Safety and Efficacy of Pulmonary Rehabilitation for Long COVID Patients Experiencing Long-Lasting Symptoms.

Due to the high prevalence and persistence of long COVID, it is important to evaluate the safety and efficacy of pulmonary rehabilitation (PR) for patients who experience long-lasting symptoms more than six months after initial COVID-19 onset. Enrolled patients were admitted for a four-week in-patient-PR due to long COVID symptoms (n = 47). The safety of PR was confirmed by the absence of adverse events. Symptom-related outcomes were evaluated pre- and post-PR with significant score changes for: 6 min walking distance (61 [28 to 103] m), quality of life (mental Short Form-12: 10 [6 to 13], and physical: 9 [6 to 12]), Montreal Cognitive Assessment (1 [0 to 3]), fatigue (MFI-20: -19 [-28 to -8]), dyspnea (DYSPNEA-12: -7 [-9 to -2] and mMRC; -1 [-1 to 0]), Nijmegen questionnaire (-8 [-11 to -5]), anxiety and depression (HADS:-4 [-5 to -2] and -2 [-4 to -1], respectively) and posttraumatic stress disorder checklist scale (-8 [-12 to -4]). At the individual level, the percentage of symptomatic patients for each outcome decreased, with a high response rate, and the number of persistent symptoms per patient was reduced from six at PR initiation to three at the end of the program. Our results show that in-PR is safe and efficient at decreasing long-lasting symptoms experienced by long COVID patients at more than six months after initial disease onset.

High Prevalence of Non-Responders Based on Quadriceps Force after Pulmonary Rehabilitation in COPD.

Pulmonary rehabilitation (PR) in patients with COPD improves quality of life, dyspnea, and exercise tolerance. However, 30 to 50% of patients are "non-responders" (NRs) according to considered variables. Surprisingly, peripheral muscle force is never taken into account to attest the efficacy of PR, despite its major importance. Thus, we aimed to estimate the prevalence of force in NRs, their characteristics, and predictors of non-response. In total, 62 COPD patients were included in this retrospective study (May 2019 to December 2020). They underwent inpatient PR, and their quadriceps isometric maximal force (QMVC) was assessed. The PR program followed international guidelines. Patients with a QMVC increase <7.5 N·m were classified as an NR. COPD patients showed a mean improvement in QMVC after PR (10.08 ± 12.97 N·m; p < 0.001). However, 50% of patients were NRs. NRs had lower pre-PR values for body mass, height, body mass index, PaO2, and QMVC. Non-response can be predicted by low QMVC, high PaCO2, and gender (when male). This model has a sensitivity of 74% and specificity of 81%. The study highlights the considerable number of NRs and potential risk factors for non-response. To systematize the effects, it may be interesting to implement blood gas correction and/or optimize the programs to enhance peripheral and central effects.

Time-Course of Changes in Multidimensional Fatigue and Functional Exercise Capacity and Their Associations during a Short Inpatient Pulmonary Rehabilitation Program.

This study aimed to assess the time-course of changes in multidimensional fatigue and functional exercise capacity and their associations during an inpatient pulmonary rehabilitation (PR) program. Seventy COPD patients from three centres were enrolled for a four-week PR program and were evaluated before (T0) and at the end of each week (T1, T2, T3, and T4). Weekly change in multidimensional fatigue was assessed by the multidimensional inventory questionnaire (MFI-20) and functional exercise capacity by the 6-minute walking distance (6MWD). Reaction time (RT) and heart rate variability (HRV) were also assessed as complementary markers of fatigue. HRV did not change during the study (all p > 0.05). MFI-20 score and RT decreased during the first part of the program (p < 0.001) and levelled off at T2 (all p > 0.05 compared with each preceding time). While 6MWD improved by almost 70% during the first part of the PR, it continued to increase, albeit at a greatly reduced pace, between T2 and T4 (p < 0.05). In parallel, a negative association was found between MFI-20 score and 6MWD at each evaluation time (r ranged from 0.43 to 0.71), with a significantly stronger T3 correlation compared with the other time periods (all p < 0.05). The strengthening of the association between fatigue and functional exercise capacity at T3, which occurred concomitantly with the slowdown of functional exercise capacity improvement, is consistent with a role for fatigue in the limitation of performance changes during PR. The limitation of fatigue during PR is thus an interesting aspect to improve the magnitude of performance changes.

