Avocado (Persea americana) represents an important emerging tropical crop in Italy, especially in the southern regions. In this study, young plants of avocado showing symptoms of stem and wood lesion, and dieback, were investigated. Isolations from symptomatic tissues consistently yielded colonies of Neopestalotiopsis-like species. The characterization of representative isolates was based on the observation of morphological characters, the effect of temperature on mycelial growth rate, and on the sequencing of three different gene regions, specifically ITS, TEF1, and TUB2. Phylogenetic analyses were conducted based on maximum parsimony and maximum likelihood approaches. The results showed the presence of two species, viz. Neopestalotiopsis rosae and N. siciliana, the latter of which is here described as a new species. Pathogenicity tests were conducted using the mycelial plug technique on young potted avocado trees for both Neopestalotiopsis species. The results showed that both species were pathogenic to avocado. This study represents the first report of these two species affecting avocado and results in the description of a new species within the genus Neopestalotiopsis. Based on phylogeny, Pestalotiopsis coffeae-arabicae is combined in Neopestalotiopsis.

Passion fruit (Passiflora edulis Sims.) is an ever-increasing interest crop in Italy because it is mainly cultivated for its edible fruit and, secondly, as an ornamental evergreen climber. During the summer of 2020, two-year-old plants of purple passion fruit in one of the most important expanding production areas of Sicily (southern Italy) showed symptoms of yellowing, wilting, and vascular discoloration. Fusarium-like fungal colonies were consistently yielded from symptomatic crown and stem tissues. Five representative isolates were characterized by a morphological and molecular analysis based on a multilocus phylogeny using RNA polymerase’s second largest subunit (RPB2) and translation elongation factor 1-alpha (EF-1α) genes, as Fusarium nirenbergiae (Fusarium oxysporum species complex). Pathogenicity tests conducted on healthy 1-year-old passion fruit cuttings revealed symptoms similar to those observed in the field. To our knowledge, this is the first report of Fusarium wilt on passion fruit caused by Fusarium nirenbergiae. This report focuses on the phytopathological implications of this fungal pathogen, which may represent a future significant threat for the expanding passion fruit production in Italy and Europe.

This study represents the first survey studying the occurrence, genetic diversity, and pathogenicity of Botryosphaeriaceae species associated with symptomatic citrus species in citrus-production areas in five European countries. Based on morphological features and phylogenetic analyses of internal transcribed spacer (ITS) of nuclear ribosomal DNA (nrDNA), translation elongation factor 1-alpha (TEF1) and β-tubulin (TUB2) genes, nine species were identified as belonging to the genera Diplodia, Dothiorella, Lasiodiplodia, and Neofusicoccum. Isolates of Neofusicoccum parvum and Diplodia pseudoseriata were the most frequently detected, while Dothiorella viticola had the widest distribution, occurring in four of the five countries sampled. Representative isolates of the nine Botryosphaeriaceae species used in the pathogenicity tests caused similar symptoms to those observed in nature. Isolates assayed were all re-isolated, thereby fulfilling Koch’s postulates. Isolates of Diplodia pseudoseriata and Diplodia olivarum are recorded for the first time on citrus and all species found in our study, except N. parvum, are reported for the first time on citrus in Europe.

In the past decade Colletotrichum gloeosporioides, C. karstii, and Alternaria alternata represent emerging fungal pathogens on citrus in the Mediterranean basin. Selection of tolerant Citrus germplasm offers evaluable long-term solution and should be considered as promising alternative to limit synthetic fungicide application to manage Alternaria and Colletotrichum infections in Citrus groves. In this study, the high variability of pre-harvest disease symptoms among 37 Citrus accessions was investigated in Italy in the most representative Sicilian production districts covering 1500 ha and including 20 homogeneous areas over an eleven-year survey period (2010–2020). Early fruit drop, brown spot, and anthracnose on fruit and leaves, pre-harvest fruit drop, and twig blight and defoliation associated to Alternaria and Colletotrichum spp. were identified on oranges, mandarins, and lemons. Comprehensively, first extensive data obtained herein on field susceptibility within “Tarocco” blood orange group to above disease symptoms clearly indicate as “Tarocco Nucellare 57-1E-1,” “Tarocco Tapi,” “Tarocco Sant’Alfio,” and “Tarocco Catania” accessions should be preferred to remaining Tarocco ones. A broad degree of tolerance or susceptibility was also observed within other Citrus group as it happens for tolerant lemon “Femminello Zagara Bianca,” thus demonstrating a putative resource for further studies to employ in a breeding program for genetic improvement of Citrus.

In recent years, the cultivation of tropical fruit crops has increased in the Mediterranean basin, especially in southern Italy. In surveys conducted from 2014 to 2019 woody canker and shoot blight were observed on mango plants (cvs. Kent, Keitt, Sensation, Osteen, and Kensington Pride) and litchi plants (cvs. Way Chee and Kwai Mai Pink) cultivated in Sicily. Botryosphaeriaceae and Diaporthaceae were consistently isolated from symptomatic samples. Morphological characterization and multi-locus phylogenies using three genomic loci (a portion of translation elongation factor 1-α gene, a portion of the β-tubulin gene, and an internal transcribed spacer) identified these fungi as Neofusicoccum parvum, Lasiodiplodia theobromae, Botryosphaeria dothidea, Diaporthe foeniculina, and Diaporthe baccae on mango and Diaporthe foeniculina and Diaporthe rudis on litchi. Pathogenicity tests on healthy mango (cv. Kensington Pride) and litchi (cv. Way Chee) plants demonstrated the pathogenicity of the isolates used in the study, and Koch’s postulates were fulfilled for all pathogens. To our knowledge, this is the first report of L. theobromae, B. dothidea, and Diaporthe species on mango in Italy and the first report worldwide of woody canker and shoot blight caused by D. foeniculina and D. rudis on litchi plants.