Transferibilidad cruzada de microsatélites a cinco especies de Araucariaceae: una herramienta útil para estudios de genética de poblaciones en Araucaria araucana

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.La transferencia de cebadores que amplifican loci microsatélites desde otras especies es una práctica habitual para obtener marcadores adecuados para estudios de genética poblacional. Los cebadores diseñados en una especie (fuente) son utilizados para amplificar loci homólogos en especies relacionadas (blanco). Se espera que especies cercanas filogenéticamente compartan un mayor número de marcadores y la distancia genética entre especies podría ser un parámetro útil para predecir el éxito de la transferencia entre diferentes grupos taxonómicos. Se analizó la transferencia de veintidós primers, desarrollados para Araucaria angustifolia (Bertol.) Kuntze, a cinco especies blanco de la familia Araucariaceae. Los resultados se resumieron en vectores de presencia y ausencia de bandas y fueron comparados a través del índice de similitud de Jaccard. Se estimaron las distancias genéticas de a pares entre las especies analizadas utilizando las secuencias de ocho genes, y se las relacionó con el índice de transferencia utilizando correlaciones de Pearson. El éxito de la transferencia varió entre 31.8 y 77.3%, encontrándose estos valores entre los más altos reportados en plantas. El mayor índice de transferencia se verificó entre las especies sudamericanas. La transferencia fue confirmada secuenciando siete fragmentos amplificados en Araucaria araucana (Molina) K. Koch, y utilizando los cinco mejores para estimar parámetros de diversidad genética en una población natural de esta conífera andina

Genetic diversity and divergence at the Arbutus unedo L. (Ericaceae) westernmost distribution limit

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

Towards the dynamic conservation of Serbian spruce (Picea omorika) western populations

Key message High levels of genetic diversity, pronounced genetic structure and limitations to gene flow in Serbian spruce, a rare and endangered tree species from the refugial Balkan region, point towards a "one population-one unit" strategy for assembling a network of Genetic Conservation Units (GCUs) for its dynamic conservation. On the other hand, genetic information also permits to prioritize populations for conservation based on their contribution to genetic diversity and differentiation. Context Serbian spruce, Picea omorika (Panc.) Purk., is a rare, IUCN red-listed European conifer endemic to the Balkan region. Its current rigid conservation (without any intervention allowed in similar to 30 remnant populations) and the extant network of Genetic Conservation Units (four natural populations and three planted stands from the western part of the species range, in the Republic of Srpska, Bosnia and Herzegovina, RS-BH) might be ineffective in preserving the species' genetic diversity. Aims To facilitate implementation of dynamic conservation of Serbian spruce by re-assessing the number and size of remnant populations in RS-BH and updating genetic knowledge on these understudied western Serbian spruce populations. Methods Comprehensive field survey in RS-BH, genotyping 689 individuals from 14 western populations with ten highly informative nuclear EST-SSRs and analytical methods for prioritizing populations for conservation based on their contribution to the geographical structuring of genetic diversity. Results The genetic diversity of western Serbian spruce populations (Ae = 2.524, H-E = 0.451) is comparable with what was found for eastern ones; they are highly genetically differentiated (Hedrick's G'(ST) = 0.186; Jost's D = 0.097) and comprise ten distinct gene pools. Effective population size is often gt = 15. As much as 14% of alleles is not preserved in the extant GCUs established in natural populations. Eight populations positively contribute to within-population genetic diversity, four to genetic differentiation, and two are globally important in terms of diversity and differentiation. Although wildfires may contribute to admixture of different gene pools, re-establishment from seeds from extirpated populations has likely prevailed in studied populations. Conclusions A larger network of GCUs is required for the dynamic conservation of western Serbian spruce populations. A "one population-one unit" strategy, with 14 GCUs, would represent the safest approach to conserve species extant genetic variation in this part of the species range. Nonetheless, a strategy to prioritize populations for conservation based on their contribution to allelic diversity has been put forward. Given the rapid global warming and peculiarities of Serbian spruce distribution, habitat and life history traits, conservation measures based on a rigorously designed GCU network are urgent for its rescue and survival

Dynamic conservation and utilization of forest tree genetic resources: indicators for in situ and ex situ genetic conservation and forest reproductive material