The fall of the summer truffle: Recurring hot, dry summers result in declining fruitbody production of Tuber aestivum in Central Europe.

Global warming is pushing populations outside their range of physiological tolerance. According to the environmental envelope framework, the most vulnerable populations occur near the climatic edge of their species' distributions. In contrast, populations from the climatic center of the species range should be relatively buffered against climate warming. We tested this latter prediction using a combination of linear mixed effects and machine learning algorithms on an extensive, citizen-scientist generated dataset on the fruitbody productivity of the Burgundy (aka summer) truffle (Tuber aestivum Vittad.), a keystone, ectomycorrhizal tree-symbiont occurring on a wide range of temperate climates. T. aestivum's fruitbody productivity was monitored at 3-week resolution over up to 8 continuous years at 20 sites distributed in the climatic center of its European distribution in southwest Germany and Switzerland. We found that T. aestivum fruitbody production is more sensitive to summer drought than would be expected from the breadth of its species' climatic niche. The monitored populations occurring nearly 5°C colder than the edge of their species' climatic distribution. However, interannual fruitbody productivity (truffle mass year-1 ) fell by a median loss of 22% for every 1°C increase in summer temperature over a site's 30-year mean. Among the most productive monitored populations, the temperature sensitivity was even higher, with single summer temperature anomalies of 3°C sufficient to stop fruitbody production altogether. Interannual truffle productivity was also related to the phenology of host trees, with ~22 g less truffle mass for each 1-day reduction in the length of the tree growing season. Increasing summer drought extremes are therefore likely to reduce fruiting among summer truffle populations throughout Central Europe. Our results suggest that European T. aestivum may be a mosaic of vulnerable populations, sensitive to climate-driven declines at lower thresholds than implied by its species distribution model.

Effectiveness comparison of inpatient vs. outpatient pulmonary rehabilitation: a systematic review.

BACKGROUND: Pulmonary rehabilitation (PR) is the cornerstone of nonpharmacological treatments in chronic respiratory disease (CRD) management. PR can be performed in different settings, the most frequent of which are inpatient (inPR) and outpatient (outPR) management. In the literature, these two distinct modalities are generally considered to be the same intervention. Yet, they differ in terms of the length of stay, social support, and the time the patient is not in their normal environment, and the presumed absence of differences in terms of efficacy has never been established. PURPOSE: To identify studies that directly compared the effects of inPR and outPR on patients with all types of CRDs through a systematic review and to synthesize the evidence regarding the effectiveness comparison of both modalities. METHODS: A literature search was performed on PubMed, Web of Science, and Cochrane Library on 24 March 2022. The inclusion criteria were: articles with adults with chronic respiratory disease and comparing inPR versus outPR in at least one PR outcome. RESULTS: Seven hundred thirty-six articles were retrieved from the databases. Six retrospective articles met the inclusion criteria. A best-evidence synthesis (BES) was carried out. Eight outcomes could be found in the included papers. For healthcare burden and refusals, no data could be extracted, and thus no BES was performed. For the eight remaining outcomes, two results were in favor of inPR with moderate evidence (HRQoL and psychological status), three were in favor of no difference between inPR and outPR with moderate or limited evidence (muscle strength, dropouts/adherence, and survival status), and three led to conflicting results (exercise tolerance, dyspnea, and economic costs). CONCLUSION: With the current state of knowledge, the majority of the studies converge towards an absence of differences between inPR and outPR or in favor of inPR for seven out of eight outcomes, albeit with moderate, limited, or conflicting evidence. The greater effectiveness of inPR for some outcomes will have to be confirmed in a well-designed RCT in order to orient public health policies in terms of the development of PR with the best evidence-based medicine approach. TRIAL REGISTRATION: PROSPERO: CRD42020166546 .

