Ectomycorrhizal fungi represent a key component of forest ecosystems, contributing significantly to tree nutrition, stress tolerance, and overall ecosystem resilience. In the Mediterranean region, cork oak (Quercus suber L.) forests, have significant ecological and economic value, and their vitality strongly depends on these belowground mutualistic relationships. Although previous studies have investigated the diversity and function of ectomycorrhizal fungi, several aspects concerning their ecological dynamics remain inadequately understood, particularly in cork oak forests. This study investigates the structural and dynamics of ectomycorrhizal fungal communities in cork oak forests of Sardinia located on granitic, basaltic, and trachytic substrates and subjected to different management practices (natural, grazed, and ploughed). We assess how forest management and seasonal variability interact with lithological conditions to shape community structure and diversity. Three cork oak stands for each lithological substrate (nine in total) were selected in areas where all the three forestry managements were present. Two transects were established in each stand, and soil samples were collected during spring and autumn to assess seasonal variations in the ectomycorrhizal community. In total, 82,345 ectomycorrhizal root tips were morphologically characterized and classified in 167 morphotypes based on morpho-anatomical characteristics. From these, 120 were successfully assigned to distinct Operational Taxonomic Units (OTUs) through internal transcribed spacer (ITS) barcoding. Our results indicate that lithological substrate, management system, and sampling season significantly influence the structure and composition of ectomycorrhizal communities. Notably, ploughing caused a marked reduction in fungal richness, highlighting the sensitivity of these communities to soil disturbance.

Field surveys conducted on nine farms over a 2-year period showed the widespread presence of Phytophthora-related diseases on globe artichoke plants in the main growing area in Sardinia (Italy). Characteristic symptoms included wilting and necrosis of the outermost leaves and dark brown discoloration of stem tissues, as well as root rot. A total of 18 Phytophthora colonies belonging to three species were isolated and characterized. Based on morphological features and ITS sequence data, Phytophthora isolates were identified as P. crassamura (eight isolates) and P. cactorum (four isolates). Six isolates could not be assigned to any formally described species of Phytophthora and are therefore described here as Phytophthora marrasii sp. nov. The ITS phylogeny places P. marrasii in a terminal clade basal to the sister taxa (P. foliorum, P. hibernalis, P. lateralis, and P. ramorum) of the clade 8c. In particular, P. marrasii is phylogenetically related to P. foliorum, a species from which it differs in 62 nucleotides in the ITS region. At the same time, it can easily be distinguished morphologically from P. foliorum mainly because of the low minimum temperature for growth, the bigger and persistent non-papillate sporangia, and smaller oogonia. Pathogenicity tests confirmed that all three Phytophthora species are pathogenic on globe artichokes, which represent a new host for these pathogens.

During surveys of Phytophthora diversity in natural and semi-natural Fagaceae forests in Austria, Italy and Portugal, four new cryptic species were isolated from rhizosphere soil samples. Multigene phylogeny based on nuclear ITS, ß-tubulin and HSP90 and mitochondrial cox1 and NADH1 gene sequences demonstrated that two species, P. tyrrhenica and P. vulcanica spp. nov., belong to phylogenetic Clade 7a, while the other two species, P. castanetorum and P. tubulina spp. nov., clustered together with P. quercina forming a new clade, named here as Clade 12. All four new species are homothallic and have low optimum and maximum temperatures for growth and very slow growth rates at their respective optimum temperature. They differed from each other and from related species by a unique combination of morphological characters, cardinal temperatures, and growth rates. Pathogenicity of all Phytophthora species to the root system of their respective host species was demonstrated in soil infestation trials.

