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Botryosphaeriaceae species are the major causal agents of walnut dieback worldwide, along with Diaporthe species. Botryosphaeria dothidea and Neofusicoccum parvum are the only two Botryosphaeriaceae species associated with this recently emergent disease in France, and little is known about their diversity, structure, origin and dispersion in French walnut orchards. A total of 381 isolates of both species were genetically typed using a sequence-based microsatellite genotyping (SSR-seq) method. This analysis revealed a low genetic diversity and a high clonality of these populations, in agreement with their clonal mode of reproduction. The genetic similarity among populations, regardless of the tissue type and the presence of symptoms, supports the hypothesis that these pathogens can move between fruits and twigs and display latent pathogen lifestyles. Contrasting genetic patterns between N. parvum populations from Californian and Spanish walnut orchards and the French ones suggested no conclusive evidence for pathogen transmission from infected materials. The high genetic similarity with French vineyards populations suggested instead putative transmission between these hosts, which was also observed with B. dothidea populations. Overall, this study provides critical insight into the epidemiology of two important pathogens involved in the emerging dieback of French walnut orchards, including their distribution, potential to mate, putative origin and disease pathways.

Tamarix and Haloxylon species are considered important trees in the desert regions. During a survey conducted on Tamarix and Haloxylon trunk diseases in Iran, numerous Botryosphaeriaceae isolates were recovered from infected wood tissues of trees showing dieback and canker symptoms. Our study aimed to identify and evaluate the pathogenicity of these isolates. Based on cultural characteristics, microscopic morphological features and phylogenetic analyses of the internal transcribed spacer (ITS) and partial large subunit (LSU) nrDNA, translation elongation factor 1α (EF-1α), and β-tubulin (BT) gene sequences combination, eight Botryosphariaceae species, including Botryosphaeria dothidea, Diplodia citricarpa, Dothiorella plurivora, Dothiorella sarmentorum, Lasiodiplodia mahajangana, Lasiodiplodia theobromae, Neofusicoccum parvum and Neoscytalidium dimidiatum, were isolated and identified from Tamarix and Haloxylon species. Botryosphaeria dothidea, Neofusicoccum parvum, Lasiodiplodia theobromae and Neoscytalidium dimidiatum were recorded on both Tamarix and Haloxylon species, while the remaining species were detected only from Tamarix or Haloxylon species. Pathogenicity tests were conducted on detached shoots of Tamarix aphylla and Haloxylon ammodendron as well as branches of both tree species under field conditions. Lasiodiplodia mahajangana was the most virulent species and caused the longest wood lesion lengths on both tree species. Most of these species are reported for the first time from their respective hosts. Our findings in this study may be able to improve the basic information on the importance of Botryosphaeriaceae family on desert trees in Iran as well as other countries. [ABSTRACT FROM AUTHOR]

Introduction: Species of Botryosphaeriaceae fungi are relevant pathogens of almond causing trunk cankers, extensive gumming, necrosis of internal tissues and plant dieback and dead, threatening almond productivity. A novel triplex quantitative real-time PCR (qPCR) assay was designed for the simultaneous detection and quantification of Neofusicoccum parvum, Botryosphaeria dothidea and the Botryosphaeriaceae family. Material and methods: The method was validated in symptomatic and asymptomatic almond, avocado, blueberry and grapevine plants and in environmental samples, such as cropping soil and rainwater and in artificially inoculated trapped spores, demonstrating the same performance on several matrices. Results and discussion: The limit of detection of the triplex qPCR was 10 fg of genomic DNA for the three fungal targets, with high correlation coefficients (R2) and amplification efficiencies between 90 and 120%. Although the triplex qPCR demonstrated to be more sensitive and accurate than the traditional plate culturing and further sequencing method, a substantial agreement (kappa index = 0.8052 ± 0.0512) was found between the two detection methods. The highly sensitive qPCR assay allows for accurate diagnosis of symptomatic plants and early detection of Botryosphaeriaceae fungi in asymptomatic plants (rootstocks and grafting scions from almond nurseries). Furthermore, the triplex qPCR successfully detected Botryosphaeriaceae fungi in environmental samples, such as cropping soils and rainwater. It was also capable of detecting as few as 10 conidia in artificially inoculated tapes. Therefore, the triplex qPCR is a valuable tool for accurate diagnosis, aiding in the implementation of suitable control measures. It enables preventive detection in asymptomatic samples, helping to avoid the introduction and spread of these pathogens in production fields. Moreover, it assists in identifying inoculum sources and quantifying inoculum levels in crop environments, contributing to a precise phytosanitary application schedule, thereby reducing production costs and preserving the environment. [ABSTRACT FROM AUTHOR]

Ficus hirta Vahl is an important medicinal and edible plant in southern China. Typical green wilting on leaves and brown necrotic spots on the stems were observed since mid-June 2022 in an F. hirta plantation in Danzhou, Hainan (China). The disease rapidly developed, causing stem withering and plant death. The disease incidence varied from 45 to 85% prevalence, and the average disease index was 47 in the period of outbreak during June to December. Relevant hypothetical fungi were isolated from naturally infected wilt tissues, and their pathogens were preliminarily confirmed to be Lasiodiplodia pseudotheobromae through hypothetical fungal culturing, morphological characteristic observations, and pathogenicity testing on F. hirta plants. The phylogenetic tree constructed based on partial ITS, translation elongation factor (TEF1-α), and the β-tubulin gene (TUB2) further confirmed the identity of the pathogen as L. pseudotheobromae. Further research on the biological characteristics of L. pseudotheobromae showed that the optimal temperature for the growth of L. pseudotheobromae was PDA medium, with a temperature of 30 °C and pH of 6. Peptone and fructose were the optimal nitrogen and carbon sources for it. In vitro efficacy testing showed that among eleven fungicides, fluazinam and prochloraz had the highest mycelial growth inhibition, with an EC50 of 0.0477 µg/mL and 0.0996 µg/mL, respectively. And the two fungicides showed significant control on the stem wilt of F. hirta in a pot. To our knowledge, this is the first comprehensive report on the pathogen identification and biological characteristics of L. pseudotheobromae infecting the stem wilt of F. hirta in China. Our results provide important information for developing effective management measures and controlling this disease. [ABSTRACT FROM AUTHOR]

Abstract Botryosphaeriaceae species are the major causal agents of walnut dieback worldwide, along with Diaporthe species. Botryosphaeria dothidea and Neofusicoccum parvum are the only two Botryosphaeriaceae species associated with this recently emergent disease in France, and little is known about their diversity, structure, origin and dispersion in French walnut orchards. A total of 381 isolates of both species were genetically typed using a sequence-based microsatellite genotyping (SSR-seq) method. This analysis revealed a low genetic diversity and a high clonality of these populations, in agreement with their clonal mode of reproduction. The genetic similarity among populations, regardless of the tissue type and the presence of symptoms, supports the hypothesis that these pathogens can move between fruits and twigs and display latent pathogen lifestyles. Contrasting genetic patterns between N. parvum populations from Californian and Spanish walnut orchards and the French ones suggested no conclusive evidence for pathogen transmission from infected materials. The high genetic similarity with French vineyards populations suggested instead putative transmission between these hosts, which was also observed with B. dothidea populations. Overall, this study provides critical insight into the epidemiology of two important pathogens involved in the emerging dieback of French walnut orchards, including their distribution, potential to mate, putative origin and disease pathways.

