Ammopiptanthus mongolicus is the only evergreen broad-leaved shrub in the desert region of Northwest China, which is one of the dominant species in the desert vegetation of the region, playing an important role in maintaining the stability of the local desert ecosystem. A. mongolicus is also very hardy and drought resistant and can survive extreme temperatures (Liu et al. 2013; Yang et al. 2022). The large-scale death of A. mongolicus could cause desertification in the region. Two months after the discovery of Fusarium verticillioides causing blight on A. mongolicus in Etuoke county, Inner Mongolia Autonomous Region in September 2023 (Yang et al. 2024), a large number of A. mongolicus plants with symptoms of blights were found in Lingwu city, Ningxia Hui Autonomous Region, China (106.442368°E, 37.734026°N) in November 2023. The incidence of diseased plants in this field was about 30%. The field symptoms in Lingwu city were similar to those observed in Etuoke county. The diseased leaves initially turned yellow, then wilted and dehisced, eventually resulting in plant death (Figure 1). The roots of the diseased plants were cut diagonally and the central cylinder showed a brown color (Figure 2). In order to investigate whether the death of A. mongolicus was caused by the same pathogen as those identified previously, 30 roots were collected from 10 diseased plants. After rinsing and surface sterilization (70% ethanol for 3 min and 2.5% NaClO for 5 min, rinsed 3 times with sterile distilled water), diseased tissues (10×10 mm) were placed on potato dextrose agar (PDA) (3 pieces per plate) and incubated from 3 to 5 days at 25°C. The strain AmP5 was isolated and used for further study. After 3 days on PDA medium, fungal colonies were white to milky, the undersides of the cultures were yellowish to orange-brown (Figure 3). After 7 days on synthetic nutrient-poor agar (SNA), microconidia were ovoidal or with a rounded apex and truncate base, 10.5 ± 1.5 μm × 1.6 ± 0.2 μm (×400). The macroconidia were slightly curved or arcuate, 40.5 ± 3.5 μm × 5 ± 0.5 μm (×400) (Figure 4) (Šišić et al. 2018). The pathogen was confirmed to be Neocosmospora pisi by multigene phylogenetic analysis of TEF, RPB1 and RPB2 genes using primers EF1/EF2, F5/G2R and 5F2/11AR, respectively (O\'Donnell et al. 2022). The sequences of PCR products were deposited in GenBank with accession numbers OR944631 (RPB1), OR988086 (TEF) and OR988087 (RPB2), respectively. The results of pairwise alignment in Fusarioid-ID database (Crous et al. 2021) showed 99.84% similarity and 83.96% overlap of the EF1-α sequence to the corresponding sequence LR583636 of ex-epitype CBS 123669 of Neocosmospora pisi (syn. Fusarium solani f. sp. pisi), 99.72% similarity and 85.66% overlap of the RPB1 sequence to the corresponding sequence MW834242 of ex-epitype CBS 123669 of N. pisi, and 99.47% similarity and 78.26% overlap of RPB2 sequence to the corresponding sequence LR583862 of ex-epitype CBS 123669 of N. pisi. Moreover, the result of polyphasic identification in the Fusarioid-ID database also showed EF1-a, RPB1, and RPB2 sequences had 99.15% similarity to the corresponding sequences of CBS 1233669. The pathogenicity of AmP5 was tested on potted 64 days old seedlings A. mongolicus plants. The roots of 3 seedlings were inoculated with conidial suspension (1×106 /ml), and another 3 used as controls were inoculated with sterile water, by gently peeling off the soil around the roots during inoculation, and pouring the conidial suspension around the roots (10 ml/seedling). All plants were placed in a growth chamber at 18-25℃ (10 h light; 14 h dark). After incubation for 3-5 days, the symptoms similar to those observed in the field (Figure 5), including brown rot of steles (Figure 6), developed on plants inoculated with conidial suspension, whereas no symptoms were observed on the control plants. The same pathogen was reisolated from inoculated roots and confirmed as N. pisi based on morphological and molecular analyses (TEF, RPB1 and RPB2). To our knowledge, this is the first report of blight on A. mongolicus caused by N. pisi in China. This study also indicates that blight on A. mongolicus can be caused by different fungal pathogens. Blight caused by different pathogens may have different in terms of control measures and pathogenic mechanisms, so the study of blight caused by different pathogens is of profound value.