HomePlant DiseaseVol. 102, No. 1First Report of Branch Canker and Dieback Caused by Cryphonectria naterciae on Quercus suber in Algeria PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Branch Canker and Dieback Caused by Cryphonectria naterciae on Quercus suber in AlgeriaH. Smahi, L. Belhoucine-Guezouli, R. T. Bouhraoua, A. Franceschini, and B. T. LinaldedduH. Smahi, L. Belhoucine-Guezouli, R. T. Bouhraoua, A. Franceschini, and B. T. Linaldeddu†Corresponding author: B. T. Linaldeddu; E-mail: E-mail Address: [email protected]http://orcid.org/0000-0003-2428-9905AffiliationsAuthors and Affiliations H. Smahi L. Belhoucine-Guezouli R. T. Bouhraoua , Université de Tlemcen – Département des Ressources Forestières, 13000 Tlemcen, Algeria A. Franceschini , Dipartimento di Agraria, Sezione di Patologia vegetale ed Entomologia, Università degli Studi di Sassari, 07100 Sassari, Italy B. T. Linaldeddu † , Dipartimento Territorio e Sistemi Agro-Forestali, Università di Padova, 35020 Legnaro (PD), Italy. Published Online:20 Nov 2017https://doi.org/10.1094/PDIS-07-17-1130-PDNAboutSections ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Over the last few decades, severe and widespread tree decline and mortality events have been observed in all the main growing cork oak (Quercus suber L.) forests in Algeria. In winter 2016, during a study on the fungal pathogens involved in the etiology of cork oak decline, Diplodia corticola was found to be the main causal agent of branch canker and dieback. However, in addition to D. corticola, isolations from five branches showing exudation, sunken canker, and dieback symptoms from 29 trees investigated in the forest of M'sila (35°37′23″N, 0°53′00″W) yielded orange to red fungal colonies with a felty and uniform mycelium on potato dextrose agar (PDA) at 25°C. Pycnidia were produced within 4 weeks in the center of colonies maintained on the laboratory bench at room temperature under natural daylight. The hyaline, cylindrical to ellipsoid, and aseptate conidia were exuded in a yellow to orange gelatinous matrix and measured 2.7 to 5.6 × 0.9 to 2.1 μm (n = 50). All morphological characters corresponded to those reported for Cryphonectria naterciae M.H. Bragança, E. Diogo & A.J.L. Phillips by Bragança et al. (2011). Identity of isolates was confirmed by analysis of the internal transcribed spacer region (ITS1-5.8S-ITS2) of rDNA. The ITS sequences of two representative isolates (BL249 and BL250) was submitted to GenBank (accession nos. MF535393 and MF535394, respectively) and BLAST searches showed 100% identity with reference sequences of C. naterciae, including that of the ex-type culture CBS 129351 (EU442657). The pathogenicity of the two representative strains was tested by inoculating freshly cut branches of cork oak following the method used by Linaldeddu et al. (2016). Ten branches were inoculated with each representative isolate and 10 were used as controls. For each branch, a 5-mm-diameter hole was punched through the bark to the wood surface with a cork borer and replaced with a colonized agar plug of the same size taken from the margin of a colony growing actively on PDA with the aerial mycelium facing the wood. Controls were treated with uncolonized agar plugs. The branches were enclosed in transparent plastic bags for 30 days, and kept in the laboratory under natural daylight at 25°C. At the end of the experimental period, all branches inoculated with fungal mycelial plugs displayed dark brown necrotic lesions on the inner bark and vascular tissues that spread up and down from the inoculation site. The average lesion size was 4.3 ± 1.4 cm (mean ± S.D.) for the strain BL249 and 4.9 ± 0.9 cm for the strain BL250. Control branches showed a brown discoloration restricted to the inoculation site. Both strains, morphologically similar to the inoculated ones, were successfully reisolated from all inoculated branches, but none from the controls, thus fulfilling Koch's postulates. C. naterciae was first isolated from Q. suber and Castanea sativa Mill. in Portugal (Bragança et al. 2011). This is the first record of C. naterciae in Algeria and the first report of this fungus as a cork oak pathogen. Our data emphasize how the number of fungal pathogens involved in the etiology of cork oak decline is greater than previously recognized and suggest that further studies are necessary to evaluate a possible synergistic interaction.References:Bragança, H., et al. 2011. Fungal Biol. 115:852. https://doi.org/10.1016/j.funbio.2011.06.014 Crossref, ISI, Google ScholarLinaldeddu, B. T., et al. 2016. Eur. J. Plant Pathol. 146:259. https://doi.org/10.1007/s10658-016-0912-z Crossref, ISI, Google ScholarDetailsFiguresLiterature CitedRelated Vol. 102, No. 1 January 2018SubscribeISSN:0191-2917e-ISSN:1943-7692 Metrics Article History Issue Date: 20 Dec 2017Published: 20 Nov 2017First Look: 12 Sep 2017Accepted: 11 Sep 2017 Pages: 251-251 Information© 2018 The American Phytopathological SocietyCited byCryphonectria naterciaeCABI Compendium, Vol. CABI CompendiumA New Double-Stranded RNA Mycovirus in Cryphonectria naterciae Is Able to Cross the Species Barrier and Is Deleterious to a New Host14 October 2021 | Journal of Fungi, Vol. 7, No. 10Cryphonectria carpinicola sp. nov. Associated with hornbeam decline in EuropeFungal Biology, Vol. 125, No. 5Cork Oak Endophytic Fungi as Potential Biocontrol Agents against Biscogniauxia mediterranea and Diplodia corticola14 November 2020 | Journal of Fungi, Vol. 6, No. 4Comparative Genomics Analyses of Lifestyle Transitions at the Origin of an Invasive Fungal Pathogen in the Genus CryphonectriamSphere, Vol. 5, No. 5Plant Pathogenic Fungi Associated with Coraebus florentinus (Coleoptera: Buprestidae) Attacks in Declining Oak Forests6 June 2019 | Forests, Vol. 10, No. 6

