Castanea Sativa Research Articles

Insights into the digestion of chestnut (Castanea sativa) shells bioactive extracts—ultrasound vs. microwave‐assisted extraction

SummaryIn the current study, polyphenols were extracted from chestnut (Castanea sativa) shells (CSS) by two eco‐friendly techniques, namely microwave‐assisted extraction (MAE) and ultrasound‐assisted extraction (UAE). The bioaccessibility, phenolic composition and bioactivity of CSS extracts were explored upon in vitro gastrointestinal digestion considering a future nutraceutical use. The phenolic and flavonoid concentrations, bioaccessibility and antioxidant/antiradical properties of both extracts decreased during digestion. The bioaccessibility was 25% and 26%, respectively, for UAE and MAE extracts. The phenolic profile demonstrated that gallic acid, caftaric acid and catechin were the most bioaccessible compounds for both extraction techniques. The CSS extracts unveiled notable radicals scavenging efficiency, particularly against HOCl (18.32–75.44% inhibition) and ONOO− (16.78–86.11% inhibition), as well as hypoglycaemic (6.95–17.99% α‐amylase inhibition) and neuroprotective (16.44–54.66% AChE inhibition) properties upon digestion. Considering the undigested extracts, the UAE extract revealed better results than the MAE extract. Oppositely, among digested fractions the MAE digests disclosed the most promising outcomes. The remarkable contribution of phenolic compounds to the bioactivity of CSS extracts after in vitro digestion was proved by heatmap correlations, indicating that their pro‐healthy properties were modified after gastrointestinal digestion, being ascribed to the distinct phenolic composition. This study evaluates, for the first time, the impact of in vitro gastrointestinal digestion on the bioaccessibility and bioactivity of phenolics‐rich CSS extracts prepared by UAE and MAE.

Classification and Status by Geological Periods Relicts, Rare Species of Zakatala and Belokan Districts

The article provides data on period III relicts and rare tree and shrub species common in the forest ecosystems of the Zakatala and Belokan districts of Azerbaijan, and their classification and status by geological periods is given. As a result of research and analysis, the species Taxus baccata L., Hedera pastuchovii Woronow ex Woronow and Smilax excelsa L. were included in the relicts of the Poltava flora. In the forest ecosystems of the study areas, 6 tree and shrub relict species belonging to 6 families and 6 genera of the subtropical evergreen Poltava flora (mesothermal relicts of the Arctic flora of the III period) were identified: Taxus baccata L., Platanus orientalis L., Punica granatum L., Hedera pastuchovii Woronow ex Woronow, Smilax excelsa L. and Diospyros lotus L. With the exception of Smilax excelsa L., other 5 species are listed in the Red Book of the Azerbaijan Republic. In the Zakatala and Belokan districts, relict tree and shrub plants belonging to 15 families, 23 genera and 30 species of Arctic and deciduous Turgai flora (mesothermal relicts of the Arctic flora of the III period) are widespread. Of these, 10 species (Pinus kochiana Klotzsch ex K. Koch = Pinus sylvestris var. hamata Steven, Fraxinus coriariifolia Scheele, Castanea sativa Mill., Quercus iberica Steven ex M. Bieb., Pterocarya pterocarpa (Michx.) Kunth ex Iljinsk., Juglans regia L., Acer pseudoplatanus L., Acer hyrcanum Fisch. ex C. A. Mey., Corylus colurna L., Vitis vinifera L., are considered rare plants of Azerbaijan. It was established that 38 rare tree and shrub species belonging to 35 there are 23 families.

Boscalid + Pyraclotrobin Resistance and Expression of Succinate Dehyrogenase Genes (sdhA and sdhB) in Chestnut Blight Fungus Cryphonectria parasitica

Sweet chestnut, Castanea sativa Mill., is a significant species in Türkiye. The tree has been encountered with numerous diseases. Chestnut blight, caused by Cryphonectria parasitica (Murrill) M. E. Barr, is one of the most common diseases having spread to every chestnut-growing region. In this study, the effects of Bellis® (25.2% Boscalid + 12.8% Pyraclotrobin), a fungicide commonly used in plant disease control, were evaluated at different doses (10 ppm and 50 ppm) against the chestnut blight agent C. parasitica, which had not been previously studied for its effects in vitro. The isolates included two virulent strains (Cp1_2023, Cp2_2023) and two hypovirulent strains (Cp7_2023, Cp9_2023). The effects of Boscalid + Pyraclotrobin on the mycelial growth of the pathogenic fungus were determined for the first time in vitro, and these effects were detected at the sdhA and sdhB genes expression level. The results showed that the mycelial growth and pathogenicity of C. parasitica isolates in the fungicide-treated medium were consistent with the gene expression profile. Specifically, the virulent Cp1_2023 isolate exhibited higher mycelial growth, pathogenicity, and gene expression levels compared to the other isolate. In conclusion, it is recommended to conduct more detailed studies before using fungicides and to employ them in controlled environments.

