7.1 and 7.2). For each species the main characteristics as well as natural distribution, ecology and reproductive biology are fully described. State of knowledge of the molecular genetic diversity at landscape level together with genetic variation at adaptive traits provide a general picture of the genetic structure of each species. Both are at risk of extinction due to past overexploitation, and different anthropogenic pressures currently menace their conservation. Araucaria araucana is protected under the red list of CITES, so its logging is forbidden. However, climate change, increase of habitat fragmentation and livestock pressure are threatening its persistence. Social and cultural aspects are also discussed, with particular reference to the traditional use of these species; the sacred nature of Pewen for the Mapuche Nation is highlighted. Regarding the native willow, a genetic swamping process caused by the invasion of exotic willows along the Patagonian rivers is described. They have the ability to hybridize spontaneously. Restoration, conservation and breeding strategies are related both with timber and non-timber forest products. The particular case of conservation through use in A. araucana is shown.

Nothofagus obliqua forests in Argentina extend over a wide latitudinal gradient but highly fragmented and locally restricted. The relevance of this species relies in its high wood quality and tolerance to warmer niches, as those predicted under climate change. In this chapter, we describe the species characteristics and natural distribution range as well as the natural hybridisation process that occurs frequently with other Nothofagus species. Genetic variation patterns based on neutral genetic markers (isozymes, cpDNA and microsatellites) allowed inferring past demographic changes during the Pleistocene glaciations. In addition, the level of genetic diversity was used as an indicator for conservation and for the definition of genetic zones as seed sources for breeding and restoration. Quantitative genetic variation and phenotypic plasticity measured at seeds, seedling and juvenile states on nursery and field trials gave insights about adaptation. The first steps towards breeding of roble pellin in Argentina are fully described: provenance and progeny tests and seed producing areas, both natural and cultivated ones. Intra- and interspecific-controlled crossings of N. obliqua represent a fundamental step towards the breeding of this species, and the first achievements are described.

Nothofagus pumilio and N. antarctica are main components of the Andean Patagonian Temperate forests that occur along all the environmental gradients that characterize the Patagonian region. In this chapter, their main botanical features and natural ranges are presented, as well as the state of the art in genetic studies. Phylogeographic patterns based on chloroplast DNA help inferring Pleistocene refugia location and colonization pathways. Both species share haplotypes, and interspecific hybridization occurs naturally. A genetic structure analysis through genomic microsatellites shows latitudinal trends, species admixture, and contact zones. Selective logging evidences an effect on patterns of genetic diversity in N. pumilio. The definition of genetic zones contributes to the conservation and management of the genetic resources of both species. In addition, quantitative genetic variation and phenotypic plasticity are analyzed under nursery and field conditions, in juvenile morphological, phenological, physiological, and growth rhythms traits. Ecotypic variation was detected along longitudinal and altitudinal gradients of N. pumilio. Finally, the domestication and development of low intensity breeding strategies are presented, including a provenance trial network and seed production areas of N. pumilio, and progeny seed orchards of N. antarctica.

Planting native species requires particular genetic considerations in order to minimize the risks of maladaptation and genetic contamination. Outbreeding depression and genetic swamping are possible processes that should be avoided. Authenticity and functionality are two opposing objectives in active restoration of degraded ecosystems. Actual examples of genetic risks in Argentina regarding native species plantation are presented. Climate change is a deep conditioning of tree plantation, and according to the forecast for Argentina a future shifting in the natural range of forest tree species is expected. An example through ecological niche modeling in two Nothofagus species shows possible outcomes of this shift. Another example based on threshold models determining timing of germination describes possible altitudinal shifts. Assisted migration and assisted gene flow are potential resources to mitigate the impact of climate change: should we breed for the present or for the future climate? The dilemma of facing the risk of extinction through a risk of invasion.

Rauli is an iconic species of the temperate sub-Antarctic forests due to its hardwood quality of pinkish tones. Because of its ecological and economic relevance, it is under conservation within national parks and being domesticated for plantation purposes. In this chapter, we present the state of the art of the species in Argentina. General features as distribution, biology and uses are firstly presented. Patterns of genetic variation at neutral markers allowed studying the legacy of the glacial ages as well as recent processes shaping the genetic structure. In addition, variation among populations at quantitative traits (phenological, physiological, morphological, architectural and growth rhythm traits) reflect the action of natural selection. Mycorrhizas and other soil fungi have strong relevance for conservation and domestication programmes, and their diversity is described. The domestication programme is dependent on seed productivity restrictions in natural stands, and the regulation of germination was studied through threshold models. The breeding strategy of rauli includes provenance and progeny tests, definition of genetic zones and seed collection areas based on genetic markers and installation of progeny seed orchards. Conservation and management of N. alpina forests in Argentina is finally discussed in the context of its over-exploitation in the past decades, conservation actions and management guidelines.