Phoenix dactylifera L. is an economically and aesthetically important tree in the southwestern US. Approximately 4900 ha of dates are commercially grown for its edible fruit in the US, including about 1600 ha in the Yuma area and the Hyder Valley of Arizona (USDA, 2023). In October 2022, a severe rot was observed on three date palms in the Phoenix Metropolitan area. Early symptoms were brown spots that turned to a black scorch appearance extending along the leaf base and rachis, leading to the lower fronds\' wilting, drying, and folding. As the disease progressed upwards, the terminal bud became necrotic and eventually collapsed. Isolation from the necrotic leaf lesions on a potato dextrose agar (PDA) consistently yielded a fast-growing fungus that was initially white with abundant fluffy aerial mycelium, which gradually turned dark olivaceous after growing at 22-25oC under 12 h light for a week. Pycnidial conidiomata formed on pine needles in a water agar were black and globose. Conidiogenous cells were hyaline and cylindrical. The conidia exhibited a thick-walled, ovoid to ellipsoid morphology, initially appearing hyaline and aseptate and transitioned to 1-septate with a dark brown, striated appearance, measuring 19.6 to 23.0 μm x 10.3 to 12.2 µm (n = 20). For molecular identification, genomic DNA was extracted from the mycelia of two isolates. Partial DNA sequences of the internal transcribed spacer (ITS) region of rDNA and β-tubulin (TUB) gene were amplified and sequenced using primers ITS5/ITS4 (White et al. 1990) and Bt2a/Bt2b (Glass and Donaldson 1995). The resulting sequences of ITS (PP346666) and TUB (PP372690) were deposited in the GenBank. A BLASTn search of ITS and TUB sequences revealed a 99 to 100% similarity with the sequences (JX456475, KF766198, and OK338070) of Neodeightonia phoenicum strains causing palm rot in Greece (Ligoxigakis et al. 2013), leaf spot on pygmy date palm in China (Zhang and Song 2022), and an ex-type CBS 122528 culture. Based on these morphological and molecular data, the fungus was identified as N. phoenicum. A pathogenicity test was conducted twice in a greenhouse (daily temperatures:18 ~ 30 oC, relative humidity: 45% ~ 95%) on 4 healthy 1-year-old date palm plants. The petioles of 3 older leaves per plant were wounded by pricking the epidermis of the leaf with a needle (ca 20 pricks per petiole) and inoculated with agar discs from a 4-day-old PDA culture of the fungus. The control consisted of 4 mock-inoculated plants by placing plain PDA on the wounds of leaf petioles. Five weeks after inoculation, all the inoculated leaves showed symptoms of black scorch, petiole rot, and leaf necrosis, which were the same as those symptoms observed on the original diseased trees, while the controls did not show any symptoms. The fungus was re-isolated and confirmed as N. phoenicum by morphology. N. phoenicum has been reported to cause leaf spot, shoots blights, stalk and root rots as well as black scorch on different palm species all over the world. However, to our knowledge, this is the first report of N. phoenicum causing black scorch and rot disease in Arizona. The possible spread of N. phoenicum could have a significant economic impact and requires immediate attention through suitable disease management initiatives.