Identification of a Unique Genomic Region in Sweet Chestnut (Castanea sativa Mill.) That Controls Resistance to Asian Chestnut Gall Wasp Dryocosmus kuriphilus Yasumatsu.

The Asian chestnut gall wasp (ACGW) (Hymenoptera Dryocosmus kuriphilus Yasumatsu) is a severe pest of sweet chestnut (Castanea sativa Mill.) with a strong impact on growth and nut production. A comparative field trial in Central Italy, including provenances from Spain, Italy, and Greece, was screened for ACGW infestation over consecutive years. The Greek provenance Hortiatis expressed a high proportion of immune plants and was used to perform a genome-wide association study based on DNA pool sequencing (Pool-GWAS) by comparing two DNA pools from 25 susceptible and 25 resistant plants. DNA pools were sequenced with 50X coverage depth. Sequence reads were aligned to a C. mollissima reference genome and the pools were compared to identify SNPs associated with resistance. Twenty-one significant SNPs were identified and highlighted a small genomic region on pseudochromosome 3 (Chr 3), containing 12 candidate genes of three gene families: Cytochrome P450, UDP-glycosyltransferase, and Rac-like GTP-binding protein. Functional analyses revealed a putative metabolic gene cluster related to saccharide biosynthesis in the genomic regions associated with resistance that could be involved in the production of a toxic metabolite against parasites. The comparison with previous genetic studies confirmed the involvement of Chr 3 in the control of resistance to ACGW.

Frictional Behavior of Chestnut (Castanea sativa Mill.) Sawn Timber for Carpentry and Mechanical Joints in Service Class 2

Wood is poised to become a material of choice for future construction. When appropriately managed, it is a renewable material with unique mechanical properties. Thus, there has been a growing demand for hardwoods, including Castanea sativa Mill., the focal point of this investigation, for structural applications. Albeit in a limited capacity, Eurocode 5-2 offers friction coefficients for softwoods, but it falls short for hardwoods. These coefficients play a critical role in numerical simulations involving friction, enabling the optimization of joints and, by extension, the overall structural integrity. Test samples were evaluated at 15% and 18% moisture content (Service Class 2) for various orientations of timber-to-timber and timber-to-steel friction. The results provide an experimental database for numerical simulations and highlight the influence of moisture on the stick–slip phenomenon, which was absent for the timber-to-timber tests, as well as on the rising friction values. At 18%, the static and kinetic coefficients were 0.70 and 0.48 for timber-to-timber and 0.5 and 0.50 for timber-to-steel. The increase was around 50% for timber-to-timber friction and over 170% for timber-to-steel pairs. Moreover, the findings proved a relationship between both coefficients and the validity of the linear estimation approach within the 12–18% moisture commonly applied to softwoods.

Wood Distillate Mitigates Ozone-Induced Visible and Photosynthetic Plant Damage: Evidence from Ozone-Sensitive Tobacco (Nicotiana tabacum L.) BelW3

The use of wood distillate (WD) is emerging as a valuable strategy for protecting horticultural crops from the oxidizing effects of ozone (O3). To fully understand its effectiveness, extensive testing on different plant species is needed. As a viable interim measure, an assessment of WD efficacy in model plants can be made until species-specific results become available. The aim of this study is to evaluate the ability of WD derived from forest wood, including chestnut (Castanea sativa Mill.) wood, to protect the ozone-sensitive tobacco plant (Nicotiana tabacum L.) BelW3 from the oxidizing effects of O3, using the ozone-resistant tobacco plant BelB as a benchmark. The protective effect was evaluated during treatment applications and three weeks after these were completed. Ten BelW3 and five BelB plants were grown just outside Parma from June to October 2023, a period when average maximum O3 concentrations were at least 120 ppb. Starting from July, five BelW3 plants were sprayed weekly with WD at 0.2% for two months. Morphometric and photosynthetic measurements were then taken after six and 11 weeks from the beginning of treatments and three weeks after the end to assess protection persistence (if any). BelW3 showed a significant effect of O3 compared to BelB plants for both morphometric and photosynthetic measurements, exhibiting increased necrotic areas on the leaf blade, reduced number of viable leaves, reduced average plant height, together with reduced chlorophyll content and impaired photosynthetic system functionality. BelW3 plants also showed a significant decrease in the efficiency of parameters related to PSII and PSI when compared to BelB. Wood distillate application, however, successfully mitigated O3 effects on BelW3, as revealed by morphometric and photosynthetic values, which were in line with those observed in BelB. Notably, WD protective effect persisted 3 weeks after treatment cessation, highlighting the short-term protective capacity of the distillate against the oxidative action of O3.