A set of Criteria and Indicators (C&I) for sustainable forest management was adopted by the Forest Europe process as a tool to aid forest policy formulation and decision making, forest monitoring and communication. Six criteria reflect complementary aspects of sustainable forest management in the pan-European region. These are currently being assessed (2019) by a set of 34 quantitative and 11 qualitative indicators. Indicator 4.6 is a quantitative indicator which contributes to Criterion 4 (Maintenance, conservation and appropriate enhancement of biological diversity in forest ecosystems) by focusing on the conservation and use of genetic resources. Between 2016 and 2019 the indicator was revised by a working group established by the EUFORGEN Programme, with the aim of addressing a number of shortcomings in the existing system. The report, Revised indicator on genetic resources (4.6) of the pan-European criteria and indicators for sustainable forest management, addresses the reasoning behind the revision of the indicator and provides details regarding its composition and the reporting of conservation efforts linked to each of the sub-indicators. The revised indicator comprises four sub-indicators: 1. Dynamic conservation (in situ and ex situ) of native species populations; 2. Dynamic conservation (ex situ) of populations of non-native species; 3. Static ex situ conservation; 4. Forest reproductive material production; resulting in informative and comparable verifiers and therefore an improvement in its overall reliability, robustness and resolution. Temporal monitoring of progress made can be carried out using EUFORGEN’s synthetic radar chart representation. I n d i c a t o r o n G e n e t i c R e s o u r c e s xii To ensure the effective use of the revised indicator, the working group gives a number of recommendations: • EUFORGEN member countries should continue to implement and further develop the Pan-European strategy for genetic conservation of forest trees. • Through the EUFORGEN Programme, member countries should work together to develop an agreed set of “minimum requirements” for static ex situ conservation. • Countries should support the development of the national lists of native tree species occurring in each country. With over twenty years of experience in FGR conservation and ten years in managing the EUFGIS information system on in situ conservation units of FGR in Europe, EUFORGEN can guarantee the reliability, specificity, relevance and usefulness of the revised indicator and sub-indicators, which come with a set of more precise definitions and standard scales.202

Functional Relationships of Wood Anatomical Traits in Norway Spruce

The quantitative assessment of wood anatomical traits offers important insights into those factors that shape tree growth. While it is known that conduit diameter, cell wall thickness, and wood density vary substantially between and within species, the interconnection between wood anatomical traits, tree-ring width, tree height and age, as well as environment effects on wood anatomy remain unclear. Here, we measure and derived 65 wood anatomical traits in cross-sections of the five outermost tree rings (2008–2012) of 30 Norway spruce [Picea abies (L.) H. Karst.] trees growing along an altitudinal gradient (1,400–1,750 m a.s.l.) in the northern Apennines (Italy). We assess the relationship among each anatomical trait and between anatomical trait groups according to their function for (i) tree-ring growth, (ii) cell growth, (iii) hydraulic traits, and (iv) mechanical traits. The results show that tree height significantly affects wood hydraulic traits, as well as number and tangential diameter of tracheids, and ultimately the total ring width. Moreover, the amount of earlywood and latewood percentage influence wood hydraulic safety and efficiency, as well as mechanical traits. Mechanically relevant wood anatomical traits are mainly influenced by tree age, not necessarily correlated with tree height. An additional level of complexity is also indicated by some anatomical traits, such as latewood lumen diameter and the cell wall reinforcement index, showing large inter-annual variation as a proxy of phenotypic plasticity. This study unravels the complex interconnection of tree-ring tracheid structure and identifies anatomical traits showing a large inter-individual variation and a strong interannual coherency. Knowing and quantifying anatomical variation in cells of plant stem is crucial in ecological and biological studies for an appropriate interpretation of abiotic drivers of wood formation often related to tree height and/or tree age

Marginality indices for biodiversity conservation in forest trees

Marginal and peripheral populations are important for biodiversity conservation. Their original situation in a species’ geographic and ecological space often confers them genetic diversity and traits of high adaptive value. Yet theoretical hypotheses related to marginality are difficult to test because of confounding factors that influence marginality, namely environment, geography, and history. There is an urgent need to develop metrics to disentangle these confounding factors. We designed nine quantitative indices of marginality and peripherality that define where margins lie within species distributions, from a geographical, an environmental and a historical perspective. Using the distribution maps of eight European forest tree species, we assessed whether these indices were idiosyncratic or whether they conveyed redundant information. Using a database on marginal and peripheral populations based on expert knowledge, we assessed the capacity of the indices to predict the marginality status of a population. There was no consistent pattern of correlation between indices across species, confirming that the indices conveyed different information related to the specific geometry of the species distributions. Contrasting with this heterogeneity of correlation patterns across species, the relative importance of the indices to predict the marginality status of populations was consistent across species. However, there was still a significant country effect in the marginality status, showing a variation in expert opinion of marginality vis-á-vis the species distribution. The marginality indices that we developed are entirely based on distribution maps and can be used for any species. They pave the way for testing hypotheses related to marginality and peripherality, with important implications in quantitative ecology, genetics, and biodiversity conservation