The Andean-Patagonian forests are the southernmost temperate forests in the world spreading over a thin strip at both sides of the Andes Mountains. This chapter introduces to a section of the book devoted to different species of these forests. Generalities and particularities of the Andean-Patagonian forests such as disturbs, endemisms, and drastic environmental gradients are described. The distribution patterns of forest tree species are determined by latitudinal, longitudinal, and altitudinal gradients, creating ideal models for studying processes of adaptation. Social aspects cannot be neglected; the value of conserving forest genetic resources of a highly touristic region, the overexploitation in the past, and the pressure of real estate speculation for the change of forestland use are issues that oppose each other. In addition, the claim of rights of “pueblos originarios” over natural forests gave origin to the co-management in the Lanin National Park. General concepts about the main tree species of the Andean-Patagonian forests of Argentina are presented: shared patterns in the distribution of the genetic variation, modeling of the genetic patterns by glaciations, volcanism, and wind, general state of knowledge about their genetic diversity at neutral markers, and adaptive traits. We concluded with describing the species chosen for breeding and postfire restauration initiatives.

Context: Clinal genetic variation in natural populations could reflect either recent demographic history or the evolution of adapted genotypes along heterogeneous environments.Aims: We describe genetic variation patterns in three Nothofagus species of South American temperate forests, growing along steep rainfall gradients. Our hypothesis is that the selection pressure along this gradient reinforces the genetic structure previously shaped by Pleistocene climate oscillations. Methods: We screened variation along gradients at putative adaptive markers: candidate genes involved in response to drought, and EST-SSRs linked to drought stress genes. Genomic SSRs (gSSRs) were used to decouple the incidence of demographic events in the genetic structure.Results: Genetic diversity at SSRs agreed with the putative location of cryptic Pleistocene refugia in Nothofagus. In addition, each species showed different trends for nucleotide diversity at candidate genes. Unbiased heterozygosity significantly correlated with precipitation at EST-SSRs in N. nervosa. We found evidences of balancing selection and several SNPs departed from neutral expectations.Conclusions: Nothofagus genetic variability shows a strong imprint of demographic changes that reveals refugia location for the species during Pleistocene. This variability is modelled by environmental conditions across natural gradients, which impose selection pressure at genome regions related to stress response, providing clues about inter-specific differences in adaptive potential to water deficit. Fil: Soliani, Carolina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche. Instituto de Investigaciones Forestales y Agropecuarias Bariloche. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; Argentina Fil: Azpilicueta, María Marta. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche. Instituto de Investigaciones Forestales y Agropecuarias Bariloche. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; Argentina Fil: Arana, Maria Veronica. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche. Instituto de Investigaciones Forestales y Agropecuarias Bariloche. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; Argentina Fil: Marchelli, Paula. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche. Instituto de Investigaciones Forestales y Agropecuarias Bariloche. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; Argentina

Peripheral sites usually offer suboptimal conditions for species with wide distributions, where expression of phenotypic variability and potential interspecific hybridization might be enhanced. The Patagonian steppe, the largest and southernmost dryland ecosystem in South America, is characterized by natural rangelands dominated by grasses. Festuca pallescens is a keystone species with a wide distribution in Patagonia over diverse environments reaching the extreme arid zones in the Somuncura plateau, a biogeographical island. Our aim is to study the phylogenetic relationships among Festuca pallescens populations as well as between this species and the sympatric F. argentina in North Patagonia. We analysed fourteen populations along a west-east transect of about 500 km in North Patagonia with three types of molecular markers: ITS, chloroplast trnL-F and eight nuclear microsatellites. Bayesian inferences, maximum parsimony and maximum likelihood analyses with trnL-F and ITS showed that F. pallescens is related to the Patagonian clade within the Festuca phylogeny. However, the easternmost populations of F. pallescens at Somuncura plateau were highly differentiated from the other populations and clustered with F. argentina (a sympatric species of the Asian-American clade). Principal coordinates analyses and Bayesian clustering performed with nuclear microsatellites as well as morphoanatomical traits, showed an intermediate position of one of these easternmost populations with respect to the two species, suggesting admixture. The high genetic variability observed in these peripheral populations highlight their relevance for conservation and might be indicating the existence of evolutionary processes triggering events of speciation in the Patagonian fescues. Fil: López, Aldana Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina Fil: Azpilicueta, María Marta. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina Fil: López, Dardo Rubén. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Manfredi. Estación Forestal Villa Dolores; Argentina Fil: Siffredi, G. L.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina Fil: Marchelli, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina

Increasing global aridity combined with changing environmental conditions might cause irreparable alterations in arid and semiarid ecosystems. Knowledge of within-species genetic diversity and adaptive responses, especially along climatic gradients, becomes critical to inform management, conservation and restoration efforts. We combine the analysis of neutral (microsatellites) and adaptive divergence (morphological traits in common garden experiments) between populations along a sharp precipitation gradient in the native Patagonian grass Festuca pallescens, to disentangle patterns of local adaptation and genetic diversity. The identification of genetically based traits under divergent selection denoted the existence of local adaptation in spite of extensive gene flow. Two plant growth patterns were detected associated with two ecological regions. In arid environments, a trade-off between not resigning foliage production, and reducing the exposure to drying agents resulted in a compacted plant architecture; while in dry-sub humid environments, populations exhibited a wide architecture to cope with rainfall and radiation interception. Increasing aridity and grazing might favor a compact plant architecture, and fragmentation might reduce genetic diversity across these environments. Being a widely distributed species, F. pallescens is an excellent model species to study adaptive responses across environmental gradients facing climate change predictions, especially in dryland rangelands that maintain multiple ecosystem functions.