The fungi Botryosphaeriaceae are involved in olive declines in both the world hemispheres and in all continents where this species is cultivated. In Salento (Apulia, Italy), the Botryosphaeriaceae Neofusicoccum mediterraneum and N. stellenboschiana have been reported as the agents of a branch and twig dieback that overlaps with olive quick decline syndrome caused by Xylella fastidiosa subsp. pauca. In this study, we report the finding of Diplodia seriata, another Botryosphaeriaceae species, in Salento in Xylella fastidiosa-infected olive trees affected by symptoms of branch and twig dieback. Given that its presence was also reported in olive in the Americas and in Europe (Croatia) with different degrees of virulence, we were prompted to assess its role in the Apulian decline. We identified representative isolates based on morphological features and a multilocus phylogeny. In vitro tests showed that the optimum growth temperature of the isolates is around 25–30 °C, and that they are highly thermo-tolerant. In pathogenicity trials conducted over eleven months, D. seriata expressed a very low virulence. Nonetheless, when we imposed severe water stress before the inoculation, D. seriata significatively necrotized bark and wood in a time frame of 35 days. Moreover, the symptoms which resulted were much more severe in the trial performed in summer compared with that in autumn. In osmolyte-supplemented media with a water potential from −1 to −3 Mpa, the isolates increased or maintained their growth rate compared with non-supplemented media, and they also grew, albeit to a lesser extent, on media with a water potential as low as −7 Mpa. This suggests that olives with a low water potential, namely those subjected to drought, may offer a suitable environment for the fungus' development. The analysis of the meteorological parameters, temperatures and rainfall, in Salento in the timeframe 1989–2023, showed that this area is subjected to a progressive increase of temperature and drought during the summer. Thus, overall, D. seriata has to be considered a contributor to the manifestation of branch and twig dieback of olive in Salento. Coherently with the spiral decline concept of trees, our results suggest that heat and drought act as predisposing/inciting factors facilitating D. seriata as a contributor. The fact that several adverse factors, biotic and abiotic, are simultaneously burdening olive trees in Salento offers a cue to discuss the possible complex nature of the olive decline in Salento. [ABSTRACT FROM AUTHOR]

Dothiorella species are fungal plant pathogens associated with Botryosphaeria dieback of grapevine. Symptoms caused by these fungi on grapevines suggest possible implication of phytotoxic metabolites in the infection mechanisms. However, few studies were conducted to investigate the secondary metabolism of these fungi. In this study, 6-methylpyridione analogues were isolated and identified for the first time in liquid cultures of Dothiorella sarmentorum isolated from symptomatic grapevine in Algeria. [ABSTRACT FROM AUTHOR]

Summary. Grapevine cultivation in Mexico is important, especially in the states of Baja California and Coahuila, which are the main wine production regions in the country. Grapevine trunk diseases (GTDs) impact productivity and cause substan- tial economic losses, with Botryosphaeria dieback being one of the most destructive. This disease is caused by fungi in the Botryosphaeriaceae, including species of Botry- osphaeria, Diplodia, Lasiodiplodia, and Neofusicoccum. To date, Lasiodiplodia spp. are the primary Botryosphaeriaceae fungi reported in Mexico. The present study aimed to enhance the epidemiological knowledge of Botryosphaeriaceae in Mexican vineyards. Samples from grapevine plants exhibiting disease symptoms were collected from the states of Baja California and Coahuila. Of a total of 37 Botryosphaeriaceae isolates, six species were identified: Neofusicoccum parvum, N. australe, N. vitifusiforme, Botry- osphaeria dothidea, Diplodia corticola, and D. seriata. Neofusicoccum parvum isolates were the most virulent, but were less virulent than previously reported Lasiodiplodia spp. The optimum growth temperatures for N. parvum and B. dothidea were from 28 to 30°C, but 25°C for D. seriata, N. vitifusiforme, and N. australe isolates. Only D. seria- ta isolates recovered growth when transferred to room temperature after exposure to 37°C or 40°C. This report is the first identification of B. dothidea and N. parvum as causative agents of Botryosphaeria dieback in the vine-growing regions of Mexico. [ABSTRACT FROM AUTHOR]

Mexico ranks second in the world for Persian lime (Citrus latifolia) exports, making it the principal citrus exporter within the national citrus industry, exporting over 600,000 tons per year. However, diseases are the main factor reducing production, resulting in significant economic losses. Among these diseases, fungal diseases like dieback, caused by species of Lasiodiplodia, are an emerging issue in Persian lime. Symptoms include gummosis, twig and branch dieback, cankers, the necrosis of bark and wood, fruit mummification, and tree decline. The aim of this study was to investigate the occurrence and pathogenicity of the fungal species associated with twig and branch dieback, cankers, and decline of Persian lime trees in southern Mexico, and to elucidate the current status of the Lasiodiplodia species causing the disease in Mexico. During June, July, and August of 2023, a total of the 9229 Persian lime trees were inspected across 230 hectares of Persian lime orchards in southern Mexico, and symptoms of the disease were detected in 48.78% of the trees. Branches from 30 of these Persian lime trees were collected. Fungal isolates were obtained, resulting in a collection of 40 strains. The isolates were characterized molecularly and phylogenetically through the partial regions of four loci: the internal transcribed spacer region (ITS), the β-tubulin gene (tub2), the translation elongation factor 1-alpha gene (tef1-α), and the DNA-directed RNA polymerase II second largest subunit (rpb2). Additionally, pathogenicity was assessed, successfully completing Koch's postulates on both detached Persian lime branches and certified 18-month-old Persian lime plants. Through multilocus molecular phylogenetic identification, pathogenicity, and virulence tests, five species were identified as causal agents: L. iraniensis, L. lignicola, L. mexicanensis, L. pseudotheobromae, and L. theobromae. This study demonstrates that in southern Mexico, at least five species of the genus Lasiodiplodia are responsible for dieback in Persian lime. Additionally, this is the first report of L. lignicola and L. mexicanensis as causal agents of the disease in citrus, indicating novel host interactions between species of Lasiodiplodia and C. latifolia. [ABSTRACT FROM AUTHOR]

During 2021 and 2022, a field investigation was conducted in Istria, Croatia, searching for trees exhibiting signs of Botryosphaeria dieback. Samples of symptomatic trees were collected from 26 different locations and analysed. Isolates that morphologically corresponded to species from the Botryosphaeriaceae family were selected, and detailed morphological characterisation and molecular identification of the isolates were conducted. Based on morphological characteristics and phylogenetic analysis using the internal transcribed spacer (ITS), beta-tubulin (TUB2), and translation elongation factor 1-alpha (TEF1-α) regions, six species of fungi from the Botryosphaeriaceae family were identified: Botryosphaeria dothidea (Moug. ex Fr.) Ces. & De Not.; Diplodia mutila (Fr.) Fr.; Diplodia seriata De Not.; Dothiorella iberica A.J.L. Phillips, J. Luque & A. Alves; Dothiorella sarmentorum (Fr.) A.J.L. Phillips, Alves & Luque; and Neofusicoccum parvum (Pennycook & Samuels) Crous, Slippers & A.J.L. Phillips. This is the first report of D. mutila, Do. sarmentorum, and Do. iberica causing Botryosphaeria dieback on olive trees in Croatia, and the first study investigating the resistance of Croatian olive varieties to species from the Botryosphaeriaceae family. Pathogenicity testing of selected isolates and assessment of variety resistance were conducted on four different olive varieties, namely Buža, Istarska bjelica, Leccino, and Rosinjola, using representative isolates of the mentioned species. The most aggressive species was found to be N. parvum. Olive varieties exhibited differences in susceptibility depending on the fungus they were infected with. [ABSTRACT FROM AUTHOR]