Analysis of the efficiency of different Oleaginous seeds and shells for use as natural coagulants

The research problem is to reduce the use of chemical coagulants by seeking more sustainable alternatives to water treatment. The use of Moringa oleifera (MO) is a good alternative coagulant agent, indicated in the water treatment system, in its clarification process, in addition to being biodegradable, but there is a need to look for other seeds that also have potential for be used as natural coagulants, in this context, it is justified to study other typical seeds from Portugal, where this study was carried out, to be used as an alternative natural coagulant. The hypothesis of this project is: among the typically European seeds selected for evaluation, seeds with high potential for use as a natural coagulant for use in water treatment will be found. This project aims to identify seeds, typical of Portugal, with similar potential to Moringa oleifera Lam to be used as a natural coagulant. The project was carried out in partnership with UFS, IFS and ISEP, where experiments were carried out with synthetic water with turbidity ranging from 40 to 350 NTU. The seeds used were four different types of European chestnuts, American and Portuguese nuts, plantain and Moringa oleifera, in addition to chestnut and walnut shells. From the results found, the Spanish chestnuts stand out with a turbidity removal efficiency of up to 69.8% in high turbidity water, in addition to the MO with a removal efficiency of 89.8% in high turbidity water.

Harmful self-pollination drives gynodioecy in European chestnut, a self-incompatible tree.

Gynodioecy is a rare sexual system in which two genders (sensu Lloyd, 1980), cosexuals and females, coexist. To survive, female plants must compensate for their lack of siring capacity and male attractiveness. In European chestnut (Castanea sativa), an outcrossing tree, self-pollination reduces fruit set in cosexual individuals because of late-acting self-incompatibility and early inbreeding depression. Could this negative sexual interaction explain the presence of females in this species? We studied gender variation in wild populations of European chestnut. In addition, we compared fruit set (the proportion of flowers giving fruits) and other key female fitness components as well as reproductive allocation between genders. We then performed emasculation experiments in cosexual trees, by removing nectar-producing fertile male inflorescences. We also removed sterile but nectar-producing male inflorescences from female trees, as a control. We found a highly variable proportion of male-sterile individuals in the wild in European chestnut. In the experimental plot, trees from each gender had similar size, flower density, and burr set, but different fruit set. Removing nectar-producing male inflorescences from branches or entire trees increased fruit set in cosexual but not in female trees. These results show that self-pollination impairs fruit set in cosexual trees. Female trees avoid these problems as they do not produce pollen but continue to attract pollinators thanks to their rewarding male-sterile inflorescences, resulting in a much higher fruit set than in cosexuals. This demonstrates that even outcrossed plants can benefit from the cessation of self-pollination, to the point that unisexuality can evolve.

Spectral Library of Plant Species from Montesinho Natural Park in Portugal

In this work, we present and describe a spectral library (SL) with 15 vascular plant species from Montesinho Natural Park (MNP), a protected area in Northeast Portugal. We selected species from the vascular plants that are characteristic of the habitats in the MNP, based on their prevalence, and also included one invasive species: Alnus glutinosa (L.) Gaertn, Castanea sativa Mill., Cistus ladanifer L., Crataegus monogyna Jacq., Frangula alnus Mill., Fraxinus angustifolia Vahl, Quercus pyrenaica Willd., Quercus rotundifolia Lam., Trifolium repens L., Arbutus unedo L., Dactylis glomerata L., Genista falcata Brot., Cytisus multiflorus (L’Hér.) Sweet, Erica arborea L., and Acacia dealbata Link. We collected spectra (300–2500 nm) from five records per leaf and leaf side, which resulted in 538 spectra compiled in the SL. Additionally, we computed five vegetation indices from spectral data and analysed them to highlight specific characteristics and differences among the sampled species. We detail the data repository information and its organisation for a better understanding of the data and to facilitate its use. The SL structure can add valuable information about the selected plant species in MNP, contributing to conservation purposes. This plant species SL is publicly available in Zenodo platform.