In Algeria cork oak forests are irregularly distributed in the northern regions along the Tell Atlas mountain range.Over the last few decades, severe tree decline and mortality events has been observed in several of the main cork oak forests.Since there is little information about the aetiology of this decline and given the high ecological and economic importance of cork oak ecosystems, a survey was carried out in six forests, M'sila and Hafir (northwestern Algeria), and Ksar Fatma, Haddada, Aïn Zana and Oued El Hout (northeastern Algeria), to establish the fungal pathogens associated with cork oak branch diseases.Isolations from symptomatic branches of 88 declining trees yielded a total of 96 fungal isolates of which 69 belonged to three distinct genera of Botryosphaeriaceae, namely Diplodia, Dothiorella and Lasiodiplodia.On the basis of morphological features and DNA sequence data (ITS and tef1-α), five species: Diplodia corticola, D. quercivora, D. sapinea, Dothiorella iberica and Lasiodiplodia exigua were identified.The geographical distribution and occurrence of the five species differed greatly among sites.The occurrence of both known lineages of D. corticola was also recognised.Pathogenicity trials showed that all the species assayed are pathogenic on cork oak and D. corticola proved to be the most aggressive.

HomePlant DiseaseVol. 101, No. 1First Report of Diplodia corticola Causing Canker and Dieback of Quercus ilex, Q. petraea, and Q. suber in Corsica (France) PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Diplodia corticola Causing Canker and Dieback of Quercus ilex, Q. petraea, and Q. suber in Corsica (France)B. T. Linaldeddu, L. Maddau, and A. FranceschiniB. T. Linaldeddu, L. Maddau, and A. FranceschiniAffiliationsAuthors and Affiliations B. T. Linaldeddu L. Maddau A. Franceschini , Dipartimento di Agraria, Sezione di Patologia Vegetale ed Entomologia, Università degli Studi di Sassari, Viale Italia 39, 07100 Sassari, Italy. Published Online:3 Nov 2016https://doi.org/10.1094/PDIS-07-16-1076-PDNAboutSectionsSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat A survey in declining oak forests of Quercus ilex, Q. petraea, and Q. suber in Corsica (France) was carried out in October 2013. Twenty botryosphaeriaceous fungal isolates were obtained from 22 diseased trees (12 Q. suber, 5 Q. ilex, and 5 Q. petraea) showing extensive sunken cankers with wedge-shaped necroses and dieback of twigs and branches. Collar rot and trunk exudates in diseased trees were also noticed. On potato dextrose agar (PDA) at 25°C, all isolates developed white colonies with dense aerial mycelium becoming dark gray after 4 to 7 days. Pycnidia were produced within 4 weeks in half-strength PDA supplemented with autoclaved Q. ilex twigs and incubated at room temperature under natural daylight. The hyaline, cylindrical to ellipsoid, and aseptate conidia measured 24.9 to 32.3 × 11.2 to 14.6 μm (n = 50). All morphological characters matched those reported for Diplodia corticola by Alves et al. (2004). Identity of isolates was confirmed by sequencing the internal transcribed spacer (ITS) region of rDNA. BLAST searches against GenBank showed 99 to 100% identity with reference sequences of D. corticola including that of ex-type culture CBS 112549. Analysis of sequences of the translation elongation factor 1-alpha (tef1-α) region grouped the isolates into the two known evolutionary lineages of D. corticola (Linaldeddu et al. 2013) as follows: 14 isolates in lineage A (8 from Q. suber, 4 from Q. ilex, and 2 from Q. petraea) and 6 isolates in lineage B (4 from Q. suber and 2 from Q. petraea). Sequences of two representative strains, BL203 (lineage B, from Q. petraea) and BL205 (lineage A, from Q. suber) were deposited in GenBank (accession numbers: KX595185 (ITS) and KX595186 (tef1-α) for strain BL203; KX595187 (ITS) and KX595188 (tef1-α) for strain BL205). The pathogenicity of the two representative strains was tested on 3-year-old Q. suber plants. Groups of five plants were inoculated separately with each isolate, and five additional plants were used as a control. The place of the stem to be inoculated was surface-disinfected with 70% ethanol and a small piece (3 × 3 mm) of bark was removed with a flamed