Hidden fairy rings and males-Genetic patterns of natural Burgundy truffle (Tuber aestivum Vittad.) populations reveal new insights into its life cycle.

Burgundy truffles are heterothallic ascomycetes that grow in symbiosis with trees. Despite their esteemed belowground fruitbodies, the species' complex lifecycle is still not fully understood. Here, we present the genetic patterns in three natural Burgundy truffle populations based on genotyped fruitbodies, ascospore extracts and ectomycorrhizal root tips using microsatellites and the mating-type locus. Distinct genetic structures with high relatedness in close vicinity were found for females (forming the fruitbodies) and males (fertilizing partner as inferred from ascospore extracts), with high genotypic diversity and annual turnover of males, suggesting that ephemeral male mating partners are germinating ascospores from decaying fruitbodies. The presence of hermaphrodites and the interannual persistence of a few males suggest that persistent mycelia may sporadically also act as males. Only female or hermaphroditic individuals were detected on root tips. At one site, fruitbodies grew in a fairy ring formed by a large female individual that showed an outward growth rate of 30 cm per year, with the mycelium decaying within the ring and being fertilized by over 50 male individuals. While fairy ring structures have never been shown for truffles, the genetics of Burgundy truffle populations support a similar reproductive biology as those of other highly prized truffles.

Association between long-term oxygen therapy provided outside the guidelines and mortality in patients with COPD.

INTRODUCTION: Hypoxaemia is a frequent complication of chronic obstructive pulmonary disease (COPD). To prevent its consequences, supplemental oxygen therapy is recommended by international respiratory societies. However, despite clear recommendations, some patients receive long-term oxygen therapy (LTOT), while they do not meet prescription criteria. While evidence suggests that acute oxygen supply at high oxygenation targets increases COPD mortality, its chronic effects on COPD mortality remain unclear. Thus, the study will aim to evaluate through a systematic review and individual patient data meta-analysis (IPD-MA), the association of LTOT prescription outside the guidelines on survival over time in COPD. METHODS: Systematic review and IPD-MA will be conducted according to Preferred Reporting Items for a Systematic Review and Meta-Analyses IPD guidelines. Electronic databases (PubMed, Web of Science, EMBASE, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, OpenGrey and BioRxiv/MedRxix) will be scanned to identify relevant studies (cohort of stable COPD with arterial oxygen tension data available, with indication of LTOT filled out at the moment of the study and with a survival follow-up). The anticipated search dates are January-February 2022. The main outcome will be the association between LTOT and time to all-cause mortality according to hypoxaemia severity, after controlling for potential covariates and all available clinical characteristics. Quantitative data at the level of the individual patient will be used in a one-step approach to develop and validate a prognostic model with a Cox regression analysis. The one-step IPD-MA will be conducted to study the association and the moderators of association between supplemental oxygen therapy and mortality. Multilevel survival analyses using Cox-mixed effects models will be performed. ETHICS AND DISSEMINATION: As a protocol for a systematic review, a formal ethics committee review is not required. Only studies with institutional approval from an ethics committee and anonymised IPD will be included. Results will be disseminated through peer-reviewed publications and presentations in conferences. PROSPERO REGISTRATION NUMBER: CRD42020209823.

The role of personality traits in inpatient pulmonary rehabilitation response in patients with chronic obstructive pulmonary disease.