Bletilla striata (Thunb. ex A. Murray) Rchb (known as baiji in Chinese), a herbal plant distributed mainly in China, has become a focus of scientific attention recently due to its medicinal value (He et al. 2017). In May 2023, blight symptoms on leaves and stems were observed approximately 60% of Bletilla striata in Hangzhou, Zhejiang, China (29.80° N, 119.67° E). Brown spots initially appear on the infected leaves, which gradually decay as the spots expand. The wilting is accompanied with fading and yellowing, and eventually leading to defoliation. The infected stem initially appears brown spots, which gradually decay as the spots expand, resulting in the death of the whole plant, affecting the yield and quality of the herbs ultimately. To isolate the pathogen, small symptomatic leaves and stems (5×5 mm) were surface-disinfected with 75% ethanol for 30 s and 1% NaClO for 2 min, then rinsed in distilled water 3 times. Subsequently, the disinfected tissues were placed on PDA and incubated at 27 ℃ for 3 days. A total of 8 fungal isolates with similar morphological characteristics were obtained. The colony by single-spore purification was light purple to dark purple with abundant aerial mycelium. Macroconidia were relatively slender with a curve, mainly three to five septate and measuring 24.34 to 54.64 μm (average 40.29 μm) × 3.59 to 5.45 μm (average 4.49 μm) (n=30). Microconidia appeared obovoid to pyriform, with sizes of 5.31 to 8.43 μm (average 7.12 μm) × 2.30 to 4.29 μm (average 3.22 μm) (n=30). The morphological characteristics were consistent with Fusarium annulatum (Yilmaz et al. 2021). To further confirm the isolate\'s identification, the genomic DNA of isolates were extracted and identified by phylogenetic analyses of multilocus sequences of the RNA polymerase largest subunit (rpb1, primers Fa and G2R), RNA polymerase second largest subunit (rpb2, primers 7cf and 11ar) and the translation elongation factor 1-alpha (tef1, primers EF1 and EF2) (O\'Donnell et al. 2022). The sequences were deposited in GenBank (rpb1: OR493933, OR493934, OR753402; rpb2: OR753398, OR753399, OR753400; tef1: OR493935, OR493936, OR753401). BLAST searches of the rpb1, rpb2, and tef1 sequences revealed 99.83% (1775/1778 nt), 99.79% (957/959 nt), and 98.98% (678/685 nt) homology with those of Fusarium annulatum CBS:258.54 from New Caledonia (rpb1: MT010944; rpb2: MT010983; tef1: MT010994). To confirm pathogenicity, one-year-old B. striata leaves and stems were disinfected with 75% ethanol, wounded with a sterile syringe on 3 healthy leaves and stems, inoculated with 5 × 5 mm mycelial discs of strain BJ-L1 and BJ-S1, respectively. And the control were treated similarly except that they were inoculated with PDA discs. The experiment was replicated 3 times. After 5 days, all inoculated leaves and stems showed similar symptoms to those initially observed on infected plants. The same pathogen was re-isolated and identified by morphological characterization and molecular analysis, confirming Koch\'s postulates. Thus, the pathogen causing blight of B. striata was determined to be F. annulatum. To our knowledge, this is the first report of F. annulatum causing blight on B. striata in China. F. annulatum has a wide range of hosts and has been reported to infect a wide range of crops, fruits and vegetables (Bacon et al. 1991). This study provides the basis for further research on this disease and is important for the management of this disease and the improvement of the economic benefits of B. striata.

Ammopiptanthus mongolicus is the only evergreen broadleaf shrub and constructive species in the northwest desert of China (Hu et al. 2021). It also is listed as one of the national second-class endangered plants. Ammopiptanthus mongolicus has a good effect of water conservation, windbreak and sand fixation because its deep root system (Zhou et al. 2012; Dong et al. 2023). A large number of dead plants of Ammopiptanthus mongolicus were found in Etuoke county, Inner Mongolia Autonomous Region, China (40°4\'28″-40°4\'34″ N, 106°53\'5″-106°53\'31″ E). In September 2023, the investigation and research in the region found that the incidence of diseased plants in this field was about 30%, and for individual plant, the incidence of diseased branches was about 60%. The leaves of diseased branches initially became from green to yellow and then wilt and fall. Eventually the plant dies. (Figure 1). The miter cut of the root showed that the root steles of diseased plants had obvious black and brown color (Figure 2). For isolation, the 30 tissue blocks (10×10 mm) of from 10 symptomatic roots diseased were surface sterilized with 70% ethanol for 3 minutes and