The cultivated apple (Malus × domestica) is one of Türkiye's most important economic crops. Over the growing seasons of 2020–2022, typical symptoms of branch cankers and scaling-off of the bark on apple trees were observed in the Eğirdir district of Isparta province. Botryosphaeriaceae fungi were consistently isolated from symptomatic branches. The fungal pathogen was identified as Diplodia bulgarica based on cultural and morphological characteristics and ITS region of DNA sequence data comparisons. Pathogenicity tests were performed on detached shoots by inoculating them with mycelial plugs. Diplodia bulgarica isolates caused necrotic lesions on Scarlet Spur apple detached shoots. To aid in the development of control strategies for this fungus, nine fungicides were examined in vitro for their antifungal effects against the pathogen at different concentrations. Chlorothalonil, tebuconazole, thiophanate-methyl, and fluazinam were the most efficient fungicides, with EC50 values were <1.0 µg/mL. [ABSTRACT FROM AUTHOR]

Members of the Botryosphaeriaceae are well-known endophytes and stress-related pathogens. We recently characterised the diversity of Botryosphaeriaceae in healthy tissues of three tree species in the Anacardiaceae, namely Sclerocarya birrea, Mangifera indica and Lannea schweinfurthii. Here we ask how that diversity compares with the Botryosphaeriaceae diversity associated with dieback on those tree species. Samples were collected from agroecosystems (Tshikundamalema and Tshipise in Limpopo) and conservation areas (Nwanedi and the Mapungubwe National Park in Limpopo and the Kruger National Park in Mpumalanga) ecosystems. Species were characterised using multigene sequence data and morphological data. Diplodia allocellula, Dothiorella brevicollis, Do. viticola, Lasiodiplodia crassispora, L. mahajangana and Neofusicoccum parvum occurred on both asymptomatic and symptomatic samples. Dothiorella dulcispinea, L. gonubiensis and L. exigua, as well as a previously unknown species described here as Oblongocollomyces ednahkunjekuae sp. nov, only occurred in asymptomatic branches. An interesting aspect of the biology of O. ednahkunjekuaeae is that it appears to be adapted to higher temperatures, with an optimum growth at 30 °C, and faster growth at 35 °C than at 25 °C. Lasiodiplodia pseudotheobromae only occurred in symptomatic branches. Neofusicoccum parvum was notably absent from conservation areas, and in agroecosystem it was most common on M. indica. Only L. crassispora and L. mahajangana overlapped on all three tree species and were the dominant species associated with dieback. These results show that not all Botryosphaeriaceae occurring asymptomatically in an area contribute equally to disease development on a related group of hosts, and that environmental disturbance plays a significant role in the distribution of N. parvum. [ABSTRACT FROM AUTHOR]

Purpose: The continuing search for more efficient, low-cost enzymes for biomass hydrolysis is a crucial issue in plant biorefining. Due to their ability to secrete a broad set of plant cell-wall degrading enzymes, phytopathogenic wood-colonizing fungi depict a promising source of lignocellulolytic enzymes. However, the use of phytopathogenic fungal enzymes in plant biorefining remains poorly explored. Here, we assessed the capacity of lignocellulolytic enzymes produced by the grapevine trunk pathogen Neofusicoccum parvum in the breakdown of non-pretreated wheat straw (WS) and grapevine canes (GP) after growth on these two substrates. Methods: First, we determined the peak activity time of lignocellulases during 42 days of cultivation. In addition, transcriptomics at late growth stages was performed. Second, we evaluated the performance of secreted enzymes from the WS (WS-S) and GP (GP-S) cultures in hydrolyzing both lignocellulose substrates. Results: Most of the enzymes reached the maximum activity between 14 and 28 days post-inoculation. Enzyme assays combined with transcriptomics revealed a dynamic enzyme utilization, where (hemi-)cellulases were predominantly produced at early growth stages. Afterward, enzymes acting on more recalcitrant polymers became more prominent. The WS-S released more xylose, arabinose, and total sugars from WS (3.3, 7.4, and 4.9% yields, respectively) than GP-S, although the latter generated more glucose from GP (2.4% yield). The sugar yields produced by N. parvum enzymes, particularly on WS hydrolysis, were comparable with those reported for typical industrial-use fungi, such as Aspergillus and Trichoderma spp. Conclusion: These findings suggest that N. parvum may be a helpful source of lignocellulolytic enzymes for plant biorefining. Statement of Novelty: The efficient enzymatic conversion of lignocellulose to fermentable sugars is one of the major bottlenecks in plant biorefining. That has led to a constant search for novel lignocellulolytic enzymes. Plant pathogens represent a rich but little exploited source of cell wall-degrading enzymes. This work shows that lignocellulolytic enzymes from the fungal trunk pathogen Neofusicoccum parvum performed comparatively well in converting non-pretreated wheat straw and grapevine canes into monomeric sugars. Our results suggest that both agricultural residues can be used as a cheap carbon source for producing enzymes of interest for plant biorefining, which may contribute to their valorization, particularly for the less explored grapevine pruning residues. In addition, we described a temporal utilization of lignocellulolytic enzyme in N. parvum. Highlights: Temporal dynamics in lignocellulolytic enzyme activities from N. parvum. Up-regulation of CAZymes-coding genes after long-term in vitro cultivation. N. parvum enzymes seem promising for hydrolysis of non-pretreated lignocellulose. [ABSTRACT FROM AUTHOR]

Türkiye is a prominent contributor to pear and diverse pome fruit production. Pear fruit with unusual brown to black spots and rot symptoms observed in public marketplaces in Mardin province have raised concerns regarding postharvest fruit health. The consistent isolation of a fungus from these fruits revealed morphological features indicative of Neoscytalidium dimidiatum. Phylogenetic confirmation of its identity ensued through BLASTn searches targeting, the internal transcribed spacer (ITS) of ribosomal DNA, the partial translation elongation factor 1‐alpha gene (tef1), and the partial β‐tubulin gene (tub2). Pathogenicity evaluations were conducted on common pome fruits, namely pears, apples, and quinces, unveiling the susceptibility of all examined fruits to postharvest infection by this emergent pathogen. Furthermore, an investigation was carried out to discern the pathogen's response to varying temperature ranges on pear fruits, revealing that the most pronounced lesions occurred at 30°C, followed by 25°C, 35°C, and 20°C. Conversely, no lesion development was observed at 10°C, 15°C, or 40°C. To the best of our knowledge, this study represents the first report of N. dimidiatum as the etiological agent responsible for postharvest rot in pear fruit. The implications of these findings highlight the potential threat posed by this pathogen to pome fruits postharvest, especially in regions where cold storage facilities are not widely utilized, warranting increased vigilance and preventive measures. [ABSTRACT FROM AUTHOR]

Trunk canker poses a major threat to the production of Chinese hickory tree (Carya cathayensis Sarg.), which is primarily determined by Botryosphaeriaceae. In our previous work, we identified Botryosphaeria dothidea as the predominant pathogen of this disease. However, it is still unclear about corresponding gene families and mechanisms associated with B. dothidea's pathogenicity on Chinese hickory tree. Here, we present a comparative analysis of high-quality genome assemblies of Botryosphaeria dothidea and other isolated pathogens, showing highly syntenic relationships between B. dothidea and its closely related species and the conservative evolution of the Botryosphaeriaceae family. Higher GC contents were found in the genomes of B. dothidea and three other isolated pathogens (Botryshaeria cortices, Botryshaeria fabicerciana, and Botryshaeria qingyuanensis) compared to Macrophomina phaseolina, Neofusicoccum parvum, Diplodia corticola, and Lasiodiplodia theobromae. An investigation of genes specific to or expanded in B. dothidea revealed that one secreted glucanase, one orsellinic acid biosynthesis enzyme, and two MFS transporters positively regulated B. dothidea's pathogenicity. We also observed an overrepresentation of viral integrase like gene and heterokaryon incompatibility proteins in the B. dothidea's genome. In addition, we observed one LRR-domain-containing protein and two Sec-domain-containing proteins (Sec_1 and Sec_7) that underwent positive selection. This study will help to understand B. dothidea's pathogenicity and potential influence on the infection of Chinese hickory, which will help in the development of disease control and ensure the security of Chinese hickory production. [ABSTRACT FROM AUTHOR]