BACKGROUND: The effectiveness of pulmonary rehabilitation (PR) is a critical issue for chronic obstructive pulmonary disease (COPD) patients. However, PR response is marked by a strong heterogeneity, partially unexplained to date. We hypothesized that personality traits defined by the Five-Factor Model could modulate the effect of inpatient-PR. OBJECTIVE: The aim was to assess the associations between these five personality traits and PR outcomes. METHODS: 74 persons with COPD admitted for a 5-week inpatient PR program had a personality assessment at the start of the program (T1). Exercise capacity, quality of life, sensory and affective dyspnea dimensions were assessed at T1 and at the end of the program (T2). Their evolution was evaluated using the delta score between T2 and T1. PR response was defined using the minimal clinically important change score for each of them. A composite response was established distinguishing the poor responders' group, made of patients who responded to 0, 1 or 2 parameters and the good responders' group, with patients who responded on 3 or 4 indicators. RESULTS: Logistic regressions analyses highlighted that those with a high level of openness [OR = 0.36, 95% CI = 0.15-0.74, p < 0.01] were less likely to respond on quality of life, controlling for socio-demographic factors and the severity of the disease. CONCLUSION: This study shows that the investigation of the personality constitutes an interesting perspective for better understanding the interindividual differences observed between patients in the PR response. Tailoring clinical intervention to the patient's personality could be a promising prospect for optimizing PR effectiveness.

Eco-archaeological excavation techniques reveal snapshots of subterranean truffle growth.

Despite its status as a highly-prized and coveted fungi in gastronomy, many aspects of the subterranean life cycle of the Burgundy truffle (Tuber aestivum) are still unknown, because in situ observations of the formation and maturation of truffle fruitbodies remain difficult. Here, we adopted a suite of archaeological fine-scale excavating techniques to provide unique spatiotemporal snapshots of Burgundy truffle growth at three sites in southern Germany. We also recorded the relative position, fresh weight, maturity level and genotype composition of all excavated fruitbodies. Varying by a factor of thousand, the fresh weight of 73 truffle ranged from 0.1 to 103.2 g, with individual maturity levels likely representing different life cycle stages from completely unripe to fully ripe and even decaying. While only a slightly positive relationship between fruitbody weight and maturity level was found, our results suggest that genetically distinct specimens can exhibit different life cycle stages at the same period of time and under the same environmental conditions. We therefore argue that truffles are likely able to grow, mature and ripe simultaneously between early summer and late winter of the following year. Our case study should encourage further eco-archaeological truffle excavations under different biogeographic settings and at different seasons of the year to gain deeper insights into the fungi's subterranean ecology. The expected cross-disciplinary findings will help truffle hunters and farmers to improve their harvest practices and management strategies.

Climate Change, Physical Activity and Sport: A Systematic Review.

BACKGROUND: Climate change impacts are associated with dramatic consequences for human health and threaten physical activity (PA) behaviors. OBJECTIVE: The aims of this systematic review were to present the potential bidirectional associations between climate change impacts and PA behaviors in humans and to propose a synthesis of the literature through a conceptual model of climate change and PA. METHODS: Studies published before October 2020 were identified through database searches in PubMed, PsycARTICLES, CINAHL, SPORTDiscus, GreenFILE, GeoRef, Scopus, JSTOR and Transportation Research Information Services. Studies examining the associations between PA domains and climate change (e.g., natural disasters, air pollution, and carbon footprint) were included. RESULTS: A narrative synthesis was performed and the 74 identified articles were classified into 6 topics: air pollution and PA, extreme weather conditions and PA, greenhouse gas emissions and PA, carbon footprint among sport participants, natural disasters and PA and the future of PA and sport practices in a changing world. Then, a conceptual model was proposed to identify the multidimensional associations between climate change and PA as well as sport practices. Results indicated a consistent negative effect of air pollution, extreme temperatures and natural disasters on PA levels. This PA reduction is more severe in adults with chronic diseases, higher body mass index and the elderly. Sport and PA communities can play an important mitigating role in post-natural disaster contexts. However, transport related to sport practices is also a source of greenhouse gas emissions. CONCLUSION: Climate change impacts affect PA at a worldwide scale. PA is observed to play both a mitigation and an amplification role in climate changes. TRIAL REGISTRATION NUMBER: PROSPERO CRD42019128314.