Quantitative and Qualitative Determination of Polyphenolic Compounds in Castanea sativa Leaves and Evaluation of Their Biological Activities

The aim of the study was to evaluate the polyphenol profile of Castanea sativa leaf methanolic extract and further evaluate its biological activities in vitro. After purification with an RP-18 resin, the extract was assessed for its polyphenol profile by UPLC-PDA-MS/MS, as well as for the antioxidant potential (ABTS, CUPRAC, ChA, ROS scavenging methods), anticancer, antiobesity, antidiabetic and antimicrobial potential. Eighteen polyphenols were identified and the dominant compounds were chestatin followed by quercetin 3-O-glucoside. The total phenolic content of the extract showed a value of 1426.55 mg/100 g d.w. The obtained preparation showed the ability to scavenge O2•− (0.067 mg/mL) and OH• (0.207 mg/mL) radicals and had a stronger anti-obesity than anti-diabetic effect. Additionally, this extract exhibited a strong anticancer activity against the Caco-2 line (153.54 µg/mL), with anti-migratory and anti-proliferative activity. In turn, among the tested strains, the highest activity was demonstrated against Staphylococcus aureus. Moreover, the effects demonstrated were strongly dependent on the content of polyphenols. In conclusion, C. sativa is a promising source of natural antioxidant, antibacterial, antiobesity, antidiabetic and chemopreventive compounds for food-pharma industry; however, further experimental studies are needed to validate its pharmacological properties.

Potential change of chestnut (Castanea sativa Mill.) distribution areas in Kastamonu due to global climate change

Climate change, which is effective on a global scale, threatens almost all living things and ecosystems directly or indirectly. Forests are among the ecosystems that are predicted to be most affected by climate change. In this study, it was aimed to determine the current status of chestnut distribution areas in Kastamonu Forestry Regional Directorate, which is the Forestry Regional Directorate with the highest production in Türkiye, and the change in suitable distribution areas due to global climate change. In the study, in addition to the current suitable distribution areas of chestnut distribution areas and the current distribution area, the suitable distribution areas in 2040, 2070 and 2100 according to SSP 126, SSP 370 and SSP 585 scenarios were determined. The results of the study show that there will be a significant decrease in the suitable distribution areas of chestnut populations in Kastamonu due to the effects of climate change. Therefore, in order to prevent individual, population and species losses in the future, it is recommended to make necessary arrangements in forest management plans by taking the results of the study into consideration.

Investigation into the Anti-Acne Effects of Castanea sativa Mill Leaf and Its Pure Ellagitannin Castalagin in HaCaT Cells Infected with Cutibacterium acnes.

Acne vulgaris is a prevalent skin disorder affecting many young individuals, marked by keratinization, inflammation, seborrhea, and colonization by Cutibacterium acnes (C. acnes). Ellagitannins, known for their antibacterial and anti-inflammatory properties, have not been widely studied for their anti-acne effects. Chestnut (Castanea sativa Mill., C. sativa), a rich ellagitannin source, including castalagin whose acne-related bioactivity was previously unexplored, was investigated in this study. The research assessed the effect of C. sativa leaf extract and castalagin on human keratinocytes (HaCaT) infected with C. acnes, finding that both inhibited IL-8 and IL-6 release at concentrations below 25 μg/mL. The action mechanism was linked to NF-κB inhibition, without AP-1 involvement. Furthermore, the extract displayed anti-biofilm properties and reduced CK-10 expression, indicating a potential role in mitigating inflammation, bacterial colonization, and keratosis. Castalagin's bioactivity mirrored the extract's effects, notably in IL-8 inhibition, NF-κB inhibition, and biofilm formation at low μM levels. Other polyphenols, such as flavonol glycosides identified via LC-MS, might also contribute to the extract's biological activities. This study is the first to explore ellagitannins' potential in treating acne, offering insights for developing chestnut-based anti-acne treatments pending future in vivo studies.