scalpel. An agar-mycelium plug taken from the margin of an actively growing colony on PDA was placed on the wound, covered with cotton wool soaked in sterile water, and finally wrapped in a piece of aluminum foil. A sterile PDA plug was used instead of the mycelial inoculum in control plants. Plants were kept in the laboratory at 18 to 26°C under natural daylight and watered regularly for 30 days. At the end of the experiment, all plants inoculated with the fungus wilted and showed sunken, dark brown lesions on the bark, spreading up and down from the inoculation site. The average lesion size was 6.1 ± 3.2 cm (mean ± S.D.) for strain BL203 and 6.3 ± 2.4 cm for strain BL205. Both strains were successfully recovered from all the inoculated plants. The control plants remained asymptomatic. This is the first report of D. corticola occurring in Corsica and specifically on Q. petraea. In recent years, an increase has been reported in the occurrence of D. corticola on Quercus spp. in natural areas with Mediterranean climate (Linaldeddu et al. 2009; Lynch et al. 2010). In this study, severe infections by D. corticola were detected mainly on Q. suber forests in the eastern coast of Corsica.References:Alves, A., et al. 2004. Mycologia 96:598. https://doi.org/10.2307/3762177 Crossref, ISI, Google ScholarLinaldeddu, B. T., et al. 2009. J. Plant Pathol. 91:234. ISI, Google ScholarLinaldeddu, B. T., et al. 2013. Mycologia 105:1266. https://doi.org/10.3852/12-370 Crossref, ISI, Google ScholarLynch, S. C., et al. 2010. Plant Dis. 94:1510. https://doi.org/10.1094/PDIS-04-10-0266 Link, ISI, Google ScholarDetailsFiguresLiterature CitedRelated Vol. 101, No. 1 January 2017SubscribeISSN:0191-2917e-ISSN:1943-7692 Metrics Article History Issue Date: 22 Dec 2016Published: 3 Nov 2016First Look: 11 Oct 2016Accepted: 25 Sep 2016 Pages: 256-256 Information© 2017 The American Phytopathological SocietyCited bySecondary Metabolites, including a New 5,6-Dihydropyran-2-One, Produced by the Fungus Diplodia corticola. Aphicidal Activity of the Main Metabolite, Sphaeropsidin A4 April 2022 | Molecules, Vol. 27, No. 7Diplodia corticolaCABI Compendium, Vol. CABI CompendiumStatus of Charcoal Canker on Oak Trees at a Site of Community Importance: Case Study of the Relict Castelfidardo Forest (SIC Area IT520008, Castelfidardo, AN, Italy)4 August 2021 | Forests, Vol. 12, No. 8Morphological and Phylogenetic Resolution of Diplodia corticola and D. quercivora, Emerging Canker Pathogens of Oak (Quercus spp.), in the United StatesSavannah L. Ferreira, Cameron M. Stauder, Danielle K. H. Martin, and Matt T. Kasson6 April 2021 | Plant Disease, Vol. 105, No. 5Botryosphaeriaceae species on forest trees in Portugal: diversity, distribution and pathogenicity12 September 2020 | European Journal of Plant Pathology, Vol. 158, No. 3Diversity, distribution and host association of Botryosphaeriaceae species causing oak decline across different forest ecosystems in Algeria22 September 2020 | European Journal of Plant Pathology, Vol. 158, No. 3A Richer Community of Botryosphaeriaceae Within a Less Diverse Community of Fungal Endophytes in Grapevines than in Adjacent Forest Trees Revealed by a Mixed Metabarcoding StrategyBenoit Laurent, Marylise Marchand, Emilie Chancerel, Gilles Saint-Jean, Xavier Capdevielle, Charlotte Poeydebat, Anthony Bellée, Gwenaëlle Comont, Laure Villate, and Marie-Laure Desprez-Loustau24 July 2020 | Phytobiomes Journal, Vol. 4, No. 3Full Issue PDF7 August 2020 | Phytobiomes Journal, Vol. 4, No. 3Botryosphaerialean fungi causing canker and dieback of tree hosts from Mount Yudu in China12 November 2019 | Mycological Progress, Vol. 18, No. 11Diversity and pathogenicity of Botryosphaeriaceae species on forest trees in the north of Iran8 May 2019 | European Journal of Forest Research, Vol. 138, No. 4Plant Pathogenic Fungi Associated with Coraebus florentinus (Coleoptera: Buprestidae) Attacks in Declining Oak Forests6 June 2019 | Forests, Vol. 10, No. 6Characterization and Pathogenicity of Botryosphaeriaceae Fungi Associated with Declining Urban Stands of Coast Redwood in CaliforniaSrđan G. Aćimović, Suzanne Rooney-Latham, Sebastian Albu, Donald M. Grosman, and Joseph J. Doccola14 August 2018 | Plant Disease, Vol. 102, No. 10