Orchard Conditions and Fruiting Body Characteristics Drive the Microbiome of the Black Truffle Tuber aestivum.

Truffle fungi are well known for their enticing aromas partially emitted by microbes colonizing truffle fruiting bodies. The identity and diversity of these microbes remain poorly investigated, because few studies have determined truffle-associated bacterial communities while considering only a small number of fruiting bodies. Hence, the factors driving the assembly of truffle microbiomes are yet to be elucidated. Here we investigated the bacterial community structure of more than 50 fruiting bodies of the black truffle Tuber aestivum in one French and one Swiss orchard using 16S rRNA gene amplicon high-throughput sequencing. Bacterial communities from truffles collected in both orchards shared their main dominant taxa: while 60% of fruiting bodies were dominated by α-Proteobacteria, in some cases the ß-Proteobacteria or the Sphingobacteriia classes were the most abundant, suggesting that specific factors (i.e., truffle maturation and soil properties) shape differently truffle-associated microbiomes. We further attempted to assess the influence in truffle microbiome variation of factors related to collection season, truffle mating type, degree of maturation, and location within the truffle orchards. These factors had differential effects between the two truffle orchards, with season being the strongest predictor of community variation in the French orchard, and spatial location in the Swiss one. Surprisingly, genotype and fruiting body maturation did not have a significant effect on microbial community composition. In summary, our results show, regardless of the geographical location considered, the existence of heterogeneous bacterial communities within T. aestivum fruiting bodies that are dominated by three bacterial classes. They also indicate that factors shaping microbial communities within truffle fruiting bodies differ across local conditions.

Pezizomycetes genomes reveal the molecular basis of ectomycorrhizal truffle lifestyle.

Tuberaceae is one of the most diverse lineages of symbiotic truffle-forming fungi. To understand the molecular underpinning of the ectomycorrhizal truffle lifestyle, we compared the genomes of Piedmont white truffle (Tuber magnatum), Périgord black truffle (Tuber melanosporum), Burgundy truffle (Tuber aestivum), pig truffle (Choiromyces venosus) and desert truffle (Terfezia boudieri) to saprotrophic Pezizomycetes. Reconstructed gene duplication/loss histories along a time-calibrated phylogeny of Ascomycetes revealed that Tuberaceae-specific traits may be related to a higher gene diversification rate. Genomic features in Tuber species appear to be very similar, with high transposon content, few genes coding lignocellulose-degrading enzymes, a substantial set of lineage-specific fruiting-body-upregulated genes and high expression of genes involved in volatile organic compound metabolism. Developmental and metabolic pathways expressed in ectomycorrhizae and fruiting bodies of T. magnatum and T. melanosporum are unexpectedly very similar, owing to the fact that they diverged ~100 Ma. Volatile organic compounds from pungent truffle odours are not the products of Tuber-specific gene innovations, but rely on the differential expression of an existing gene repertoire. These genomic resources will help to address fundamental questions in the evolution of the truffle lifestyle and the ecology of fungi that have been praised as food delicacies for centuries.

New Insights into the Complex Relationship between Weight and Maturity of Burgundy Truffles (Tuber aestivum).