Dieback of fruiting spurs, stems and branches of walnut trees (Juglans regia L.), caused by Botryosphaeriaceae, is widespread in walnut orchards in Australia. Five species of Botryosphaeriaceae (Diplodia seriata, Dothiorella omnivora, Neofusicoccum macroclavatum, N. parvum, and Spencermartinsia viticola) were recovered from the Australian walnut orchards in a previous study, with D. seriata and N. parvum being the most prevalent. The present study evaluated inhibitory effects of ten fungicides on mycelium growth of those five species and on conidium germination of D. seriata and N. parvum. It investigated the preventative and curative efficacy of selected fungicides on disease incidence in glasshouse and field trials. In vitro experiments showed that nine of the fungicides reduced mycelium growth, and all ten inhibited conidium germination, but to varying extents. Tebuconazole, prochloraz manganese chloride, fluazinam, fludioxonil and pyraclostrobin were the most effective for inhibiting mycelium growth (EC50 < 0.14 µg a.i. mL-1), whereas pyraclostrobin, fluxapyroxad, fluopyram, penthiopyrad and tebuconazole were the most effective for inhibiting conidium germination (EC50 < 2.2 µg a.i. mL-1). In planta experiments with five fungicides confirmed that preventative treatments had greater efficacy than curative treatments. A field trial with four commercial fungicide formulations demonstrated that tebuconazole and tebuconazole + fluopyram provided protection of walnut trees for the longest period. The field trial also confirmed the efficacy of pyraclostrobin and the inhibitory effect of fluazinam. This study is the first in Australia to evaluate fungicides in different classes and with different modes of action for efficacy against Botryosphaeriaceae recovered from walnut orchards in Australia, and provides a wider selection of active ingredients for a fungicide rotation programme than that which is currently available to the Australian walnut industry. [ABSTRACT FROM AUTHOR]

Field surveys were conducted in British Columbia fruit tree growing regions to determine the incidence of dieback and to identify the main fungal species causing cankers. Fruit trees showing cankers and dieback symptoms were recorded from 94% of orchards and 5.5% of trees surveyed. Overall, higher dieback incidence was observed in cherry than apple with 33% of cherry blocks showing between 5% and 26% of trees affected. Morphological studies along with DNA sequencing of the internal transcribed spacer (ITS) including the 5.8S rDNA, and parts of the translation elongation factor 1-α (TEF1), beta-tubulin (TUB2), and actin (ACT1) genes, identified seven fungi for the first time in fruit trees in Canada, including Calosphaeria pulchella, Cytospora parasitica, Cytospora populicola, Cytospora sorbicola, Ilyonectria robusta, Nectria dematiosa, and Phaeoacremonium minimum. In addition, this study reports for the first time Diplodia mutila and Diplodia seriata from cankers in sweet cherry in Canada. The already known fungal pathogens Neofabraea perennans and Neonectria ditissima were also identified. Pathogenicity studies showed N. ditissima and C. sorbicola to cause the largest vascular lesions in apple and cherry, respectively. This study identified the main fungal pathogens causing tree fruit cankers and dieback in British Columbia providing important information for the development of effective control strategies. [ABSTRACT FROM AUTHOR]

Florida ranks among the most important citrus growing regions in the USA. The present study investigates the occurrence, diversity, and pathogenicity of fungal species associated with symptomatic sweet orange (Citrus sinensis) cv. Valencia plants and fruit. The survey was conducted on twigs and fruit collected in Southwest Florida during 2022. Based on morphological and molecular characteristics, the identified isolates belonged to the species Lasiodiplodia iraniensis, Diaporthe pseudomangiferae, and Diaporthe ueckerae. The pathogenicity of representative isolates was evaluated on citrus fruit and plants. Lasiodiplodia iraniensis was the most virulent on fruit and plants, followed by Diaporthe pseudomangiferae. Diaporthe ueckerae had the lowest virulence on fruit, and it was not pathogenic to plants. In vitro tests were performed to assess the effect of temperature on mycelial radial growth. The optimum temperature of growth ranged from 26.0 to 28.4 °C for all the evaluated species, and L. iraniensis showed the fastest mycelial growth. This study represents the first report of L. iraniensis as a causal agent of tree dieback and fruit stem-end rot on C. sinensis worldwide. Moreover, D. pseudomangiferae and D. ueckerae are reported here for the first time in association with citrus diseases worldwide. [ABSTRACT FROM AUTHOR]

This article reports the first documented case of Lasiodiplodia theobromae causing dieback on Theobroma cacao (cacao) trees in Colombia. The study observed dieback symptoms in cacao trees in four municipalities in the Arauca department. The incidence of diseased trees was higher in monocultures compared to those grown under agroforestry systems. The pathogen was isolated and identified as Lasiodiplodia theobromae through PCR and DNA sequencing. Pathogenicity tests confirmed that the pathogen caused necrotic lesions on cacao twigs and seedlings. This study provides important information about a potential threat to cacao production in Colombia. [Extracted from the article]

BACKGROUND: Botryosphaeria dieback is a canker disease caused by fungal species of the Botryosphaeriaceae family that threatens almond productivity. The most common control measure to prevent canker development is the application of fungicides which are being phased out by European Union regulations. In the present study, two sets of bacterial strains were evaluated for their antifungal activity against pathogenic Botryosphaeriaceae species through in vitro and in vivo antagonism assays. RESULTS: The rhizospheric bacteria Pseudomonas aeruginosa AC17 and Bacillus velezensis ACH16, as well as the endophytic bacteria Bacillus mobilis Sol 1–2, respectively inhibited 87, 95, and 63% of the mycelial growth of Neofusicoccum parvum, Botryosphaeria dothidea, Diplodia seriata, and Macrophomina phaseolina. Additionally, they significantly reduced the length of lesions caused by N. parvum and B. dothidea in artificially inoculated detached almond twigs. All these bacterial strains produce hydrolytic enzymes that are able to degrade the fungal cell wall. P. aeruginosa AC17 also produces toxic volatile compounds, such as hydrogen cyanide. This strain was the most effective in controlling Botryosphaeria dieback in planta under controlled conditions at a level similar to the biocontrol agent Trichoderma atroviride and standard chemical fungicide treatments. CONCLUSION: Pseudomonas aeruginosa AC17 is the best candidate to be considered as a potential biocontrol agent against Botryosphaeriaceae fungi affecting almond. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

This article reports on the first occurrence of mango dieback disease caused by the fungus Lasiodiplodia brasiliense in Côte d'Ivoire. Surveys conducted in 2020 revealed the presence of mango dieback symptoms, including leaf, twig, and branch drying, as well as tree death. Isolation and analysis of the fungus confirmed its identity as Lasiodiplodia brasiliense. The pathogenicity of the fungus was also demonstrated through a greenhouse experiment. This study highlights the need for further research to understand the variation among isolates and develop effective control strategies. The research was funded by the Partnership for Skills in Applied Sciences, Engineering, and Technology and received support from the Fondation Louis Omer DECUGIS and the Société Internationale d'Importation. [Extracted from the article]

Ficus hirta Vahl is an important medicinal and edible plant in southern China. Typical green wilting on leaves and brown necrotic spots on the stems were observed since mid-June 2022 in an F. hirta plantation in Danzhou, Hainan (China). The disease rapidly developed, causing stem withering and plant death. The disease incidence varied from 45 to 85% prevalence, and the average disease index was 47 in the period of outbreak during June to December. Relevant hypothetical fungi were isolated from naturally infected wilt tissues, and their pathogens were preliminarily confirmed to be Lasiodiplodia pseudotheobromae through hypothetical fungal culturing, morphological characteristic observations, and pathogenicity testing on F. hirta plants. The phylogenetic tree constructed based on partial ITS, translation elongation factor (TEF1-α), and the β-tubulin gene (TUB2) further confirmed the identity of the pathogen as L. pseudotheobromae. Further research on the biological characteristics of L. pseudotheobromae showed that the optimal temperature for the growth of L. pseudotheobromae was PDA medium, with a temperature of 30 °C and pH of 6. Peptone and fructose were the optimal nitrogen and carbon sources for it. In vitro efficacy testing showed that among eleven fungicides, fluazinam and prochloraz had the highest mycelial growth inhibition, with an EC50 of 0.0477 µg/mL and 0.0996 µg/mL, respectively. And the two fungicides showed significant control on the stem wilt of F. hirta in a pot. To our knowledge, this is the first comprehensive report on the pathogen identification and biological characteristics of L. pseudotheobromae infecting the stem wilt of F. hirta in China. Our results provide important information for developing effective management measures and controlling this disease.