sodium hypochlorite (2.5% available chlorine) for 5 minutes, and rinsed three times with sterilized distilled water. Then, these tissue blocks were placed on potato dextrose agar (PDA) medium, and incubated from 3 to 5 days at 25°C. After 3 days on PDA, the surface of the colony was rough, the color were white-pink at the beginning, and deep purple pigment were produced in the later stage, making the colony bluish-purple to gray-purple, their undersides were bluish-purple. Mycelia were white. After 7 days on SNA, Microconidia were typical of the clavicular type, 8.5 ± 2.5 μm × 2.3 ± 0.2 μm(×400). Microconidia were usually very long conidial chains, sometimes the spore chain collapses and the conidia clump together to form an approximate pseudocephaly. The macroconidia were slender and long, slightly falcate or straight, 42.8 ± 3.4 μm × 3.8 ± 0.7 μm(×400) (Figure 4). Species identity was confirmed by sequencing the EF1-α gene (EF1 and EF2 primers)(O\'Donnell et al. 1998), RPB1 (F5 and G2R primers)(O\'Donnell et al. 2022) and RPB2 (5F2 and 11AR)(O\'Donnell et al. 2022). The amplified sequences of a representative isolate (AmP10) have deposited in GenBank with accession number OR594338 (EF1-α), OR841329 (RPB1) and OR841331 (RPB2). Thee results of pairwise alignment in Fusarioid-ID datebase(Crous et al. 2021) showed that EF1-α sequence was 99.54% similarity and 89.96% overlap to the corresponding sequence KF499582 of ex-epitype CBS 218.76 of Fusarium verticillioides, Fusarium fujikuroi species complex (FFSC, previously GFSC) (Lecellier et al. 2014), RPB1 sequence was 100% similarity and 100% overlap to the corresponding sequence MW402638 of ex-epitype CBS 218.76 of Fusarium verticillioides, Fusarium fujikuroi species complex (FFSC, previously GFSC) (Yilmaz et al. 2021), RPB2 sequence was 99.94% similarity and 87.83% overlap to the corresponding sequence MW928835 of ex-epitype CBS 218.76 of Fusarium verticillioides, Fusarium fujikuroi species complex (FFSC, previously GFSC) (Crous et al. 2021). Moreover, the result of polyphasic identification in Fusarioid-ID datebase also showed EF1-α, RPB1 and RPB2 sequences were 100% similarity to the corresponding sequences of ex-epitype CBS 218.76 of Fusarium verticillioides, Fusarium fujikuroi species complex (FFSC, previously GFSC). To test the pathogenicity, the healthy green seedlings (64 days old) were planted into plastic pots containing sterilized soil in the greenhouse after the seeds of Ammopiptanthus mongolicus were surface sterilized with 70% ethanol for 3 minutes and 2.5% sodium hypochlorite for 3 minutes. The roots of 3 seedlings were inoculated with 1×106 /ml of the conidial suspension, and another 3 used as controls with inoculated sterile water. Then, all pots were placed in a greenhouse maintained at 18°C to 25°C. After incubation for 3-5 days, the typical symptoms similar to the symptoms in the field (Figure 5), brown root steles (Figure 6), developed on the plants inoculated with conidial suspension, whereas no symptoms were observed on the control plants. The same pathogen was consistently reisolated from the inoculated roots and confirmed as Fusarium verticillioides based on morphological and molecular analyses. To our knowledge, this is the first report of Fusarium verticillioides on Ammopiptanthus mongolicus in China. This study provides a basis for identifying pathogens causing blight on Ammopiptanthus mongolicus and managing the disease.

Arthrinium phaeospermum is the major pathogen responsible for the significant stem disease \"blight\" in B. pervariabilis × D. grandis. The interacting proteins of the key pathogenic factor ApCtf1β, BDUbc and BDSKL1, have previously been obtained by two-hybrid, BiFC, GST pull-down yeast assays. However, the functions of these interacting proteins remain unknown. This study successfully obtained transgenic plants overexpressing BDUbc, BDSKL1, and BDUbc + BDSKL1 via Agrobacterium-mediated gene overexpression. qRT-PCR analysis revealed significantly increased expression levels of BDUbc and BDSKL1 in the transgenic plants. After infection with the pathogenic spore suspension, the disease incidence and severity index significantly decreased across all three transgenic plants, accompanied by a marked increase in defense enzyme levels. Notably, the co-transformed plant, OE-BDUbc + BDSKL1, demonstrated the lowest disease incidence and severity index among the transgenic variants. These results not only indicate that BDUbc and BDSKL1 are disease-resistant genes, but also that these two genes may exhibit a synergistic enhancement effect, which further improves the resistance to blight in Bambusa pervariabilis × Dendrocalamopsis grandis.