Quantifying Asian chestnut gall wasp (Dryokosmus kuriphilus Yasumatsu) impact on fruit yield and on tree growth using terrestrial LiDAR

The Asian chestnut gall wasp is an invasive pest that causes ecological and economic losses in the management of the sweet chestnut (Castanea sativa Mill.). The pest therefore needs to be monitored in order to assess its impact on tree growth and fruit yield. As part of this work, we propose an infestation level classification based on the number of galls per branch. For two sweet chestnut orchards infested by the wasp, terrestrial light detection and ranging (LiDAR) data were used to calculate tree growth and fruit yield was quantified in terms of nuts and burrs. The tree growth and fruit yield variables were statistically analysed to determine the impact of different infestation levels on these variables, and differences between pairs of infestation levels were tested for significance. Negative correlations were found for the fruit yield variables with infestation indicators, while positive correlations were found for the tree growth variables. Significant differences were observed in fruit yield and tree growth variables associated with different infestation levels.

First report of Bretziella fagacearum infecting chestnut in Michigan.

In the summer of 2021, a 20-year-old 'Colossal' (Castanea sativa × C. crenata hybrid) tree in a commercial chestnut orchard in northwest Michigan suddenly declined. Until 2023, an additional 26 adjacent trees declined, suggesting the occurrence of root-graft transmission of the pathogen. The initial wilting of leaves progressed to complete tree death in about 10 days. Symptoms included wilting, and bronzing, followed by tanning starting at leaf apex and margins, with significant defoliation. Sometimes black-to-brown streaks of discoloration appear in the sapwood, with no signs of mycelial mat production on dead trees. Branches from symptomatic trees in two different areas of the orchard were submitted to Plant and Pest Diagnostics at Michigan State University. Bretziella fagacearum (Bretz) Z.W. de Beer, Marinc., T.A. Duong & M.J. Wingf. was detected in both samples using nested PCR (Wu et al. 2011) and qPCR (Bourgault et al. 2022). The products of the nested PCR were sequenced (GenBank accession nos. OR522695-OR522696) and BLASTn search results showed 100% identity to an ex-type strain of B. fagacearum (MH865866). Surface-sterilized discolored sapwood chips were plated on acidified potato dextrose agar (aPDA). Bretziella fagacearum was consistently recovered; colony and endoconidia morphology aligned with the description of the pathogen (De Beer et al. 2017). A pure culture (BF277) was obtained for inoculation experiments. To confirm pathogenicity, 10 'Colossal' chestnut seedlings (average stem diameter of 9 mm) were inoculated in the greenhouse with a 14-day old culture of BF277. Using a conical drill bit, two 0.4 mm diameter holes were drilled, one was 5 cm above the soil line at a 45° angle and the other was on the opposite side of the stem at least 10 cm above the soil line. A 50-µl conidial suspension (1 × 107 conidia per ml) was applied and the holes were sealed with Parafilm. Five 'Colossal' seedlings were inoculated with sterile water. Leaf epinasty with bent petioles was observed 14 days later. Leaf wilting and necrosis similar to natural infection in the orchard were observed at 24 and 34 days after inoculation, respectively. Water-inoculated control plants showed no symptoms. Bretziella fagacearum was reisolated from symptomatic plants by surface sterilizing leaf petioles with 75% ethanol (30 s), followed by 10% (v/v) bleach (1 min), and two rinses with sterile deionized water (>1 min). Petiole pieces (~1 cm) were plated on aPDA. The pathogen was reisolated from six symptomatic plants and detected using qPCR in the remaining four seedlings. Bretziella fagacearum was not detected in control plants. The identity of the recovered fungus was confirmed following the amplification of the internal transcribed spacer (ITS) from extracted genomic DNA, as described in Chahal et al. 2022. The resulting PCR product was sequenced and assembled into a consensus sequence using Geneious Prime. The consensus sequence (accession no. OR515809) revealed 100% identity to the ex-type of B. fagacearum (KU042044). This is the first record of B. fagacearum infecting chestnut trees in Michigan. Previously, B. fagacearum has been reported infecting Chinese chestnut (C. mollissima) in Missouri (Bretz and Long, 1950). Oak wilt is widely distributed in Michigan and is the predominant disease afflicting red oaks in the Midwestern U.S. Consequently, constant vigilance and monitoring are essential in chestnut orchards to promptly detect and effectively manage potential infections.