The Patagonian region is characterized by a complex biogeographic history, with evidence of deep phylogeographic breaks shared among species. Of particular interest to conservation is the nature of colonization and settlement patterns after the last glacial period, including the detection of secondary contact between different lineages and/or hybridization among related species around phylogeographic breaks. Here we studied population demography and past hybridization of two widespread tree species endemic to South America, Nothofagus pumilio and N. antarctica.Using 8 nuclear microsatellites we genotyped 41 populations of both species. Genetic variation and structure across the geographic region were evaluated within and among species and the past demographic history of hybridization between the two species was inferred using Approximate Bayesian Computation (ABC).Northern and southern lineages were identified in each species, and Bayesian clustering revealed their convergence at mid latitudes (42°S). Spatial genetic structure (SGS) also indicated the existence of a genetic discontinuity at these latitudes, which is in agreement with previous data from maternal DNA markers. Several populations around 42-44°S presented high levels of genetic diversity with a decrease toward southern populations. Even though the species are clearly differentiated (G'ST=0.335), admixed gene pools were observed in both species. Two independent runs of ABC suggested that inter species admixture-like patterns occurred within the timescale of the Last Glacial Maximum (around 20,000 BP). We also provide evidences of recent and bi-directional hybridization/introgression between the two Nothofagus species and describe features of the populations demography in the past. The settlement of a secondary contact zone in Nothofagus species around 42-44°S coincides with the phylogeographic breaks and hotspots of genetic diversity found in other plant and animal species in Patagonia, highlighting its importance as reservoir of diversity. The characterization of the population history of native species can contribute substantially to long-term conservation and management policies. Fil: Soliani, Carolina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentina Fil: Tsuda, Yoshiaki. Uppsala University; Suecia Fil: Bagnoli, Francesca. Consiglio Nazionale delle Ricerche; Italia Fil: Gallo, Leonardo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina Fil: Vendramin, Giovanni G.. Consiglio Nazionale delle Ricerche; Italia Fil: Marchelli, Paula. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

We investigated the impact of past changes in habitat suitability on the current patterns of genetic diversity of two southern beeches (Nothofagus nervosa and Nothofagus obliqua) in their eastern fragmented range in Patagonian Argentina, and model likely future threats to their population genetic structure. Our goal was to develop a spatially-explicit strategy for guiding conservation and management interventions in light of climate change. We combined suitability modelling under current, past (Last Glacial Maximum ~ 21,000 bp), and future (2050s) climatic conditions with genetic characterization data based on chloroplast DNA, isozymes, and microsatellites. We show the complementary usefulness of the distribution of chloroplast haplotypes and locally common allelic richness calculated from microsatellite data for identifying the locations of putative glacial refugia. Our findings suggest that contemporary hotspots of genetic diversity correspond to convergence zones of different expansion routes, most likely as a consequence of admixture processes. Future suitability predictions suggest that climate change might differentially affect both species. All genetically most diverse populations of N. nervosa and several of N. obliqua are located in areas that may be most severely impacted by climate change, calling for forward-looking conservation interventions. We propose a practical spatially- explicit strategy to target conservation interventions distinguishing priority populations for (1) in situ conservation (hotspots of genetic diversity likely to remain suitable under climate change), (2) ex situ conservation in areas where high genetic diversity overlaps with high likelihood of drastic climate change, (3) vulnerable populations (areas expected to be negatively affected by climate change), and (4) potential expansion areas under climate change. Fil: Marchelli, Paula. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Thomas, E.. Bioversity International; Perú Fil: Azpilicueta, María Marta. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina Fil: Zonneveld, M. van. Bioversity International; Costa Rica Fil: Gallo, L.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina

Habitat fragmentation might significantly affect mating and pollen dispersal patterns in plant populations, contributing to the decline of remnant populations. However, wind-pollinated species are able to disperse pollen at longer distances after opening of the canopy. Our objectives were to characterize the mating system parameters and to estimate the average distance of effective pollen dispersal in the wind- pollinated conifer Austrocedrus chilensis. We sampled 19 "mother trees," 200 progeny, and 81 additional adults (both male and female), in a fragmented population at the Argentinean Patagonian steppe. We registered the spatial po- sitions of individuals and genotyped all samples with five microsatellite markers. We found a high genetic diversity, a moderated rate of biparental inbreeding (tmts=0.105), and a complete absence of correlated paternity (rp=−0.015). The effective number of pollen donors contributing to a single mother (Nep) was 13.9. Applying TWOGENER,weestimated a low but significant differentiation among the inferred pollen pools (ΦFT=0.036,p=0.001) and a very large average pollen dispersal distance (d=1,032.3 m). The leptokurtic distribution (b=0.18) presumes a potential for even larger dispersal dis- tances. The high genetic diversity, the mating patterns, and the extensive pollen dispersal presume that habitat fragmentation did not have a negative impact on pollen movement in this population of A. chilensis. Genetic connectivity among fragmented populations scattered in the Patagonian region is possible, and we stress the need of management policies at the landscape level.