Despite an increasing demand for Burgundy truffles (Tuber aestivum), gaps remain in our understanding of the fungus' overall lifecycle and ecology. Here, we compile evidence from three independent surveys in Hungary and Switzerland. First, we measured the weight and maturity of 2,656 T. aestivum fruit bodies from a three-day harvest in August 2014 in a highly productive orchard in Hungary. All specimens ranging between 2 and 755 g were almost evenly distributed through five maturation classes. Then, we measured the weight and maturity of another 4,795 T. aestivum fruit bodies harvested on four occasions between June and October 2015 in the same truffière. Again, different maturation stages occurred at varying fruit body size and during the entire fruiting season. Finally, the predominantly unrelated weight and maturity of 81 T. aestivum fruit bodies from four fruiting seasons between 2010 and 2013 in Switzerland confirmed the Hungarian results. The spatiotemporal coexistence of 7,532 small-ripe and large-unripe T. aestivum, which accumulate to ~182 kg, differs from species-specific associations between the size and ripeness that have been reported for other mushrooms. Although size-independent truffle maturation stages may possibly relate to the perpetual belowground environment, the role of mycelial connectivity, soil property, microclimatology, as well as other abiotic factors and a combination thereof, is still unclear. Despite its massive sample size and proof of concept, this study, together with existing literature, suggests consideration of a wider ecological and biogeographical range, as well as the complex symbiotic fungus-host interaction, to further illuminate the hidden development of belowground truffle fruit bodies.

Ectomycorrhizal ecology is imprinted in the genome of the dominant symbiotic fungus Cenococcum geophilum.

The most frequently encountered symbiont on tree roots is the ascomycete Cenococcum geophilum, the only mycorrhizal species within the largest fungal class Dothideomycetes, a class known for devastating plant pathogens. Here we show that the symbiotic genomic idiosyncrasies of ectomycorrhizal basidiomycetes are also present in C. geophilum with symbiosis-induced, taxon-specific genes of unknown function and reduced numbers of plant cell wall-degrading enzymes. C. geophilum still holds a significant set of genes in categories known to be involved in pathogenesis and shows an increased genome size due to transposable elements proliferation. Transcript profiling revealed a striking upregulation of membrane transporters, including aquaporin water channels and sugar transporters, and mycorrhiza-induced small secreted proteins (MiSSPs) in ectomycorrhiza compared with free-living mycelium. The frequency with which this symbiont is found on tree roots and its possible role in water and nutrient transport in symbiosis calls for further studies on mechanisms of host and environmental adaptation.

Recovery of trees from drought depends on belowground sink control.

Climate projections predict higher precipitation variability with more frequent dry extremes(1). CO2 assimilation of forests decreases during drought, either by stomatal closure(2) or by direct environmental control of sink tissue activities(3). Ultimately, drought effects on forests depend on the ability of forests to recover, but the mechanisms controlling ecosystem resilience are uncertain(4). Here, we have investigated the effects of drought and drought release on the carbon balances in beech trees by combining CO2 flux measurements, metabolomics and (13)CO2 pulse labelling. During drought, net photosynthesis (AN), soil respiration (RS) and the allocation of recent assimilates below ground were reduced. Carbohydrates accumulated in metabolically resting roots but not in leaves, indicating sink control of the tree carbon balance. After drought release, RS recovered faster than AN and CO2 fluxes exceeded those in continuously watered trees for months. This stimulation was related to greater assimilate allocation to and metabolization in the rhizosphere. These findings show that trees prioritize the investment of assimilates below ground, probably to regain root functions after drought. We propose that root restoration plays a key role in ecosystem resilience to drought, in that the increased sink activity controls the recovery of carbon balances.

Fine-scale genetic structure of natural Tuber aestivum sites in southern Germany.

Although the Burgundy truffle (Tuber aestivum) is an ectomycorrhizal fungus of important economic value, its subterranean life cycle and population biology are still poorly understood. Here, we determine mating type and simple sequence repeat (SSR) maternal genotypes of mapped fruiting bodies to assess their genetic structure within two naturally colonized forest sites in southern Germany. Forty-one genotypes were identified from 112 fruiting bodies. According to their mating types, the maternal genotypes were aggregated only in one population. Genotypic diversity of individuals that mostly were small and occurred in 1 out of 2 years of sampling was high. Although these results suggested a ruderal colonization strategy, some genets spread several hundred meters. This result indicates that, besides sexual spore dispersal, vegetative growth or spreading by mycelial propagules contributes to dissemination. In one site, fewer individuals with a tendency to expand genets belonging to only one genetic group were observed. In the second site, numerous small individuals were found and were grouped into two clearly differentiated genetic groups that were spatially intermingled. Forest characteristics and disturbances are possible reasons for the observed genetic patterns. Our findings contribute to a better understanding of the biology of one of the most widespread and commercially important truffle species. This knowledge is critical for establishing and maintaining sustainable long-term truffle cultivations.