This paper adds new insights on ecology and micromorphology of Tuber melosporum, a rare species with smooth spores. Eight T. melosporum ascomata collected in a 50 y old Pinus halepensis and Quercus ilex plantation in Sardinia, Italy, represent the first recovery of this species outside Spain. In comparison to the T. melosporum holotype, Italian specimens revealed differences in the number of spores in asci and spore shape. We propose an emended description of Tuber to include species without spore ornamentation.

Cork oak (Quercus suber) forests are economically and culturally intertwined with the inhabitants of the Mediterranean basin and characterize its rural landscape. These forests cover over two million hectares in the western Mediterranean basin and sustain a rich biodiversity of endemisms as well as representing an important source of income derived from cork production. Currently cork oak forests are threatened by several factors including human-mediated disturbances such as poor or inappropriate management practices, adverse environmental conditions (irregular water regime with prolonged drought periods), and attacks of pathogens and pests. All these adverse factors can interact, causing a complex disease commonly known as "oak decline." Despite the numerous investigations carried out so far, decline continues to be the main pathological problem of cork oak forests because of its complex etiology and the resulting difficulties in defining suitable control strategies. An overview of the literature indicates that several pathogenic fungi and oomycota can play a primary role in the etiology of this syndrome. Therefore, the aim of this review is to analyze the recent advances achieved regarding the bio-ecology of the endemic and emerging pathogens that threaten cork oak trees with particular emphasis on the species more directly involved in oak decline. Moreover, the effect of climate change on the host-pathogen interactions, a task fundamental for making useful decisions and managing cork oak forests properly, is considered.