Development of appropriate forest conservation and management measures for a given tree species includes the identification of distinct genetically homogeneous units across its overall distribution range, which depends on the availability of knowledge on genetic, morphological and adaptive variation. This has important implications for germplasm transfer within and between areas, for example in reforestation or restoration activities. Genetic zones are defined as genetically more or less homogeneous regions within which propagation material can be transferred with relative certainty not to cause changes at the genetic structure level. The main goal of this study was to define genetic zones for Nothofagus nervosa and Nothofagus obliqua within their Argentinean natural distribution range. A total of 823 individuals belonging to 24 populations (14 of N. nervosa and 10 of N. obliqua, μ= 34 ± 5) were genotyped by means of seven nuclear microsatellite markers. The geographic clustering encountered through the application of a Bayesian approach was analysed in combination with additional information on diversity parameters, chloroplast DNA and isozymes. For assembling the maps showing the distribution of clusters, we averaged cluster membership values of trees in each grid cell. This allowed us to distinguish five genetic zones for N. nervosa and three for N. nervosa. The identified genetic zones were consistent with the management history of the species, and display a certain level of geographic congruence. To visualize geographical patterns in nSRR richness and the distribution of different clusters of both species, we carried out grid-based spatial analyses using 30 seconds grid cells (~1 km at the equator) as the unit of analyses. We observed higher allelic richness values in the surroundings of areas identified as potential glacial refuges, which suggest that the distribution pattern of allelic richness is closely associated with the glacial history of the species within the region. We expect this information to constitute a valuable tool for the identification of seed transfer zones, and to guide recruitment and plantation activities in the context of domestication programs of both species in Argentina. For migration assisted programs under progressive climate change the identification of these zones together with knowledge concerning hotspots at genetic diversity level should constitute an input for planning the activities. Fil: Azpilicueta, María Marta. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina Fil: Gallo, L. A.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina Fil: van Zonneveld, M.. Bioversity International. Regional Office for the Americas; Colombia Fil: Thomas, E.. Bioversity International. Regional Office for the Americas; Colombia Fil: Moreno, Angela Carolina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Marchelli, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina

The mating system (outcrossing, selfing, and biparental inbreeding) and the extent of pollen flow are two of the most important genetic features that determine the genetic structure of plant populations, and both are crucial for the design of conservation strategies. The objectives here were to estimate mating system parameters and to fit the pollen dispersal kernel for the southern beech, Nothofagus nervosa. We sampled 25 mothers and 372 progeny from two stands in the Tromen Lake region of Argentina. We registered spatial positions of the maternal trees, and genotyped mothers and offspring for five simple sequence repeat markers.

In phylogenetically related plant species, hybridization can influence their current genetic structure. Long-lasting hybridization may be related to persistence in shared glacial refugia, where the differential abilities of each species to survive could have provided adaptations to changing environmental conditions. In temperate South American forests at the Patagonia region, the pattern of Quaternary glaciations offered several opportunities for refuge. At mid-latitudes (42° to 44° S), particular topographic characteristics determined different glaciation patterns, defining the existence of a transitional zone. We studied two widespread Nothofagus species (Nothofagus pumilio, Nothofagus antarctica) characterized by contrasting plasticity. We screened 40 coupled populations with three cpDNA markers and found 14 different haplotypes. Both species presented significant phylogeographic structure (N ST ≥ G ST, p > 0.001), with two geographically segregated lineages (north–south). A latitudinal cline in the distribution of genetic diversity was determined, with most variable populations in the north (35°–41° S). Population diversity diminished to southern latitudes, but a particular situation occurs between 42°S and 44°S. The transition zone, a putative refuge area, presented unique haplotypes. The more plastic species, N. antarctica, probably persisted in more refuge areas, which could be reflected in its higher levels of diversity. In these species, sympatric distribution explains introgression (IG > IG e), but the differential levels of haplotype sharing between N. pumilio and N. antarctica at population level are relevant to the understanding of phylogeographic patterns. Hybridization may have facilitated recruitment in the onset of postglacial colonization by middle to long-distance pollen dispersal. In the current scenario of climate change, the presence of hybrids with different plastic responses is of remarkable importance.

Fragmentation of the habitat due to glaciations, fires and human activities affected the distribution range of Araucaria araucana in southern South America. On the borders of the Argentinean Patagonian steppe, the species is restricted to isolated patches without natural regeneration. Our objective is to test the hypothesis that these populations are relicts of pre-Pleistocene origin. A total of 224 individuals from 16 populations were sampled. Twenty chloroplast microsatellites, 19 non-coding chloroplast DNA regions and eight mitochondrial DNA fragments were screened for polymorphisms. A low transferability rate of universal primers from Pinaceae and also a low variation were detected for this ancient species. Only one non-coding region of the chloroplast DNA showed polymorphism allowing the identification of five haplotypes. A low genetic differentiation (G ST = 0.11; G′ ST = 0.267) and lack of geographic structure was found. Allelic richness was lower and genetic differentiation higher among the eastern isolated populations, suggesting a long lasting persistence. Conservation guidelines are given for these relictual populations, which are located outside the limits of the National Parks.