SSR-based identification of genetic groups within European populations of Tuber aestivum Vittad.

Tuber species are ectomycorrhizal ascomycetes establishing relationships with different host trees and forming hypogeous fruiting bodies known as truffles. Among Tuber species, Tuber aestivum Vittad. has a wide distributional range being found naturally all over Europe. Here, we performed large-scale population genetic analyses in T. aestivum to (i) investigate its genetic diversity at the European scale, (ii) characterize its genetic structure and test for the presence of ecotypes and (iii) shed light into its demographic history. To reach these goals, 230 ascocarps from different populations were genotyped using 15 polymorphic simple sequence repeat markers. We identified 181 multilocus genotypes and four genetic groups which did not show a clear geographical separation; although, one of them was present exclusively in Southeast France, Italy and Spain. Fixation index values between pairs of genetic groups were generally high and ranged from 0.29 to 0.45. A significant deficit of heterozygosity indicated a population expansion instead of a recent population bottleneck, suggesting that T. aestivum is not endangered in Europe, not even in Mediterranean regions. Our study based on a large-scale population genetic analysis suggests that genetically distinct populations and likely ecotypes within T. aestivum are present. In turn, this study paves the way to future investigations aimed at addressing the biological and/or ecological factors that have concurred in shaping the population genetic structure of this species. Present results should also have implications for the truffle market since defining genetic markers are now possible at least for some specific T. aestivum genetic groups.

Fine-scale spatial genetic structure analysis of the black truffle Tuber aestivum and its link to aroma variability.

Truffles are symbiotic fungi in high demand by food connoisseurs. Improving yield and product quality requires a better understanding of truffle genetics and aroma biosynthesis. One aim here was to investigate the diversity and fine-scale spatial genetic structure of the Burgundy truffle Tuber aestivum. The second aim was to assess how genetic structuring along with fruiting body maturation and geographical origin influenced single constituents of truffle aroma. A total of 39 Burgundy truffles collected in two orchards were characterized in terms of aroma profile (SPME-GC/MS) and genotype (microsatellites). A moderate genetic differentiation was observed between the populations of the two orchards. An important seasonal and spatial genetic structuring was detected. Within one orchard, individuals belonging to the same genet were generally collected during a single season and in the close vicinity from each other. Maximum genet size nevertheless ranged from 46 to 92 m. Geographical origin or maturity only had minor effects on aroma profiles but genetic structuring, specifically clonal identity, had a pronounced influence on the concentrations of C8 - and C4 -VOCs. Our results highlight a high seasonal genetic turnover and indicate that the aroma of Burgundy truffle is influenced by the identity of single clones/genets.

First identification of polymorphic microsatellite markers in the Burgundy truffle, Tuber aestivum (Tuberaceae).

PREMISE OF THE STUDY: Tuber aestivum, the most common truffle in Europe, plays an important role in the commercial truffle market. For the first time, microsatellite primers were developed to investigate polymorphism within this species. • METHODS AND RESULTS: Using direct shotgun pyrosequencing, 15 polymorphic microsatellites were identified out of the 7784 perfect microsatellites present in the 534620 reads obtained. Tested on 75 samples, these microsatellites were highly polymorphic. The number of alleles varied from four to 15, and the expected heterozygosity ranged from 0.266 to 0.620. A multilocus analysis allowed the identification of 63 genotypes over the 75 samples analyzed. • CONCLUSIONS: Direct shotgun pyrosequencing is a fast and relatively low-cost technique allowing identification of microsatellites in nonmodel species. The microsatellites developed in this study will be useful in population genetic studies to infer the evolutionary history of this species.