Exploring Nutraceuticals: A Comprehensive Examination of Inception, Thematic Mapping, Evolution, Emerging Trends, and Gaps

Nutraceuticals (NCs) refer to food or dietary components that include medicinal or health-promoting properties, potentially aiding in preventing and managing specific diseases. Nutraceutical research (NCR) has made significant strides, but several gaps still need to be addressed. The study's main objective is to analyze the inception and current state of NCs, identify research gaps, and map out potential areas for future investigation in the field of NCR. The study utilized the Scopus database to gather bibliographic data through MesH-generated keywords. The search encompassed English-language original research without limitations on chronology or geography. The PRISMA methodology was employed to refine the search results. The Bibliometrix software tool, based on the R programming language, analyzes 16,030 research publications. Since 1993, NCR has experienced exponential growth of 27.27% (R2 = 0.929). Italy and the United States are the leading countries regarding publications and citations. The most prolific scholar in NCR is McClements, D.J. The research findings highlight that the antioxidant properties of plant extracts, pathophysiology of diet- and age-induced diabetes, pharmaceutical formulations, and drug delivery routes are the most cited research directions. Thematic mapping of NCR reveals a need for motor and emerging themes, with key clusters including "nutraceuticals," "antioxidant activity," and "curcumin." The thematic evolution of NCR's themes experienced a turning point in 2020. As a result, trending topics in NCR include Castanea sativa, authentication, lipophilicity, bioactive compounds, molecular docking, COVID-19, autophagy, gut microbiota, and sustainability. The study helps bridge research gaps and promotes the safe and effective use of nutraceuticals for human health. It provides valuable benefits for researchers, including identifying interesting authors, popular research areas, and collaboration opportunities. Furthermore, the findings can inform decision-makers in making strategic and informed decisions regarding policy, finance, and resource allocation in the field of nutraceutical research.

Soil mycobiome and forest endophytic fungi: Is there a relationship between them?

Fungi are important ecological agents in forests that contribute to increase the resilience of the whole ecosystem against environmental challenges. Mediterranean forests rank among the habitats most threatened by climate change and the spread of pests and diseases, which ultimately lead them into a spiral of decline. As such, changes in the composition of soil and trees’ mycobiota might correlate with health status of the forest and has been scarcely addressed in Mediterranean tree species. In this work, rhizosphere and bark-wood samples from declining Spanish forests of Castanea sativa Mill. (chestnut), Quercus ilex L. (holm oak), Q. suber L. (cork oak) and Q. pyrenaica Willd. (Pyrenean oak) were compared. Fungal communities were characterised by means of ITS metabarcoding. Higher diversity in terms of richness was found in soil, with 674 genera belonging to 15 phyla in soil vs 420 genera and 6 phyla in trees. Fungal genera exclusive to declining forests’ soils and trees didn’t include pathogenic organisms, thus preventing the association of certain genera with forest decline. Alpha diversity didn’t correlate with health status or sample type either, as it only increased in soils of asymptomatic chestnuts and not in any of the other analysed tree species. Some differentially abundant genera found in asymptomatic trees, such as Metarhizium, Aspergillus, Russula, Chaetomium, Mortierella or Cladophialophora, may be related to the biological control of decline-contributing pathogens. Finally, no relationship was found between health status and the primary lifestyles of fungi in soil and bark, which can be interpreted as a sign of resilience against adversities following cross-talk between soil and plant fungal communities.

85 years counteracting an invasion: chestnut ecosystems and landscapes survival against ink disease

A retrospective examination of early pest and disease outbreaks, such as ink disease, offers new insights into their impact on ecosystems and landscapes. Ink disease, caused by Phytophthora spp., is one of the most destructive diseases affecting Castanea sativa Mill. It first appeared in Europe in the early 18th century, with the initial recorded case in Italy (Piedmont) dating back to 1845. However, its spread instilled significant concerns in several chestnut-growing regions primarily devoted to fruit production. In 1938, a comprehensive assessment of Phytophthora xcambivora outbreaks was conducted in the Bolognese Apennines (Italy), providing a detailed overview of chestnut cultivation status. Thirty-six disease foci were documented, and laboratory tests confirmed the presence of ink disease. To understand the disease’s impact on chestnut ecosystem and landscape over the past 85 years, the 1938 sites were revisited to assess chestnut persistence and phytosanitary status, with Phytophthora species detected using isolation and molecular techniques. Monitoring data revealed that C. sativa still thrives in all but one site, with its wood seemingly able to coexist in dynamic equilibrium with the disease. While P. xcambivora was still detected in several foci, the extent of damage appeared limited. The potential for natural control, likely influenced by the complexity of soil biota, along with the natural spread of hypovirulence in chestnut blight and biological control of the Asian chestnut gall wasp, could explain the continued presence of chestnut in the investigated area and potentially throughout the Italian chestnut range, despite nearly two centuries of ink disease prevalence. Nevertheless, ongoing monitoring is essential to dynamically comprehend the factors at play and their efficacy, particularly in the context of climate change and the possible spread of other Phytophthora species. The survival of chestnut ecosystems amidst ink disease underscores the preservation of the economic, ecological, and landscape values associated with these woodlands.