Climatic oscillations during the Quaternary strongly affected the distribution of warm-temperate tree species, which experienced local restrictions into ice-free areas and posterior expansions. To evaluate the impact of these range movements on the genetic structure of populations, we performed a phylogeographical analysis of the species Nothofagus obliqua with chloroplast DNA markers. A total of 27 populations covering the whole natural distribution range were analyzed using polymerase chain reaction-restriction fragment length polymorphism. Diversity (h T, h S), allelic richness (r g), and differentiation among populations for unordered (G ST) and ordered alleles (N ST) were calculated. The relationships among haplotypes were evaluated by the construction of a minimum spanning network. The spatial distribution of the genetic variation was analyzed through a Mantel test and with a nested analysis of molecular variance to differentiate between geographic regions. The screening of 11 non-coding regions allowed the identification of 14 haplotypes. A high genetic differentiation was detected (N ST = 0.875 and G ST = 0.824) with the existence of phylogeographic structure (p

Nothofagus is the main component of southern South American temperate forests. Overexploitation in the past has led to the loss of 40% of the original distribution range. Genetic diversity as well as biological processes shaping the distribution of the genetic variation (e.g. gene flow) constitutes basic knowledge for the implementation of conservation measures and for the definition of Evolutionary Significant Units. Nuclear microsatellites are the marker of choice for gene flow and fine-scale genetic structure studies. We enlarged a previous set of microsatellites (SSRs) for South American Nothofagus species, with special concern to Nothofagus nervosa (Phil.) Dim. et Mil. Five new SSRs are presented with allele numbers up to 12 in a single population. The primers transferred well to five related species (N. obliqua (Mirb.) Oerst, N. glauca (Phil.) Krasser, N. dombeyi (Mirb.) Oerst , N. pumilio (Poepp et Endl.) Krasser and N. antarctica (G. Forster) Oerst, with allele numbers up to 11. The high level of polymorphism promises a sufficient power for gene flow and parentage analyses.

During the Quaternary, southern South American temperate forests were confined to small and isolated refugia. Recolonization could be related not only with location of refugia but also with postglacial phenomena like volcanism, which could have interrupted the expansion of the forests. The aim of this study was to analyze the local effect of volcanism during the postglacial migration of Nothofagus nervosa in a particular region of Argentina were convergence of two migratory routes was suggested. The main question is whether admixture occurred or not and if the current populations are connected by pollen or seed gene flow. Two populations separated by a 3-km-width lava flow were sampled. Buds from 30 individuals of each of the two populations and from a total of 142 juveniles were analyzed. Genetic variation was detected through maternally inherited chloroplast deoxyribonucleic acid (cpDNA; polymerase chain reaction restriction fragment length polymorphisms of two fragments) and nuclear markers like isozymes (six loci) and simple sequence repeats (three loci). Population genetic parameters were estimated and the existence of a genetic structure was tested with an analysis of molecular variance. Historical gene flow was estimated through the indirect method of the genetic differentiation (F ST). Chloroplast DNA revealed a total genetic differentiation between the two populations indicating completely isolation respecting seed gene flow. On the contrary, the degree of genetic differentiation for the nuclear markers was significantly lower, and moderate levels of historical gene flow through pollen were inferred. The results suggest that in this area, volcanism has played an important local role during the expansion of N. nervosa maintaining these two populations separated.

Aim The distribution of the genetic variation in long-lived species is a combination of both, historical and current processes. In Nothofagus nervosa (Phil.) Dim. et Mil., the possible existence of multiple glacial refugia, the unidirectional gene flow along fragmented areas and the natural hybridization with the related species Nothofagus obliqua (Mirb.) Oerst. highlights as the most important factors responsible for modelling its genetic structure. The present study aims to find out the relative importance of these evolutionary processes in determining the distribution pattern of the genetic variation in N. nervosa. Location The study was carried out in north-western Patagonia, Argentina. Twenty populations covering the entire distribution range of N. nervosa in Argentina were analysed. For comparison purposes, three populations from Chile were also included. Methods Genetic variation was detected using isozyme gene markers; diversity and differentiation parameters were calculated. A cluster analysis was performed and the correlation between genetic and geographical distances was tested. Results Levels of genetic variation were relatively high given the small distribution range of the species in Argentina. Genetic and geographical distances were not correlated and a longitudinal trend in the genetic variation was evident. Hotspots of diversity with rare and private alleles were observed among western populations, while hybrid seeds were found almost exclusively among eastern populations. Main conclusions The higher level of diversity observed in western populations could be related with the location of glacial refugia. Furthermore, it should also reflect low levels of gene flow given the eastward unidirectional winds. On the contrary, ancient and current interspecific hybridization processes would mainly cause the particular genetic constitution of the eastern populations. Evidence is presented supporting that glaciations and hybridization were the main factors shaping the distribution of the genetic variation in N. nervosa.