Botryosphaeriaceae are fungi involved in the decay of various woody species, including the grapevine, leading to significant production losses. This fungal family is largely ubiquitous, and seven species of Botryosphaeriaceae have been identified in French vineyards, with variable levels of aggressiveness, both in vitro and in planta. Mycoviruses can impact the life traits of their fungal hosts, including aggressiveness, and are one of the factors influencing fungal pathogenicity. In this study, the RNA mycovirome of fifteen Botryosphaeriaceae isolates was characterized through the high-throughput sequencing of double-stranded RNA preparations from the respective samples. Eight mycoviruses were detected, including three potential novel species in the Narnaviridae family, as well as in the proposed Mycobunyaviridae and Fusagraviridae families. A large collection of Botryosphaeriaceae isolates was screened using RT-PCR assays specific for 20 Botryosphaeriaceae-infecting mycoviruses. Among the mycoviruses detected, some appeared to be specialists within a single host species, while others infected isolates belonging to multiple Botryosphaeriaceae species. This screening allowed us to conclude that one-third of the Botryosphaeriaceae isolates were infected by at least one mycovirus, and a significant proportion of isolates (43.5%) were found to be coinfected by several viruses, with very complex RNA mycoviromes for some N. parvum isolates. [ABSTRACT FROM AUTHOR]

Peach (Prunus persica L.) is one of the most important and oldest stone fruits grown in China. Even though P. persica is one of the most commonly grown stone fruits in China, little is known about the biodiversity of microfungi associated with peach branch diseases. In the present study, samples were collected from a wide range of peach growing areas in China, and fungal pathogens associated with peach branch diseases were isolated. In total, 85 isolates were obtained and further classified into nine genera and 10 species. Most of the isolates belonged to Botryosphaeriaceae (46), including Botryosphaeria, Diplodia, Neofusicoccum, Phaeobotryon, and Lasiodiplodia species; Ascochyta, Didymella, and Nothophoma species representing Didymellaceae were also identified. Herein, we introduce Ascochyta prunus and Lasiodiplodia pruni as novel species. In addition, we report the first records of Nothophoma pruni, Neofusicoccum occulatum, and Phaeobotryon rhois on peach worldwide, and Didymella glomerata, Nothophoma quercina, and Phaeoacremonium scolyti are the first records from China. This research is the first comprehensive investigation to explore the microfungi associated with peach branch disease in China. Future studies are necessary to understand the pathogenicity and disease epidemiology of these identified species. [ABSTRACT FROM AUTHOR]

Mango is affected by several fungal diseases, including dieback caused by species of the Botryosphaeriaceae family. Recently, mango dieback was reported from multiple locations in Israel. In this study, we isolated and characterized 11 representative fungal isolates belonging to Botryosphaeriaceae from symptomatic mango stems. Lasiodiplodia theobromae and Neoscytalidium dimidiatum are reported in this study as pathogens causing mango dieback in Israel, based on morphology, phylogenetic inference (using ITS and tef1-α regions) and pathogenicity assays. Representative isolates of L. theobromae and N. dimidiatum caused dieback symptoms on detached mango stems under controlled conditions and on mango trees outdoors, growing under natural conditions under shade nets. The pathogens were re-isolated from inoculated stems, fulfilling Koch’s postulates. Lasiodiplodia theobromae has not been previously reported in Israel, while N. dimidiatum has been recorded on pitahaya fruit causing internal black rot disease. In this study, we report in detail on mango dieback caused by L. theobromae and N. dimidiatum in Israel. Considering the economic impact of dieback disease on mango yield, further studies on epidemiology will assist in developing disease management strategies. [ABSTRACT FROM AUTHOR]

Lavender is an oil-bearing plant, which has long been cultivated for oil, fresh flowers, dried products, and food. Leaf blight disease was observed on 'Bandera Pink', which belongs to Lavandula stoechas in Yining County, Xinjiang Uygur Autonomous Region, China. The causal agent of this disease was isolated, and Koch's postulates were assessed to confirm its pathogenicity. The morphological characteristics of the pathogen were observed, and the LSU, ITS, tef1, and tub2 loci were combined and analyzed. Based on morphological characterization and phylogenetic analyses, the causal agent was identified as a fungal species named Dothiorella sarmentorum. Pathogenicity tests revealed that D. sarmentorum can infect seven varieties of three lavender species. This is the first report of D. sarmentorum causing lavender leaf blight. This study provides a theoretical basis for the diagnosis of disease and the monitoring of disease occurrence and epidemics. [ABSTRACT FROM AUTHOR]

Botryosphaeriaceae (Botryosphaeriales, Dothideomycetes, Ascomycota) encompasses commonly encountered opportunistic pathogens that cause stem cankers on woody plants. Lifestyles of Botryosphaeriaceae species could vary as endophytes, pathogens and saprobes and one species can have one or more lifestyles. Therefore, this family is an excellent candidate to study the relationships among lifestyles and lifestyle changes. It is postulated that this family has saprobic ancestors, and the mechanisms by which they evolved from nonpathogenic ancestors to woody pathogens remain unclear. Here, we present an analysis of 18 Botryosphaeriaceae genomes, including four newly generated high-quality genomes of Botryosphaeriaceae strains. We compared Botryosphaeriaceae genomes with phylogenetically closely related Dothideomycetes taxa including plant pathogens and saprobes which revealed significant net gene family expansion in Botryosphaeriaceae. This gene expansion is prominent in the early ancestors before the divergence of genera of Botryosphaeriaceae. This expansion affected the pathogenicity-related genes and detoxification genes. Furthermore, we analysed horizontal gene transfer, which is a mechanism of transfer to genetic material between organisms that are not in a parent–offspring relationship and identified widespread putative intra-kingdom horizontal gene transfer events in this family. Most were transferred during the evolution of ancient ancestors of Botryosphaeriaceae, before the divergence of the modern genera and were enriched in pathogenicity-related genes and detoxification genes. Furthermore, The RNA sequencing analysis of the Botryosphaeriaceae species Lasiodiplodia theobromae revealed that pathogenicity-related genes and detoxification genes, including those obtained through gene family expansion and horizontal gene transfers, were significantly induced after the infection of plant hosts rather than before infection. These insights reveal critical roles for gene family expansion and horizontal gene transfers in the evolutionary adaptation of Botryosphaeriaceae in the infection of woody plants. We postulate that the pathogenic lifestyle of Botryosphaeriaceae species evolved from saprobic or endophytic lifestyles in the early divergence of this family. However, there are few endophytic genomes available for closely related species of Botryosphaeriaceae, thus further studies are necessary to clarify the evolutionary relationships of the endophytes. [ABSTRACT FROM AUTHOR]

