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Monitoring surveys of Phytophthora related diseases in four forest nurseries in Italy revealed the occurrence of fourteen Phytophthora species to be associated with collar and root rot on fourteen plants typical of Mediterranean and alpine regions. In addition, a multilocus phylogeny analysis based on nuclear ITS and ß-tubulin and mitochondrial cox1 sequences, as well as micromorphological features, supported the description of a new species belonging to the phylogenetic clade 7c, Phytophthora mediterranea sp. nov. Phytophthora mediterranea was shown to be associated with collar and root rot symptoms on myrtle seedlings. Phylogenetically, P. mediterranea is closely related to P. cinnamomi but the two species differ in 87 nucleotides in the three studied DNA regions. Morphologically P. mediterranea can be easily distinguished from P. cinnamomi on the basis of its smaller sporangia, colony growth pattern and higher optimum and maximum temperature values. Data from the pathogenicity test showed that P. mediterranea has the potential to threaten the native Mediterranean maquis vegetation. Finally, the discovery of P. cinnamomi in alpine nurseries, confirms the progressive expansion of this species towards cold environments, probably driven by climate change.

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.

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.

In this study a new 20-nor-ent-pimarane, named diplopimarane, was isolated together with sphaeropsidins A (9) and C (10), and (+)-epiepoformin (11) from organic crude extracts of Diplodia quercivora, a recently described oak pathogen originally found on declining Quercus canariensis trees in Tunisia. Diplopimarane was characterized as (1S,2R)-2,8,8-trimethyl-2-vinyl-1,2,3,4,5,6,7,8-octahydrophenanthrene- 1,9,10-triol by spectroscopic, X-ray, optical, and chemical methods. It exhibited a wide range of activities including remarkable phytotoxicity on nonhost plants such as tomato cuttings, moderate antifungal activity against important plant pathogens, and moderate zootoxicity against Artemia salina. Its derivatives (2−4 and 6) were also tested for their phytotoxic and zootoxic activities. All these derivatives proved to be active against A. salina at 200 μg/mL, while 2 and 6 were also active on tomato cuttings. The other secondary metabolites (9, 10, and 11) herein reported for D. quercivora exhibited phytotoxic, antifungal, and zootoxic activity. This is the first report on the secondary metabolites secreted in vitro by this oak pathogen that could be key components of its adaptative strategies.

Studies on the taxonomy and phylogeny of Diplodia have been hampered by the lack of an ex-type culture linked to the holotype of D. mutila, which is the type of the genus. In this study a large collection of Diplodia strains, obtained from ash and other woody hosts showing V-shaped cankers and branch dieback, were identified based on morphological characters and DNA sequence data from ITS and EF1-α loci. Results of combined morphological and phylogenetic analyses showed that the Fraxinus isolates from Italy, the Netherlands, Portugal and Spain belong to three distinct species namely Diplodia fraxini, Diplodia mutila and Diplodia subglobosa sp. nov. An epitype was designated for Diplodia mutila, with associated ex-epitype cultures. The name D. fraxini is re-instated and a neotype designated. Two species, Diplodia seriata and Diplodia pseudoseriata were reported for the first time on Fraxinus spp.

In this study, a strain (BL 101) of a species of Lasiodiplodia, not yet formally described, which was isolated from declining grapevine plants showing wedge-shaped cankers, was investigated for its ability to produce in vitro bioactive secondary metabolites. From culture filtrates of this strain three jasmonic acid esters, named lasiojasmonates A–C and 16-O-acetylbotryosphaerilactones A and C were isolated together with (1R,2R)-jasmonic acid, its methyl ester, botryosphaerilactone A, (3S,4R,5R)-4-hydroxymethyl-3,5-dimethyldihydro-2-furanone and (3R,4S)-botryodiplodin. The structures of lasiojasmonates A–C were established by spectroscopic methods as (1R∗,2R∗,3′S∗,4′R∗,5′R∗)-4-hydroxymethyl-3,5-dimethyldihydro-2-furanone, (1R∗,2R∗,3′S∗,4′R∗,5′R∗,10′R∗,12′R∗,13′R∗,14′S∗) and (1R∗,2R∗,3′S∗,4′R∗,5′R∗,10′S∗,12′R∗,13′R∗,14′S∗)-4-(4-hydroxymethyl-3,5-dimethyltetrahydro-furan-2-yloxymethyl)-3,5-dimethyldihydro-2-furanones jasmonates (1, 4 and 5). The structures of 16-O-acetylbotryosphaerilactones A and C were determined by comparison of their spectral data with those of the corresponding acetyl derivatives obtained by acetylation of botryosphaerilactone A. The metabolites isolated, except 4 and 5, were tested at 1 mg/mL on leaves of grapevine cv. Cannonau and cork oak using the leaf puncture assay. They were also tested on detached grapevine leaves at 0.5 mg/mL and tomato cuttings at 0.1 mg/mL. In all phytotoxic assays only jasmonic acid was found to be active. All metabolites were inactive in the zootoxic assay at 50 μg/mL.

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 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.

The Mediterranean basin is recognized as a global biodiversity hotspot accounting for more than 25,000 plant species that represent almost 10% of the world's vascular flora. In particular, the maquis vegetation on Mediterranean islands and archipelagos constitutes an important resource of the Mediterranean plant diversity due to its high rate of endemism. Since 2009, a severe and widespread dieback and mortality of Quercus ilex trees and several other plant species of the Mediterranean maquis has been observed in the National Park of La Maddalena archipelago (northeast Sardinia, Italy). Infected plants showed severe decline symptoms and a significant reduction of natural regeneration. First studies revealed the involvement of the highly invasive wide-host range pathogen Phytophthora cinnamomi and several fungal pathogens. Subsequent detailed research led to a better understanding of these epidemics showing that multiple Phytophthora spp. were involved, some of them unknown to science. In total, nine Phytophthora species were isolated from rhizosphere soil samples collected from around symptomatic trees and shrubs including Asparagus albus, Cistus sp., Juniperus phoenicea, J. oxycedrus, Pistacia lentiscus and Rhamnus alaternus. Based on morphological characters, growth-temperature relations and sequence analysis of the ITS and cox1 gene regions, the isolates were identified as Phytophthora asparagi, P. bilorbang, P. cinnamomi, P. cryptogea, P. gonapodyides, P. melonis, P. syringae and two new Clade 6 taxa which are here described as P. crassamura sp. nov. and P. ornamentata sp. nov. Pathogenicity tests supported their possible involvement in the severe decline that is currently threatening the Mediterranean maquis vegetation in the La Maddalena archipelago. National Park of the La Maddalena archipelago; Sardinian Regional Government; Autonomous Region of Sardinia, Visiting Professor Programme at the University of Sassari, Italy info:eu-repo/semantics/publishedVersion

The presence of disinfection byproducts (DBP) in drinking water raises concerns about the safety of chlorination and is one of the problems inherent the use of surface water as a source of drinking water. In order to reduce the presence of DBP (in particular of chlorites), we evaluated the combined use of chlorine dioxide for primary disinfection and monochloramine for residual disinfection in a water purification plant and distribution system in Sardinia (Italy). The results are very encouraging. Disinfection byproducts were reduced and other parameters were found to be within the recommended standards, indicating further improvements of the purification process.