Foliar fungal blast and bacterial leaf blight have significant impacts on rice production, and their management through host resistance and agrochemicals has proven inadequate. To achieve their sustainable management, innovative approaches like leveraging the foliar microbiome, which collaborates with plants and competes against pathogens, are essential. In our study, we isolated three Pantoea strains (P. agglomerans Os-Ep-PPA-1b, P. vagans Os-Ep-PPA-3b, and P. deleyi Os-Ep-VPA-9a) from the rice phylloplane. These isolates exhibited antimicrobial action through their metabolome and volatilome, while also promoting rice growth. Our analysis, using Gas Chromatography-Mass Spectrometry (GC-MS), revealed the presence of various antimicrobial compounds such as esters and fatty acids produced by these Pantoea isolates. Inoculating rice seedlings with P. agglomerans and P. vagans led to increased root and shoot growth. Additionally, bacterized seedlings displayed enhanced immunocompetence, as evidenced by upregulated expressions of defense genes (OsEDS1, OsFLS2, OsPDF2.2, OsACO4, OsICS OsPR1a, OsNPR1.3, OsPAD4, OsCERK1.1), along with heightened activities of defense enzymes like Polyphenol Oxidase and Peroxidase. These plants also exhibited elevated levels of total phenols. In field trials, the Pantoea isolates contributed to improved plant growth, exemplified by increased flag-leaf length, panicle number, and grains per panicle, while simultaneously reducing the incidence of chaffy grains. Hypersensitivity assays performed on a model plant, tobacco, confirmed the non-pathogenic nature of these Pantoea isolates. In summary, our study underscores the potential of Pantoea bacteria in combatting rice foliar diseases. Coupled with their remarkable growth-promoting and biostimulant capabilities, these findings position Pantoea as promising agents for enhancing rice cultivation.

The genus Taxus is the natural material of the anticancer drug paclitaxel (Xiong et al. 2021). Harvesting sources of paclitaxel from the wild has greatly decreased the population of these trees. One of the taxus species, Taxus × media Rehder, a natural hybrid of taxus trees, has a higher paclitaxel content (Zhou et al. 2019). It has been introduced and cultivated in Sichuan, Chongqing, Yunnan, Zhejiang, Jiangxi, and other places in China. In 2021, approximately 20% of T. media (an average 30% of the affected area per tree) showed obvious shoot and leaf blight symptoms in a plantation of taxus trees (about 40 ha of the planting area), located in Sandaoyan county, Sichuan province, China (GPS, 103°94\'60″N, 30°84\'97″E). Initially, brown necrotic spots appeared on shoots. Gradually, the spots increased in number, expanded to the leaf attached to the branch, and caused wilting of the shoots and leaves. To identify the pathogen, symptomatic samples were randomly collected. Lesion margins of the diseased leaves and barks were surface sterilized for 1 min in 75% ethanol, rinsed with sterile distilled water three times, dried with sterile filter paper, placed on potato dextrose agar (PDA) amended with streptomycin sulfate (50 mg/liter), and incubated at 28°C in the dark. Six purified fungal isolates were obtained. Collected isolates with similar morphology were described as Botryosphaeria spp. (Zhang et al. 2021). The colonies were initially white, gradually became dark gray with dense erial mycelium after 5 days, and formed black pycnidia (Dimensions, 121.3 to 134.6 μm, n = 5) after 16 days. Conidia were fusiform, aseptate, transparent, and thin-walled (23.6 ± 1.2 × 7.27 ± 1.3 μm, n = 50), similar to B. dothidea (Hattori et al. 2021). For pathogenicity testing, ten 2-year-old seedlings of T. media were selected. Fungal cakes of the isolate Tmsdy-2 were applied to the punctured stems of seedlings and covered with Parafilm. Pieces of sterile medium were used as controls. All the seedlings were incubated at 25 ± 2°C, 50% relative humidity, and 16 h of light in a greenhouse. Four days later, the inoculated seedlings developed brown spots and were blighted in 14 days, with symptoms similar to the original diseased plants. The controls remained healthy. The same fungus was reisolated from the infected tissues and subsequently identified by morphological characteristics and DNA sequence analysis. The pathogenicity test was repeated three times with similar results, confirming