Diversity and differentiation among 11 Argentine populations of the South American southern beech, Nothofagus nervosa (Phil.) DimitriMilano, were studied using eight isozyme gene markers. Genetic diversity, observed heterozygosity, mean number of alleles per locus, Gregorius' genetic distance, amount of genetic differentiation and mean level of differentiation among populations were estimated. Introgression of N. obliqua into the gene pool of N. nervosa was analysed using two species-specific isozyme gene markers (Adh-A and Pgi-B). As in most forest tree species, the main genetic variation was found within populations. Mean observed heterozygosity for the species was 17.3%, whilst mean level of genetic differentiation (deltage) was 4.6%. The most differentiated locus was Mdh-B with differences in 10% of the effective number of genes. From the analysis of the species distribution pattern it is suggested that genetic variation is geographically structured through the different lake watersheds along which the species is distributed. The occurrence of natural interspecific hybridization in some of the watersheds, together with the unidirectional gene flow along these watersheds sharpens this latitudinal structure. Different evolutionary stages in the introgressive hybridization process are apparently taking place in different lake watersheds.

Nothofagus nervosa (=N. alpina) is one of the most important native forest tree species of Argentina, with a very small natural distribution area, fast growth and a high wood quality. Its overexploitation in the past seriously affected some populations and made others disappear, making it necessary to implement conservation policies and breeding programs. In order to study the genetic and geographic variation of the species, seeds from a total of 29 populations from the entire natural distribution area in Argentina were harvested, 11 of them during four consecutive years. Annual and geographic covariation of seed production, seed weight and proportion of seeds damaged by insects were analyzed. Significant differences among populations and among years for all studied traits were found. Seed production was highly variable, both among populations and among years. `Partial mast years' seem to occur every two years, whereas the occurrence of `full mast years' has a lower frequency. A significant population × year interaction was found both for the proportion of damaged seeds and for the seed weight. The proportion of seeds damaged by insects was very important, reaching >80% of the total seed produced in some populations. The differences in the quantity of attacked seeds among years are discussed in relation to seed production, insect's life cycle and climatic factors. Seed weight was also variable among populations and years, despite the small natural distribution area of the species in Argentina. Best seed quality, according to lower proportion of damaged seeds and higher seed weight, was observed in the analyzed `full mast year'. This would also imply a better genetic representation of populations with seed samples harvested during these years. A lower proportion of damaged seeds as well as the heaviest seeds were also found among those seeds fallen during the first part of the seed-fall period. The found covariation is discussed in relation to patterns of genetic variation previously found in this species and to the implementation of genetic studies and conservation and breeding programs.

An enriched genomic library was constructed and 9 novel polymorphic tetranucleotide microsatellite markers developed for Austrocedrus chilensis, the most economically important native conifer in the Andean Patagonian region. Polymorphism was investigated for these markers in 48 individuals from two populations. Numbers of alleles ranged from 3 to 19 and levels of observed heterozygosity among the 9 loci ranged from 0.32 to 0.95. No locus combinations exhibited linkage disequilibrium. These polymorphic markers will be useful tools for the study of demography and gene flow and more in general for population and conservation genetics of this species.

Nothofagus nervosa is one of the most important species of the temperate forests of southern South America. On the eastern slope of the Andes Mountains (Argentina) it has a very small and narrow natural distribution area which follows the valleys of the numerous west-east lake basins. Re-colonisation after the last glaciation is assumed to have originated from refugia located in the western pacific coast or even in free interglacial patches of the Andes Mountains. Sixteen pairs of primers were used to amplify 16 non-coding regions of chloroplast DNA in 11 populations from over the entire distribution area in Argentina. After restriction analysis two polymorphic fragments were found which defined two haplotypes and allowed a differentiation among populations. A clear geographic divide occurs separating populations distributed south and north of a west-east mountain chain. This suggests that after the last glaciation the species spread out from at least two different refugia. Hypotheses about the possible location of these refugia are discussed.