SummaryAn analysis of incidence of Phytophthora spp. in 732 European nurseries producing forest transplants, larger specimen trees, landscape plants and ornamentals, plus 2525 areas in which trees and shrubs were planted, is presented based on work conducted by 38 research groups in 23 European countries between 1972 and 2013. Forty‐nine Phytophthora taxa were recorded in 670 nurseries (91.5%); within these nurseries, 1614 of 1992 nursery stands (81.0%) were infested, although most affected plants appeared healthy. In forest and landscape plantings, 56 Phytophthora taxa were recovered from 1667 of 2525 tested sites (66.0%). Affected plants frequently showed symptoms such as crown thinning, chlorosis and dieback caused by extensive fine root losses and/or collar rot. Many well‐known highly damaging host–Phytophthora combinations were frequently detected but 297 and 407 new Phytophthora–host associations were also observed in nurseries and plantings, respectively. On average, 1.3 Phytophthora species/taxa per infested nursery stand and planting site were isolated. At least 47 of the 68 Phytophthora species/taxa detected in nurseries and plantings were exotic species several of which are considered well established in both nurseries and plantings in Europe. Seven known Phytophthora species/taxa were found for the first time in Europe, while 10 taxa had not been previously recorded from nurseries or plantings; in addition, 5 taxa were first detections on woody plant species. Seven Phytophthora taxa were previously unknown to science. The reasons for these failures of plant biosecurity in Europe, implications for forest and semi‐natural ecosystems and possible ways to improve biosecurity are discussed.

Severe trunk and branch diseases of hazelnut trees have recently been observed in several groves in Sardinia (Italy). Since there is little information about the aetiology of these diseases and given the high ecological and economic importance of these agro-systems, an in-depth study was carried out. From autumn 2012 to spring 2014, sixty samples of twigs and branches of hazelnut trees showing exudates and different types of canker (sunken with wedge-shaped necrotic sector, open canker and Cytospora canker) were collected in the main hazelnut growing area in the centre of the island. Based on morphology, colony appearance and DNA sequence data, seven species belonging to four genera and three families were isolated and identified. These included Diplodia sapinea, D. seriata, Dothiorella iberica, Do. parva and Do. symphoricarposicola (Botryosphaeriaceae), Gnomoniopsis smithogilvyi (Gnomoniaceae) and Anthostoma decipiens (Diatrypaceae). In addition, two new species namely Diaporthella cryptica sp. nov. and Dothiorella omnivora sp. nov. are described. Pathogenicity trials carried out on wounded hazelnut branches showed that three species, Anthostoma decipiens, Diaporthella cryptica and Diplodia seriata are aggressive pathogens on hazelnut. Results obtained have allowed us to clarify, almost a century after its first description, the aetiology of the disease known as Cytospora canker of hazelnut and to reveal the existence of three evolutionarily distinct lineages for its causal agent A. decipiens. The diversity of fungal pathogens associated with twig and branch cankers of hazelnut is greater than previously recognised and further studies are necessary to determine the exact role played by each species and their possible synergistic interaction.

The rapid growth and environmental adaptability of Eucalyptus species has favored their global cultivation for pulpwood production. On the island of Sardinia, Italy, eucalypt plantations were established in the 20th century primarily in areas reclaimed from marshland, but the trees are now grown all over the island as ornamentals or windbreaks, and for timber, pulp and honey production. In recent years, an unusual decline and mortality of unknown etiology has been observed in Eucalyptus camaldulensis (river red gum) plantations throughout the island. Given the ecological and economic importance of eucalypt ecosystems in Sardinia, a survey was carried out in 2013 to determine which insect pests and fungal pathogens are directly involved in these phenomena. Field surveys throughout the island revealed severe infestations with the red gum lerp psyllid (Glycaspis brimblecombei) at all 12 surveyed sites, with the greatest numbers of pre-imaginal stages and adults occurring between May and July. The adult population reached its peak in July, followed 2 months later by the peak population of its specific parasitoid, Psyllaephagus bliteus. Symptoms of leaf chlorosis, crown thinning, shoot and branch dieback, sunken cankers, epicormic shoots and exudations of kino gum were also observed at the 12 field sites. Symptomatic woody samples yielded fungal isolates representing three distinct families: Botryosphaeriaceae, Diaporthaceae and Valsaceae. Morphological and DNA sequence data revealed seven distinct fungal species, namely Diaporthe foeniculina, Neofusicoccum australe, N. luteum, N. mediterraneum, N. parvum, N. vitifusiforme and Valsa fabianae. Two putative new species of Cytospora were also identified. Neofusicoccum australe was the only species recovered from all 12 sites, with isolation frequencies of 51-95%. Pathogenicity trials revealed that all Neofusicoccum species except N. vitifusiforme are directly involved in the etiology of the observed decline in the E. camaldulensis population on Sardinia.