Koch\'s postulates. For molecular identification, the DNA of the isolates was extracted using a Quick-DNA Extraction Kit (Tiangen Biotech, Beijing). The ITS, LSU, SSU, TUB2, and TEF 1-α genes were amplified with the primer pairs ITS1/ITS4, LR0R/LR05, NS1/NS4 (Li et al. 2018), Bt2a/Bt2b, and EF1-728F/EF1-986R (Hattori et al. 2021), respectively. The generated sequences were deposited in GenBank with accession numbers OQ179939 (ITS), OQ179940 (LSU), OQ179942 (SSU), OQ268596 (TUB2), and OQ268597 (TEF 1-α). BLAST analyses showed >99.65% identity with previously deposited sequences of B. dothidea in GenBank. Based on the maximum likelihood method, phylogenetic analysis revealed 100% bootstrap support values with B. dothidea. The fungus was identified as B. dothidea based on morphological and multilocus phylogenetic analyses. To our knowledge, this is the first report of B. dothidea causing shoot and leaf blight of T. media in China. These results will contribute to developing control strategies for this disease.

The main objective of this study was to evaluate the ability of Trichoderma aggressivum f. europaeum, T. longibrachiatum, Paecilomyces variotii, and T. saturnisporum as biological control agents (BCAs) against diseases caused by P. capsici and P. parasitica in pepper. For this purpose, their antagonistic activities were evaluated both in vitro and in vivo. We analysed the expression patterns of five defence related genes, CaBGLU, CaRGA1, CaBPR1, CaPTI1, and CaSAR8.2, in leaves. All BCAs showed a high in vitro antagonistic activity, significantly reducing the mycelial growth of P. capsici and P. parasitica. The treatments with T. aggressivum f. europaeum, T. longibrachiatum, and P. variotii substantially reduced the severity of the disease caused by P. capsici by 54, 76, and 70%, respectively, and of the disease caused by P. parasitica by 66, 55, and 64%, respectively. T. saturnisporum had the lowest values of disease reduction. Reinoculation with the four BCAs increased the control of both plant pathogens. Markedly different expression patterns were observed in the genes CaBGLU, CaRGA1, and CaSAR8.2. Based on the results, all four BCAs under study could be used as a biological alternative to chemicals for the control of P. capsici and P. parasitica in pepper with a high success rate.

We evaluated an alternative small stem assay (AltSSA) for blight resistance in backcross hybrid chestnut trees (Castanea dentata/mollissima). Whereas standard small stem assays (SSAs) are done by inoculating small incisions in stems, in our AltSSA, 4- to 5-mm stems are cut off, and the exposed (living) stem tips are inoculated with discs of Cryphonectria parasitica inoculum and temporarily covered with plastic sleeves. Intended primarily for forward selection, this method was designed to be easy to implement, to consistently induce cankering, and to better enable seedling recovery via the development of lateral shoots from the lower stem. After 90+ days, cankers are evaluated and removed, and seedlings are prepared for out-planting. Previous results showed that AltSSAs performed at least as well as a common SSA method in distinguishing resistant and susceptible types. In this follow-up analysis of 35 lines of backcross seedlings studied in 2020 and 2021, we showed that mean orange zone canker length (OZCL) and a multifactor principal components analysis-based blight resistance index gave results consistent with predictions derived from two methods of blight resistance phenotyping and percentage of American chestnut ancestry of the parents of each line. As expected, based upon the apparent polygenic inheritance of blight resistance in backcross chestnut trees, mean OZCL of backcross families ranged from intermediate (F1 hybrid-level) to low (wild-type American chestnut-level). Consistent with prior results, canker production was near 100%, survivorship after out-planting was very high, and postinoculation stem dieback was not apparently related to the stem tip inoculations. Altogether, these results suggest that the AltSSA is a viable method for early detection of relative blight resistance in seedlings and may enable a reduction in the numbers of trees out-planted and placed under care for long-term evaluation and breeding. Thus, the AltSSA can prevent time, resources, and orchard space from being used on susceptible trees.