Recently, grapevine trunk diseases have been considered the most destructive of grapevine species in Morocco. Several damages are observed annually in vineyards by these destructive diseases in vineyards. Botryosphaeria dieback is one of the major responsible of these wasting diseases. Symptoms include sectorial and central necrosis, brown bands or cracks, discolorations and withering on the foliar surface. Botryosphaeria dieback symptomatology, associated fungi, host-pathogen interaction, and control methods are the topics of this review. [ABSTRACT FROM AUTHOR]

The emergence of new plant diseases is an increasingly important concern. Climate change is likely to be among the factors causing most of the emerging diseases endangering forest and tree heritage around the world. Such diseases may be caused by latent pathogens or microorganisms cryptically associated with plants. The shift from a non-pathogenic to a pathogenic stage may depend on physiological alterations of the host, environmental changes, and/or stress factors. In some woods of the Salento Peninsula (Apulia Region, Italy), sudden declines of holm oak plants (Quercus ilex L.) have been observed since 2016. The morphological and molecular characterization of representative fungal isolates associated with cankers and necrosis in declining plants indicated that these isolates belong to the Botryosphaeriaceae family, and the most frequent species were Diplodia corticola and Diplodia quercivora, followed by Neofusicoccum vitifusiforme. In artificially inoculated young holm oak plants, both D. corticola and D. quercivora species produced intense and severe subcortical and leaf margin necrosis. N. vitifusiforme, although less aggressive, induced the same symptoms. Our research, in addition to confirming the involvement of D. corticola in olm oak decline, represents the first report of D. quercivora as a new pathogen of Q. ilex in Italy. Furthermore, to the best of our knowledge, we also found N. vitifusiforme as a new pathogen of Q. ilex. [ABSTRACT FROM AUTHOR]

Macrophomina phaseolina is a plant pathogenic fungus that is frequently described as having a broad host range encompassing more than 500 species. We noticed that citations provided in support of this statement do not actually demonstrate such a broad host range. To elucidate the true documented host range of this fungus, we initiated a literature metaanalysis of 894 publications on M. phaseolina since 1913. We discovered that the first host range summaries did not require Koch's postulates or other experimental demonstrations of pathogenicity. Most of the available early host claims were based on tenuous associations between the fungus and symptoms, sometimes without reporting isolation or morphological examination in vitro. These statements apparently led to a pattern of increasingly exaggerated host range claims, without support from a primary reference, until the claim that M. phaseolina has 500 hosts became common in the early 2000s. At present, the scientific community typically requires Koch's postulates to characterize pathogenicity on a new host. Among all the available literature, we only found primary experimental evidence for M. phaseolina's, pathogenicity on 97 hosts; 74 hosts confirmed by Koch's postulates and 23 hosts with all steps from Koch's postulates completed except for recovery of the pathogen from symptomatic tissues. This study demonstrates how scientific concepts can change over time and necessitate changes to historic axioms. We propose that the hyperbole surrounding the host range of M. phaseolina has obscured an accurate depiction of its biology. [ABSTRACT FROM AUTHOR]

A severe dieback of flowering ash (Fraxinus ornus L.) has been observed in north-central Italy in the last decades. Symptoms include typical sunken, light-brown cankers on the stem and branches; vascular discoloration; tip and shoot dieback; and foliage necroses. The disease was more evident at the beginning of the growing season, and more severe on young regeneration. Six Botryosphaeriaceae species were consistently isolated from symptomatic plant tissues: Botryosphaeria dothidea, Diplodia fraxini, Diplodia subglobosa, Dothiorella iberica, Dothiorella omnivora and Neofusicoccum parvum. B. dothidea and D. fraxini expressed higher aggressiveness and showed a widespread incidence, being the species most frequently associated with cankers; the other four species were less virulent and more erratic, occurring mainly on succulent branch tips and foliage. Isolates were characterized using morphological and molecular approaches (colony/conidial phenotyping and rDNA-ITS genotyping). Phylogenetic analysis provided congruent phylogenies depicting the relationships of the six taxa with the most closely related conspecifics. Pathogenicity tests on 2-year-old seedlings confirmed the higher virulence of B. dothidea and D. fraxini. Extensive, multi-year field surveys at different sites supported the hypothesis that climatic vagaries, mainly heat, water and drought stresses, impaired tree health and vigor, facilitating infection and pervasive colonization by these Botryosphaeriaceae species. Environmental stressors are thus the key factor bringing the six fungal pathogens together in a multitrophic interaction with F. ornus in a novel, lethal fashion. [ABSTRACT FROM AUTHOR]

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This article reports the first occurrence of Lasiodiplodia theobromae causing leaf blight on Coffea canephora (robusta coffee) in the Philippines. The disease was observed in a coffee plantation in the Soccsksargen region, which is a major coffee production area in the country. The symptoms included brown to black necrotic lesions on the leaf margins, with a 100% incidence rate among the trees. The fungus was isolated and identified as L. theobromae based on its morphological and genetic characteristics. This finding highlights the need for management strategies to mitigate the impact of the disease on coffee production. [Extracted from the article]

The fungi Botryosphaeriaceae are involved in olive declines in both the world hemispheres and in all continents where this species is cultivated. In Salento (Apulia, Italy), the Botryosphaeriaceae Neofusicoccum mediterraneum and N. stellenboschiana have been reported as the agents of a branch and twig dieback that overlaps with olive quick decline syndrome caused by Xylella fastidiosa subsp. pauca. In this study, we report the finding of Diplodia seriata, another Botryosphaeriaceae species, in Salento in Xylella fastidiosa-infected olive trees affected by symptoms of branch and twig dieback. Given that its presence was also reported in olive in the Americas and in Europe (Croatia) with different degrees of virulence, we were prompted to assess its role in the Apulian decline. We identified representative isolates based on morphological features and a multilocus phylogeny. In vitro tests showed that the optimum growth temperature of the isolates is around 25–30 °C, and that they are highly thermo-tolerant. In pathogenicity trials conducted over eleven months, D. seriata expressed a very low virulence. Nonetheless, when we imposed severe water stress before the inoculation, D. seriata significatively necrotized bark and wood in a time frame of 35 days. Moreover, the symptoms which resulted were much more severe in the trial performed in summer compared with that in autumn. In osmolyte-supplemented media with a water potential from −1 to −3 Mpa, the isolates increased or maintained their growth rate compared with non-supplemented media, and they also grew, albeit to a lesser extent, on media with a water potential as low as −7 Mpa. This suggests that olives with a low water potential, namely those subjected to drought, may offer a suitable environment for the fungus’ development. The analysis of the meteorological parameters, temperatures and rainfall, in Salento in the timeframe 1989–2023, showed that this area is subjected to a progressive increase of temperature and drought during the summer. Thus, overall, D. seriata has to be considered a contributor to the manifestation of branch and twig dieback of olive in Salento. Coherently with the spiral decline concept of trees, our results suggest that heat and drought act as predisposing/inciting factors facilitating D. seriata as a contributor. The fact that several adverse factors, biotic and abiotic, are simultaneously burdening olive trees in Salento offers a cue to discuss the possible complex nature of the olive decline in Salento.