Lentisk (Pistacia lentiscus L.) is an evergreen shrub that is widespread throughout the Mediterranean region. Since spring 2012, a severe and unusual disease of unknown aetiology has been observed on lentisk in six islands of the La Maddalena archipelago (Italy). The affected plants showed leaf chlorosis, crown thinning, branch dieback and sunken cankers. When branches with sunken cankers were cross-sectioned, internal wood symptoms included characteristic V-shaped necrotic sectors. Frequently, the necrotic lesions girdled the branches resulting in death of the upper crowns. Since there is no information about the aetiology of this disease and given the high ecological importance of these natural ecosystems, from spring 2012 to summer 2014, 37 samples of twigs and branches of lentisk showing sunken cankers were collected and processed. Symptomatic woody samples yielded fungal isolates representing two distinct genera in the Botryosphaeriaceae. On the basis of morphological features and DNA sequence data three distinct species: Diplodia olivarum, Neofusicoccum cryptoaustrale and N. luteum were identified. In addition, another Diplodia species morphologically distinct from all known species was isolated. Phylogenetic analyses based on nucleotide sequences of ITS and tef1-alpha regions showed that this new Diplodia species is most closely related to D. pseudoseriata and D. alatafructa. Pathogenicity trials carried out in field conditions on asymptomatic branches of lentisk showed that all four species are aggressive pathogens on this host and therefore directly involved in the severe dieback that is currently threatening this typical shrub of the Mediterranean maquis.

The diversity of Botryosphaeriaceae species associated with “Botryosphaeria dieback” of grapevine was investigated in 18 vineyards in Sardinia, Italy. Lasiodiplodia isolates obtained from different woody hosts including holm oak, sweet orange and broom bush in Italy, Algeria and Tunisia were also characterized. Morphological and cultural characteristics as well as ITS and EF1-α sequence data were used to identify the fungal isolates. Forty-eight botryosphaeriaceous isolates were obtained from 113 symptomatic grapevine samples, from which ten species were identified. Diplodia seriata was the dominant species (25 % of isolates), followed by Neofusicoccum parvum (21.7 %). Two species, Diplodia olivarum and D. africana are reported for the first time on grapevine. In addition, two new species namely Lasiodiplodia mediterranea sp. nov. from grapevine, holm oak and sweet orange and Lasiodiplodia exigua sp. nov. from broom bush are described. In artificial inoculation experiments conducted on excised green grapevine shoots and lignified canes as well as holm oak seedlings, L. mediterranea was shown to be an aggressive pathogen.

Shoot blight was observed on Erica arborea L., in a natural growing area on Caprera Island (Italy), during 2011 and 2012. Fungal isolates obtained from 324 symptomatic shoots were identified as Neofusicoccum luteum by analysis of morphological and cultural characteristics, as well as DNA sequence data of the Internal Transcribed Spacer (ITS) of the ribosomal DNA and part of the translation Elongation Factor 1-alpha (EF-1α) gene. Pathogenicity of the fungus was verified by stem inoculation of 3-year-old seedlings of E. arborea. This is the first report of N. luteum as a pathogen of E. arborea.

The knowledge of macrofungal diversity associated with Silver Fir forests in Italy is quite scarce. Only a little information is available about macrofungal communities from some Ligurian and Tuscan Silver Fir sites. This study aims to assess the macrofungal diversity of a Silver Fir plantation in Sardinia by the application of a standardized sampling procedure. A total of 606 sporomata were collected and 52 Basidiomycota were identified. The high value of the Shannon Index indicated a considerable level of macrofungal diversity in this plantation. The results were also compared with the diversity indices obtained by a previous 3-years long sampling methodology in the same site. The comparison of the macrofungal diversity values of the Sardinian site with those of the Ligurian Silver Fir forest revealed interesting similarities among natural versus planted coniferous forests.