Effect of climate and wood type on elastic modulus of heat-treated wood and its optimization by the Taguchi method

Wood, as the oldest building material, provides some of the basic needs of human beings, including shelter and protection. Wood is used in exterior cladding, carrier systems, joinery, ceiling-floor coverings, windows, doors, and furniture production. When wooden material is exposed to external weather conditions, due to its hygroscopic structure, its physical and mechanical properties deteriorate from exposure to moisture, temperature, and biological organisms. The bending modulus of elasticity of Scots pine (Pinus sylvestris L.), oak (Quercus petraea L.), and chestnut (Castanea sativa M.) wood that was tannin-impregnated and heat-treated at 160 °C, was investigated using Taguchi L9 (33). The sequence was optimized. After heat treatment, the carrier elements were subjected to artificial climate conditions. In the optimization of the data obtained, it was understood that the highest impact factor was the tree type. In contrast, the climate on the elastic modulus was the lowest impact factor. In Taguchi analysis, a mathematical prediction model was created using actual and predicted data using the S/N ratio’s biggest-best equation. The R2 of the model can be predicted with an accuracy rate of 98.6%.

First description of adenosine production by Gnomoniopsis smithogilvyi, causal agent of chestnut brown rot

Gnomoniopsis smithogilvyi (Gnomoniaceae, Diaporthales) is the main causal agent of chestnut brown rot on sweet chestnut worldwide. The rotting of nuts leads to alterations in the organoleptic qualities and decreased fruit production, resulting in significant economic losses. In 2021, there was an important outbreak of chestnut rot in southern Galicia (Spanish northwest). The profile of secondary metabolites from G. smithogilvyi was studied, especially to determine its capability for producing mycotoxins, as happens with other rotting fungi, due to the possible consequences on the safety of chestnut consumption. Secondary metabolites produced by isolates of G. smithogilvyi growing in potato dextrose agar (PDA) medium were identified using liquid chromatography coupled with high-resolution mass spectrometry. Three metabolites with interesting pharmacological and phyto-toxicological properties were identified based on their exact mass and fragmentation patterns, namely adenosine, oxasetin, and phytosphingosine. The capacity of G. smithogilvyi to produce adenosine in PDA cultures was assessed, finding concentrations ranging from 176 to 834 µg/kg. Similarly, the production of mycotoxins was ruled out, indicating that the consumption of chestnuts with necrotic lesions does not pose a health risk to the consumer in terms of mycotoxins.

Beneficial Effects of Castanea sativa Wood Extract on the Human Body and Possible Food and Pharmaceutical Applications.

The aim of this review was to investigate the potential use of Castanea sativa wood extract as a food supplement and to evaluate its beneficial properties for human health. The results of the limited amount of studies suggest promising properties, including potential anti-inflammatory effects. The literature indicates that the extract, which is rich in bioactive compounds such as tannins, offers promising therapeutic possibilities for the treatment of conditions associated with chronic inflammation. Consequently, interest in its use in food and pharmaceuticals is growing. Phytochemical studies have reported antioxidant and antimicrobial activities, and anti-inflammatory, anticancer, hypolipidemic, hypoglycemic, and neuroprotective activities. A suitable extraction method and solvent is crucial for the isolation of bioactive compounds, being green extraction technologies outstanding for the industrial recovery of chestnut wood's bioactive compounds. Nevertheless, it is important to emphasize the importance of adhering to regulatory guidelines and obtaining the necessary approvals from regulatory authorities to ensure product safety and compliance. The regulation of herbal medicinal products with proven efficacy and traditional herbal medicinal products is well defined, monitored by authorized bodies, and subject to strict control measures. It is noteworthy that medicinal products are subject to stringent quality testing to ensure safety and efficacy in use, whereas there are no comparable regulatory standards and specific labeling requirements for dietary supplements. When using herbal products, compliance with established standards in health research is essential.