Mexico ranks second in the world for Persian lime (Citrus latifolia) exports, making it the principal citrus exporter within the national citrus industry, exporting over 600,000 tons per year. However, diseases are the main factor reducing production, resulting in significant economic losses. Among these diseases, fungal diseases like dieback, caused by species of Lasiodiplodia, are an emerging issue in Persian lime. Symptoms include gummosis, twig and branch dieback, cankers, the necrosis of bark and wood, fruit mummification, and tree decline. The aim of this study was to investigate the occurrence and pathogenicity of the fungal species associated with twig and branch dieback, cankers, and decline of Persian lime trees in southern Mexico, and to elucidate the current status of the Lasiodiplodia species causing the disease in Mexico. During June, July, and August of 2023, a total of the 9229 Persian lime trees were inspected across 230 hectares of Persian lime orchards in southern Mexico, and symptoms of the disease were detected in 48.78% of the trees. Branches from 30 of these Persian lime trees were collected. Fungal isolates were obtained, resulting in a collection of 40 strains. The isolates were characterized molecularly and phylogenetically through the partial regions of four loci: the internal transcribed spacer region (ITS), the β-tubulin gene (tub2), the translation elongation factor 1-alpha gene (tef1-α), and the DNA-directed RNA polymerase II second largest subunit (rpb2). Additionally, pathogenicity was assessed, successfully completing Koch’s postulates on both detached Persian lime branches and certified 18-month-old Persian lime plants. Through multilocus molecular phylogenetic identification, pathogenicity, and virulence tests, five species were identified as causal agents: L. iraniensis, L. lignicola, L. mexicanensis, L. pseudotheobromae, and L. theobromae. This study demonstrates that in southern Mexico, at least five species of the genus Lasiodiplodia are responsible for dieback in Persian lime. Additionally, this is the first report of L. lignicola and L. mexicanensis as causal agents of the disease in citrus, indicating novel host interactions between species of Lasiodiplodia and C. latifolia.

Many fungi belonging to Botryosphaeriaceae are well-known as causal agents of diseases in economically and ecologically important agricultural crops and forest trees. In Italy, the high diffusion of Botryosphaeriaceae infections observed over the last decade, has shown the importance of this group of fungi, which are becoming limiting factors for plant production in agricultural systems, nurseries and natural and urban landscapes. Global warming and stress factors such as occasional extreme climatic events can affect the susceptibility of host plants, as well as fungus behaviour, increasing the risk of future infections. Available reports of Botryosphaeriaceae in Italy have been examined, focusing on wood and fruit pathogens, resulting in a list of ten genera and 57 species. Diplodia is the most widespread genus in Italy with 76 records on 44 hosts, while at species level, Neofusicoccum parvum, Botryosphaeria dothidea and Diplodia seriata show the widest host ranges and many records. The ability of the pathogens to remain latent on asymptomatic plants, and uncontrolled trade of plant materials among countries, facilitate the dissemination and potential introduction of new Botryosphaeriaceae species. Preventive detection and adequate control strategies are always needed to limit the potential damage caused by Botryosphaeriaceae. This review had particular emphasis on host-pathogen associations, disease symptoms, geographic distribution, metabolite production, and accurate pathogen identification. [ABSTRACT FROM AUTHOR]

In recent years, an unusual decline and mortality has been observed in Paulownia plantations throughout the Marche region (Central Italy). Given the economic importance of this emerging forest crop, a study was conducted to determine which pathogens are directly involved in this syndrome. Field surveys performed in two plantations revealed the widespread occurrence of severe disease symptoms such as leaf chlorosis, crown thinning, shoot and branch dieback, sunken cankers, epicormic shoots and root rot. Disease incidence was also assessed by aerial remote sensing (RS) technologies using drones. Symptomatic samples collected from both stem and root tissues yielded fungal and fungal-like colonies representing two distinct families: Botryosphaeriaceae and Peronosporaceae. Morphological and DNA sequence data revealed five distinct species, identified as Macrophomina phaseolina and Botryosphaeria dothidea (Botryosphaeriaceae), Phytophthora pseudocryptogea, P. citrophthora and P. erythroseptica (Peronosporaceae). Given that all species are reported here for the first time on Paulownia, Koch's postulates were satisfied inoculating the three Phytophthora species and two Botryosphaeriaceae at the collar of the stem of potted 1-year-old rooted cuttings in June 2023. Thirty days after inoculation, all plants showed the same symptoms as those observed in the field. [ABSTRACT FROM AUTHOR]

Species in the Botryosphaeriaceae are common plant pathogens, endophytes, and saprobes found on a variety of mainly woody hosts. Botryosphaeriaceae is a high-profile fungal family whose genera have been subjected to continuous revisions in recent years. Surveys conducted during 2019 and 2020 on several decaying woody hosts (from dead arial twigs, branches, stems, bark, and seed pods) in China and Thailand revealed a high diversity of Botryosphaeriaceae fungi. Identification of 16 Botryosphaeriaceae isolates was carried out based on both morphological characteristics and phylogenetic analyses of combined ITS, LSU, tef1-α, and tub2 sequence data. Four novel species (Dothiorella ovata, Do. rosacearum, Do. septata, and Lasiodiplodia delonicis) and seven previously known species (Botryosphaeria fujianensis, Diplodia mutila, Di. seriata, L. crassispora, L. mahajangana, Macrophomina euphorbiicola and Sphaeropsis eucalypticola) were identified while new hosts and geographical records were reported. This study indicates that the fungal family Botryosphaeriaceae seems to be common and widespread on a broad range of hosts in China and Thailand. [ABSTRACT FROM AUTHOR]

Neoscytalidium dimidiatum, a plant- and human-associated fungus, has emerged as a substantial global ecological and agricultural threat aggravated by global warming. It inflicts various diseases, including canker, blight, dieback, leaf spot, root rot, and fruit rot, across a wide spectrum of fruit trees, field crops, shrubs, and arboreal species, with a host range spanning 46 plant families, 84 genera, and 126 species, primarily affecting eudicot angiosperms. Six genera are asymptomatic hosts. Neoscytalidium dimidiatum exhibits worldwide distribution, with the highest prevalence observed in Asia and North America, notably in Iran, Turkey, and California. Rising disease prevalence and severity, aggravated by climate change, particularly impact tropical arid places across 37 countries spanning all 7 continents. This comprehensive review encapsulates recent advancements in the understanding of N. dimidiatum, encompassing alterations in its taxonomic classification, host range, symptoms, geographic distribution, epidemiology, virulence, and strategies for effective management. This study also concentrates on comprehending the taxonomic relationships and intraspecific variations within N. dimidiatum, with a particular emphasis on N. oculus and N. hylocereum, proposing to consider these two species as synonymous with N. dimidiatum. Furthermore, this review identifies prospective research directions aimed at augmenting our fundamental understanding of host—N. dimidiatum interaction. [ABSTRACT FROM AUTHOR]

Summary: During the winter of 2022, camphor trees (Cinnamomum camphora L.) showing symptoms of canker, wood discoloration and twig dieback were detected in a nursery located in Catania province of eastern Sicily, Italy. Samples were brought to the laboratory, and isolations revealed the presence of Botryosphaeriaceae spp. in symptomatic wood tissues. Representative isolates were sub-cultured and identified by sequencing. Specifically, the three loci (ITS, tef-1α, and tub2) were amplified by conventional PCR and sequenced. Phylogenetic analysis using the Maximum parsimony approach revealed that nine isolates were strongly clustered within the clade of Neofusicoccum parvum and one isolate within the clade of N. luteum. Pathogenicity tests were conducted by inoculating stems of 1-year-old camphor trees with mycelial plugs of three representative isolates of N. luteum and N. parvum. Nine days after the inoculation, the camphor trees showed the same symptoms as those observed in the nursery. To the best of our knowledge, this is the first report worldwide of N. luteum and N. parvum causing disease in camphor tree. [ABSTRACT FROM AUTHOR]