Seedling blight of mango (Mangifera indica L.) was observed in a commercial nursery located in Messina province (eastern Sicily, Italy) during winter of 2021. More than 30% of 3,000 seedlings, about three to six months old, of mango cv. Gomera 3 showed symptoms of basal stem blight. The symptoms started from seed, led to the decline and subsequent death of the plants. Necrotic lesions appeared at crown level two months after sowing. The stem tissues of ten symptomatic plants were cut, surface sterilized, dipped in 1.5% sodium hypochlorite for 1 min and transferred onto potato dextrose agar medium (PDA) and incubated at 25°C for four days. Approximately 60% of stem tissues developed very similar fungal colonies, resembling to Botryosphaeriaceae. A total of four representative isolates were collected through single hyphal-tip and stored at 4 °C. The internal transcriber spacer region (ITS) was amplified with primers, ITS5/ITS4 (White et al., 1990), and EF1-728F and EF1-986R (Carbone and Kohn, 1999) were used to amplify part of the translation elongation factor 1alpha gene (tef1-α), and primers Bt2a/Bt2b (Glass and Donaldson, 1995) were used for the partial β-tubulin (tub2). The obtained sequences were deposited in GenBank with accession numbers: ON911292-95 for the ITS, ON933621-24 for tef1-α and ON933625-28 for tub2.To compare the results, 50 additional sequences were selected and inserted in the alignment according to the recent literature on the Botryosphaeriaceae (Bezerra et al., 2021; Zhang et al., 2021). Maximum parsimony analysis (MP) of concatenated dataset (ITS + tef1-α + tub2) was performed in PAUP v.4.0a. Clade support was assessed by 1,000 bootstrap replicates and Botryosphaeria dothidea was used as an outgroup. Our isolates clustered within the group of Neofusicoccum parvum (71% bootstrap value) (ex-type CMW9081). Based on these results, and morphological data (50 conidia length × width average: 18.1 × 6.6, respectively) our isolates (named MC) were identified and confirmed as Neofusicoccum parvum (Pennycook & Samuels) Crous, Slippers & A.J.L. Phillips. Pathogenicity tests were also conducted on 18 mango cv. Gomera 3 seedlings. The crown roots of each seedling were mechanically wounded and a mycelial plug of the isolate MC14 was placed onto them and covered with soil. Controls (three seedlings) were inoculated with sterile PDA only. Seedlings were maintained in a growth chamber with a 12 hrs photoperiod at 25°C ± 1°C and watered regularly. After five days, stem lesions appeared externally (1.6 cm) and one month after the inoculation, all the inoculated seedlings died. However, controls did not show any obvious symptoms. Re-isolations were conducted as described above and fulfilled Koch\'s postulates confirming pathogenicity. Among the diseases affecting mango plants, Botryosphaeriaceae represent a serious threat in Sicily as reported by Aiello et al., 2022. The endophytic behaviour of Botryosphaeriaceae is well known, making them latent pathogens (Slippers and Wingfield, 2007). In Italy, N. parvum was detected in mango orchards since 2013 (Ismail et al. 2013), but symptoms of seedlings stem blight have never been reported in the nursery. In Sicily, an increase of Botryosphaeriaceae infection has been observed recently, especially in nurseries, where N. parvum has been identified as a most destructive pathogen (Aiello et al., 2020; Gusella et al., 2021). To our knowledge, this is the first report worldwide of N. parvum causing mango seedling blight. The high incidence of infected seedlings detected in this study highlights the potential risk during propagation in the nursery, representing a significant source of inoculum for the field.