Background: Austrocedrus chilensis (D. Don) Pic. Ser. et Bizzarri commonly known as Patagonian cypress is a member of the Cupressaceae family, characterized by a high adaptive potential for growing in marginal areas and good timber quality. The species grows over a wide area and under a wide range of rainfall. This study assessed adaptive genetic variation at SNP level in candidate genes involved in response to drought stress. Results: A total of 18 single nucleotide polymorphisms (SNPs) were found among 1,428 bp. Average nucleotide diversity value (π = 0.00312) was similar to those previously reported in other Cupressaceae. The Fst average among genes and populations was 0.163 and the lowest differentiation was observed in continuous and humid populations. A number of neutrality tests were applied to find evidence of positive selection in our candidate gene set, but only AcAQP2 gene in Pedregoso and San Ramón populations revealed significant departures from neutrality with positive values suggesting balancing selection. Conclusions: In this study we report the levels of nucleotide diversity searched in some drought stress candidate genes in Austrocedrus chilensis and the selective factors that may be acting on this species. Fil: Pomponio, Maria Florencia. Instituto Nacional de Tecnologia Agropecuaria. Centro Nacional de Inv. Agropecuarias. Centro de Invest.de Recursos Naturales. Instituto de Recursos Biologicos; Argentina Fil: Torales, Susana. Instituto Nacional de Tecnologia Agropecuaria. Centro Nacional de Inv. Agropecuarias. Centro de Invest.de Recursos Naturales. Instituto de Recursos Biologicos; Argentina Fil: Gallo, Leonardo. Instituto Nacional de Tecnologia Agropecuaria. Centro Reg.patagonia Norte. Estacion Exptal.agrop.s.c.de Bariloche. Grupo de Genetica Forestal; Argentina Fil: Pastorino, Mario Juan. Instituto Nacional de Tecnologia Agropecuaria. Centro Reg.patagonia Norte. Estacion Exptal.agrop.s.c.de Bariloche. Grupo de Genetica Forestal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Marchelli, Paula. Instituto Nacional de Tecnologia Agropecuaria. Centro Reg.patagonia Norte. Estacion Exptal.agrop.s.c.de Bariloche. Grupo de Genetica Forestal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Cervera, María Teresa. Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria. Centro de Investigación Forestal; España Fil: Marcucci Poltri, Susana Noemí. Instituto Nacional de Tecnologia Agropecuaria. Centro Nacional de Inv. Agropecuarias. Centro de Invest.de Cs.veterinarias y Agronomicas. Instituto de Biotecnologia; Argentina

An enriched genomic library was constructed and 9 novel polymorphic tetranucleotide microsatellite markers developed for Austrocedrus chilensis, the most economically important native conifer in the Andean Patagonian region. Polymorphism was investigated for these markers in 48 individuals from two populations. Numbers of alleles ranged from 3 to 19 and levels of observed heterozygosity among the 9 loci ranged from 0.32 to 0.95. No locus combinations exhibited linkage disequilibrium. These polymorphic markers will be useful tools for the study of demography and gene flow and more in general for population and conservation genetics of this species.

Researchers dealing with conservation subjects usually do not put the results of their work into practice, even when the primary purpose of their research is the preservation of biodiversity. In the South American temperate forests we identified an area with the highest genetic diversity in Argentina of Nothofagus nervosa, one of the most relevant southern beech species. Based on the information of our scientific study and our recommendations, the authorities of Lanin National Park changed the protection status of this area to avoid logging. The new forestry management plans include consideration of “high genetic diversity” in decisions on where logging will be allowed. Results of our initial genetic study induced the analysis of biodiversity at the species and ecosystems levels, which yielded results similar to our genetic studies. A strong connection among researchers and managers from the onset of our study and the awareness of the former about the importance of the implementation of the research work were key to bridging the gap between conservation research and conservation practice. Resumen: Los investigadores que abordan temas de conservacion usualmente no ponen en practica los resultados de su trabajo, aun cuando la preservacion de la biodiversidad es el proposito primario de su investigacion. En los bosques templados de America del Sur identificamos un area con la mayor diversidad genetica en Argentina de Notophagus nervosa, una de las especies de hayas surenas mas relevante. Con base en la informacion de nuestro estudio cientifico y nuestras recomendaciones, las autoridades del Parque Nacional Lanin cambiaron el estatus de proteccion de esta area para evitar la tala. Los nuevos planes de manejo forestal incluyen la consideracion de “alta diversidad genetica” en decisiones que implican la autorizacion de tala. Los resultados de nuestro estudio genetico inicial indujeron el analisis de biodiversidad a nivel de especies y de ecosistema, que produjo resultados similares a los de nuestros estudios geneticos. Una conexion estrecha entre los investigadores y los manejadores desde el inicio de nuestro estudio y el convencimiento de los primeros sobre la importancia de la implementacion del trabajo de investigacion fueron claves para tender puentes entre la investigacion en conservacion y la practica de la conservacion.

Knowledge about current patterns of genetic structure of populations together with the evolutionary history of a species helps to understand and predict the adaptation of populations to future climate change. We assayed variation at nuclear microsatellite markers among peripheral vs. continuous populations of the temperate South American species Austrocedrus chilensis, to investigate the role of historical vs. demographical forces in shaping population genetic structure. This species occurs in continuous populations in the west and central distribution range, but becomes highly fragmented at the eastern limit, which comprised ice-free areas during Quaternary glaciations and has extreme climatic conditions at present times. Bayesian analysis methods identified two contrasting patterns of genetic structure; (I) populations from humid, mesic and peri-glacial regions formed a single deme with relatively low genetic differentiation and high admixture levels whereas (II) a highly heterogeneous genetic structure with low level of admixture was found in the steppe, towards the east and northeast limit of the distribution range. In the steppe, population fragmentation, restricted gene flow and isolation-by-distance were also inferred. In addition, several small steppe populations showed high genetic diversity and divergent gene pools, suggesting that they constitute ancient refuges from pre-Holocene glaciations with just a subgroup of them contributing significantly to post-glacial spread. These results are discussed in relation to patterns of genetic variation found for other temperate species and the contribution of the particular southern Andes topography and climate to post-glacial spread.