Shoot blight and branch dieback of English walnut has been associated with a broad diversity of Botryosphaeriaceae and Diaporthe fungi worldwide. These pathogens affect both wood and fruit tissues, infecting the tree through mechanical or natural wounds. Fruit infections can play an important role in the life cycle of the disease. Thus, the effects of cultivar, and fruit maturity on English walnut fruit infection by Botryosphaeriaceae (Botryosphaeria dothidea, Neofusicoccum mediterraneum and N. parvum) and Diaporthe (Diaporthe neotheicola and Dia. rhusicola) fungi were evaluated. The infection and disease progress from inoculated attached fruits or by inoculating fruit abscission wounds was evaluated both under laboratory and field conditions. An initial experiment evaluating two inoculation methods was conducted, but there were not significant differences in disease severity between inoculations with mycelial plugs or conidial suspensions. A total of eight cultivars were selected to evaluate their susceptibility to fruit infection, with 'Chandler' being the most susceptible for all the pathogens tested compared to the other cultivars. Botryosphaeriaceae showed higher aggressiveness on fruit collected at beginning- or middle summer, while Diaporthe showed similar aggressiveness regardless of fruit maturity stage. Botryosphaeriaceae fungi were able to colonize the entire surface of the inoculated fruit, reaching the peduncle and infecting the attached shoot; while Diaporthaceae fungi were not able to colonize the surface of the inoculated fruit quickly enough to infect the attached shoot before the peduncle was naturally separated from the shoot. Finally, we demonstrated that both Botryosphaeriaceae and Diaporthe fungi can infect shoots by inoculating the natural fruit abscission wounds in the field. This study generates new insights into the influence of fruit infection leading to shoot blight and branch dieback of English walnut caused by Botryosphaeriaceae and Diaporthe fungi. [ABSTRACT FROM AUTHOR]

Xylella fastidiosa subsp. pauca (XFP), Neofusicoccum mediterraneum, N. stellenboschiana and other fungi have been found in olive groves of Salento (Apulia, Italy) that show symptoms of severe decline. XFP is well known to be the cause of olive quick decline syndrome (OQDS). It has also been assessed that Neofusicoccum spp. causes a distinct disease syndrome, namely, branch and twig dieback (BTD). All these phytopathogens incite severe symptoms that can compromise the viability of large canopy sectors or the whole tree. However, their specific symptoms are not easily distinguished, especially during the final stages of the disease when branches are definitively desiccated. By contrast, they can be differentiated during the initial phases of the infection when some facets of the diseases are typical, especially wood discoloration, incited solely by fungi. Here, we describe the typical symptomatological features of OQDS and BTD that can be observed in the field and that have been confirmed by Koch postulate experiments. Similar symptoms, caused by some abiotic adverse conditions and even by additional biotic factors, are also described. Thus, this review aims at: (i) raising the awareness that declining olive trees in Salento do not have to be linked a priori to XFP; (ii) defining the guidelines for a correct symptomatic diagnosis to orient proper laboratory analyses, which is crucial for the application of effective control measures. The possibility that bacterium and fungi could act as a polyspecies and in conjunction with predisposing abiotic stresses is also widely discussed. [ABSTRACT FROM AUTHOR]

Surveys of canker diseases in 26 walnut orchards were conducted in the southeastern Turkish provinces of Batman, Diyarbakır, and Şanlıurfa in 2020. Decline symptoms on trees were most severe in the trunks of grafted trees grown on unproductive local rootstocks with Chandler and Franquette scions throughout the surveyed areas, and samples were taken from those trees. Lasiodiplodia theobromae was identified from the cankers on the trees of the seven orchards, while Neoscytalidium dimidiatum was identified from the other 19 orchards based on morphological characteristics. DNA sequencing analysis of 10 representative isolates using the ITS1-5.8S-ITS2 (ITS), the large subunit (LSU), and the translation elongation factor 1-alpha (EF-1α) genes confirmed the identification of the causal fungi. Pathogenicity tests on 2 year-old Chandler seedlings revealed that L. theobromae and N. dimidiatum produced lesion length averages of 7–8 cm and 15–25 cm after 3 weeks of stem-inoculation, respectively. Koch's postulates were confirmed by successfully reisolating the fungi only from plants inoculated. This is the first study to document L. theobromae as the causal agent of walnut tree decline and cankers in Turkey. [ABSTRACT FROM AUTHOR]

In the light of ongoing climate change, European beech trees face a loss of vitality due to an expected increase in the frequency of droughts, exacerbated by prolonged periods of high temperatures and solar radiation. Such conditions increase the predisposition to European beech splendour beetle attacks, and trigger sunburn, fungal infections and complex diseases. As a result, European beech forests are seriously threatened by climate change. Following prolonged and repeated periods of exceptional drought since 2018, European beech decline have been observed in several regions of Germany and Europe. Vitality losses, in some cases severe, of due to the extraordinarily warm, dry summers of 2018 and 2019 have been observed and investigated in several regions of Germany. The first symptoms of vitality loss of European beech associated with severe signs of crown dieback were recorded in midsummer 2018. Mortality of branches and individual trees was often associated with sunburn, bark necrosis and bleeding spots of sap flux. The first signs of mortality were observed locally in predisposed stands in autumn 2018. The stem stability and break resistance of affected trees were significantly reduced. To elucidate the complex interactions involved, the occurrence of vitality loss of European beech and associated causative agents were examined in north-western Germany. Disease symptoms of individual trees were studied, associated fungi (endophytes, plant pathogens and saprobes) were isolated and identified. Frequent potentially severe pathogens included Neonectria coccinea, Diplodia corticola and D. mutila. The presented cases of disease were the first, where D. corticola was recorded on beech. In addition, inoculation tests were used to assess the potential roles of Botryosphaeria species in the observed symptomatology. [ABSTRACT FROM AUTHOR]

Grapevine trunk diseases (GTDs) are taking the forefront of winegrowers' concerns, as they cause considerable damage in vineyards not only quantitatively but also qualitatively. Furthermore, in the last three decades, an increasing incidence of the socioeconomic impact of these fungal pathologies has been observed. To date, no effective control strategies or curative treatments are available for these diseases that can replace the effectiveness offered by a series of chemical synthesis fungicides currently prohibited by European legislation. In this scenario, screening for less sensitive cultivars is regarded as a sustainable approach for GTDs management. In the study presented herein, the tolerance/susceptibility of 25 cultivars from the Grapevine Germplasm Bank of Aragon (Movera, Zaragoza, Spain) including commercial, local, or minority germplasm, was tested against two pathogens associated with Botryosphaeria dieback (viz. Neofusicoccum parvum and Diplodia seriata), which were inoculated in a detached cutting assay under open-air conditions. Based on lesion length development after eight months, significant differences were detected among the cultivars in the length of internal (vascular) necroses. In general terms, all cultivars were susceptible to fungal infection, but 'Macabeo' and one of the 'Garnacha Tinta' ecotypes under study (from Villanueva de Huerva, Zaragoza) would be the least susceptible white and red cultivars, respectively. On the other hand, 'Monegrina', 'Grumel', and 'Torcijón' would be among the least tolerant cultivars to fungal infection. [ABSTRACT FROM AUTHOR]

Three fungal strains designated as KNUF-23-MG32, KNUF-23-YC8, and KNUF-23-MJ82 were isolated from the abnormal symptomatic apple trees during screening fungal pathogens collected in Jeollanam-do and Gyeongsangbuk-do, Korea. These fungal strains were found to have similar cultural and morphological characteristics close to the genus Botryosphaeria. Morphological characteristics were matched with B. kuwatsukai CBS 135219 but different with B. dothidea KACC 45481 and B. sinensis HMAS 246714T. Pathogenicity tests of strain KNUF-23-MG32 showed that this strain causes rot in Fuji apples. Molecular phylogenetic analysis based on the sequences of the internal transcribed spacer (ITS) regions, translation elongation factor 1-alpha (TEF1α), and partial β-tubulin (TUB2) showed that these strains are B. kuwatsukai. To the best of our knowledge, this is the first report of an apple ring rot fungus Botryosphaeria kuwatsukai in Korea.