Baseline risk factors of in-hospital mortality after surgery for acute type A aortic dissection: an ERTAAD study

Background Surgery for type A aortic dissection (TAAD) is associated with high risk of mortality. Current risk scoring methods have a limited predictive accuracy.Methods Subjects were patients who underwent surgery for acute TAAD at 18 European centers of cardiac surgery from the European Registry of Type A Aortic Dissection (ERTAAD).Results Out of 3,902 patients included in the ERTAAD, 2,477 fulfilled the inclusion criteria. In the validation dataset (2,229 patients), the rate of in-hospital mortality was 18.4%. The rate of composite outcome (in-hospital death, stroke/global ischemia, dialysis, and/or acute heart failure) was 41.2%, and 10-year mortality rate was 47.0%. Logistic regression identified the following patient-related variables associated with an increased risk of in-hospital mortality [area under the curve (AUC), 0.755, 95% confidence interval (CI), 0.729-0.780; Brier score 0.128]: age; estimated glomerular filtration rate; arterial lactate; iatrogenic dissection; left ventricular ejection fraction <= 50%; invasive mechanical ventilation; cardiopulmonary resuscitation immediately before surgery; and cerebral, mesenteric, and peripheral malperfusion. The estimated risk score was associated with an increased risk of composite outcome (AUC, 0.689, 95% CI, 0.667-0.711) and of late mortality [hazard ratio (HR), 1.035, 95% CI, 1.031-1.038; Harrell's C 0.702; Somer's D 0.403]. In the validation dataset (248 patients), the in-hospital mortality rate was 16.1%, the composite outcome rate was 41.5%, and the 10-year mortality rate was 49.1%. The estimated risk score was predictive of in-hospital mortality (AUC, 0.703, 95% CI, 0.613-0.793; Brier score 0.121; slope 0.905) and of composite outcome (AUC, 0.682, 95% CI, 0.614-0.749). The estimated risk score was predictive of late mortality (HR, 1.035, 95% CI, 1.031-1.038; Harrell's C 0.702; Somer's D 0.403), also when hospital deaths were excluded from the analysis (HR, 1.024, 95% CI, 1.018-1.031; Harrell's C 0.630; Somer's D 0.261).Conclusions The present analysis identified several baseline clinical risk factors, along with preoperative estimated glomerular filtration rate and arterial lactate, which are predictive of in-hospital mortality and major postoperative adverse events after surgical repair of acute TAAD. These risk factors may be valuable components for risk adjustment in the evaluation of surgical and anesthesiological strategies aiming to improve the results of surgery for TAAD.Clinical Trial Registration https://clinicaltrials.gov, identifier NCT04831073

Outcome after Surgery for Iatrogenic Acute Type A Aortic Dissection

(1) Background: Acute Stanford type A aortic dissection (TAAD) may complicate the outcome of cardiovascular procedures. Data on the outcome after surgery for iatrogenic acute TAAD is scarce. (2) Methods: The European Registry of Type A Aortic Dissection (ERTAAD) is a multicenter, retrospective study including patients who underwent surgery for acute TAAD at 18 hospitals from eight European countries. The primary outcomes were in-hospital mortality and 5-year mortality. Twenty-seven secondary outcomes were evaluated. (3) Results: Out of 3902 consecutive patients who underwent surgery for acute TAAD, 103 (2.6%) had iatrogenic TAAD. Cardiac surgery (37.8%) and percutaneous coronary intervention (36.9%) were the most frequent causes leading to iatrogenic TAAD, followed by diagnostic coronary angiography (13.6%), transcatheter aortic valve replacement (10.7%) and peripheral endovascular procedure (1.0%). In hospital mortality was 20.5% after cardiac surgery, 31.6% after percutaneous coronary intervention, 42.9% after diagnostic coronary angiography, 45.5% after transcatheter aortic valve replacement and nihil after peripheral endovascular procedure (p = 0.092), with similar 5-year mortality between different subgroups of iatrogenic TAAD (p = 0.710). Among 102 propensity score matched pairs, in-hospital mortality was significantly higher among patients with iatrogenic TAAD (30.4% vs. 15.7%, p = 0.013) compared to those with spontaneous TAAD. This finding was likely related to higher risk of postoperative heart failure (35.3% vs. 10.8%, p < 0.0001) among iatrogenic TAAD patients. Five-year mortality was comparable between patients with iatrogenic and spontaneous TAAD (46.2% vs. 39.4%, p = 0.163). (4) Conclusions: Iatrogenic origin of acute TAAD is quite uncommon but carries a significantly increased risk of in-hospital mortality compared to spontaneous TAAD