Different regional patterns of glaciation are expected to have brought about a differential effect on the present genetic structure of natural tree populations in the temperate regions. The aim of the present study is to test this hypothesis in Nothofagus antarctica, a key tree species of the temperate forests of southern South America. An almost continuous ice layer characterized the region of the Andes south of 41 degrees S, while towards northern latitudes the pattern was more fragmented. Therefore, a higher chance for the location of larger or more numerous glacial refuges in the north of the Argentinean range, leads us to predict a higher genetic diversity in this region. Twelve natural populations of N. antarctica were sampled along the northern half of its Argentinean range, including six above 41 degrees S and six below that latitude. Sampled populations were genetically characterized through cpDNA and isozyme gene markers. Both groups of populations were compared by means of several diversity and differentiation parameters. A genetic structure analysis was conducted with isozyme data through clustering and Bayesian approaches. Based on three polymorphic chloroplast regions, only two haplotypes were distinguished, one corresponding to the nine northernmost sampled populations and the other to the two southernmost ones. Only the population located between those two groups resulted polymorphic. AMOVA analyses also revealed a latitudinal genetic structure for the populations surveyed, and higher levels of genetic variation were recognized in the northern populations.

En trabajos de investigacion en genetica de poblaciones y evolutiva asi como en el desarrollo tecnologico de los programas de mejora, la evaluacion correcta de la variacion genetica es el punto crucial para la conclusion acertada y la toma de decisiones. El uso de marcadores geneticos bioquimicos y moleculares en especies forestales permitio un salto cualitativo en la confiabilidad de la informacion sobre la variacion genetica y la resolucion en forma contundente de problemas de importancia practica tanto en genetica poblacional como en programas de mejora. En especies del genero Nothofagus este tipo de marcadores comenzo a utilizarse hace aproximadamente 20 anos, aunque en especies nativas de los bosques templados de Sudamerica la primera referencia data de diez anos atras. El presente trabajo describe los aportes que la genetica molecular ha hecho hasta la fecha en los estudios de variacion genetica del genero Nothofagus en general y de Nothofagus nervosa (rauli) y N. obliqua (roble, roble pellin) en particular.

Water-use efficiency (WUE) is a physiological parameter that plays a significant role in the evolutionary dynamics of many forest tree species. It can be estimated indirectly through carbon isotope discrimination (Δ). In general, plants of more arid origins have lower values of Δ. In order to study the degree of genetic control of this parameter and the genetic variation in Δ of Patagonian Cypress seedlings, three Argentinean natural populations chosen to represent two contrasting precipitation regimes were sampled in a common garden trial. The dry situation was represented by two neighboring marginal forest patches from the steppe, while the humid condition was represented by a population with 1,200 mm higher mean annual precipitation. Height (H) and Δ were measured in 246 five-year-old seedlings from 41 open-pollinated families. The factor ‘family’ had a significant effect on both variables; however heritability for Δ was found not to be significant in two out of the three populations. This could be explained by low sample size in one of them and by a real evolutionary effect in the other. An inverse association between H and Δ was verified, which is interpreted as evidence of an adaptation process at the intra-population level. The studied populations were not shown to discriminate carbon isotopes differently; hence evidence of adaptation to current environmental conditions could not be obtained. On the other hand, the arid populations proved to be quite different in terms of genetic variation, which seems to be the consequence of genetic drift and isolation.

Nothofagus nervosa is one of the most emblematic native tree species of Patagonian temperate forests. Here, the shotgun RNA-sequencing (RNA-Seq) of the transcriptome of N. nervosa, including de novo assembly, functional annotation, and in silico discovery of potential molecular markers to support population and associations genetic studies, are described. Fil: Torales, Susana Leonor. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; Argentina Fil: Rivarola, Maximo Lisandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Pomponio, Maria Florencia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; Argentina Fil: Fernandez, Paula Del Carmen. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Acuña, Cintia Vanesa. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentina Fil: Marchelli, Paula Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Argentina Fil: Gonzalez, Sergio Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentina Fil: Azpilicueta, María M. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Argentina Fil: Hopp, Horacio Esteban. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina Fil: Gallo, Leonardo A. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Argentina Fil: Paniego, Norma Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Marcucci Poltri, Susana Noemi. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentina

Cross-species amplification of microsatellites is a common procedure to obtain suitable markers to be used in population genetic studies. Primers designed for one (source) species are used to amplify homologous loci in related (target) species. It is expected that phylogenetically close species will share a higher proportion of markers, and genetic distance could be a useful parameter to predict successful transferability between different taxonomic groups. We analyzed twenty-two primer pairs developed for Araucaria angustifolia (Bertol.) Kuntze in five target species of the Araucariaceae family. The results were summarized in vectors of presence and absence of bands and compared through the Jaccard similarity index. Using the sequences of eight published genes, genetic distances between pairs of species were estimated and related to transferability rate using Pearson correlations. Successful transfer rate ranged from 31.8 to 77.3%, being these among the highest reported for plants. The highest transfer rate was observed between the South American species. The transferability was confirmed sequencing seven fragments amplified in A. araucana (Molina) K. Koch, and using the best five to estimate genetic diversity parameters in a natural population of this Andean coniferous. Key word: cross species amplification; pairwise genetic distance; conservation of microsatellite loci; Pehuen.