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Grapevine (Vitis vinifera) is one of the significant fruit trees cultivated in Iraq. During 2018-2019, severe leaf spot symptoms were observed commonly on grapevine in Al-Hussainiya district, Karbala province, Iraq. In order to identify the etiology of this disease, symptomatic leaf samples were collected randomly. The associated fungus was isolated, purified and identified as Alternaria alternata according to its morphological characteristics and sequence analyses of the internal transcribed spacer (ITS) region of the ribosomal DNA (rDNA). The pathogenicity assay using Koch's postulates approved that the isolated A. alternata was pathogenic on grapevine leaves. The current study represents the first record of A. alternata causing leaf spots on grapevine in Karbala province, Iraq. [ABSTRACT FROM AUTHOR]

Citrus trees are affected by many plant‐pathogenic fungi. The present study aimed to characterize Colletotrichum species on citrus showing anthracnose symptoms, leaf and fruit spot and wither tip in northern Thailand using multilocus data and assay their pathogenicity. The surveys were carried out from December 2021 to January 2022 and 73 isolates were obtained from infected tissues. The fungal strains were identified based on morphological traits and were confirmed via amplification and sequencing of ITS, ACT, CHS‐1, GAPDH and TUB2. In all, 41 isolates were subjected to multilocus phylogeny. Forty of these isolates of Colletotrichum species belonged to the C. gloeosporioides species complex and one isolate belonged to the C. orchidearum species complex. Colletotrichum siamense, comprising 19 isolates, was the most dominant species associated with symptomatic citrus, followed by C. gloeosporioides (17 isolates), C. fructicola (three isolates), C. endophytica (one isolate) and C. plurivorum (one isolate). C. plurivorum is reported for the first time from citrus in the world. These isolates were obtained from mandarin (Citrus reticulata), pomelo (C. maxima), Persian lime (C. latifolia), Thai lime (C. hystrix) and acid lime (C. aurantifolia). The pathogenicity of the isolated fungi was tested through inoculation on branch, fruit and leaf using the detached method on mandarin, pomelo and Persian lime hosts, confirming Koch's postulate. In terms of disease severity, C. gloeosporioides and C. siamense were observed to be the most pathogenic species. This is the first pathogenic and molecular study of Colletotrichum species infecting citrus in northern Thailand. [ABSTRACT FROM AUTHOR]

Pseudostellaria heterophylla, a valuable Chinese herbal medicine, is widely cultivated in China, with a planted area of 5402.7 hm2 in Shibing County, Guizhou Province. The occurrence of leaf spot disease represents a significant challenge in the production area. In this study, 30 samples of P. heterophylla exhibiting symptoms of leaf spot were collected from three primary production areas in Guizhou Province. Following isolation and purification, 51 isolates were classified into two genera based on both cultural and conidial characteristics, along with ITS sequence data. Fourteen representative strains were selected for morphological and multigene molecular identification, which revealed that these representative strains were affiliated with Alternaria arborescens species complex (SC), Alternaria tenuissima, Alternaria gaisen, and Sclerotiophoma versabilis. The isolation rates of Alternaria and Sclerotiophoma were 84.3% and 15.7%, respectively. Pathogenicity tests confirmed the identity of the causal agents and demonstrated varying levels of aggressiveness among the different genera and species of pathogens towards P. heterophylla leaves. This study marks the first identification of A. arborescens SC, A. gaisen, and S. versabilis as pathogens causing leaf spot in P. heterophylla in China. [ABSTRACT FROM AUTHOR]

The European Commission requested the EFSA Panel on Plant Health to conduct a pest categorisation of Coniella castaneicola (Ellis & Everh) Sutton, following commodity risk assessments of Acer campestre, A. palmatum, A. platanoides, A. pseudoplatanus, Quercus petraea and Q. robur plants from the UK, in which C. castaneicola was identified as a pest of possible concern to the EU. When first described, Coniella castaneicola was a clearly defined fungus of the family Schizoparmaceae, but due to lack of a curated type‐derived DNA sequence, current identification based only on DNA sequence is uncertain and taxa previously reported to be this fungus based on molecular identification must be confirmed. The uncertainty on the reported identification of this species translates into uncertainty on all the sections of this categorisation. The fungus has been reported on several plant species associated with leaf spots, leaf blights and fruit rots, and as an endophyte in asymptomatic plants. The species is reported from North and South America, Africa, Asia, non‐EU Europe and Oceania. Coniella castaneicola is not known to occur in the EU. However, there is a key uncertainty on its presence and geographical distribution worldwide and in the EU due to its endophytic nature, the lack of systematic surveys and possible misidentifications. Coniella castaneicola is not included in Commission Implementing Regulation (EU) 2019/2072 and there are no interceptions in the EU. Plants for planting, fresh fruits and soil and other growing media associated with infected plant debris are the main pathways for its entry into the EU. Host availability and climate suitability in parts of the EU are favourable for the establishment and spread of the fungus. Based on the scarce information available, the introduction and spread of C. castaneicola in the EU is not expected to cause substantial impacts, with a key uncertainty. Phytosanitary measures are available to prevent its introduction and spread in the EU. Because of lack of documented impacts, Coniella castaneicola does not satisfy all the criteria that are within the remit of EFSA to assess for this species to be regarded as potential Union quarantine pest. [ABSTRACT FROM AUTHOR]

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The tea plant, Camellia sinensis [L.] O. Kuntze, is a vital global agricultural commodity, yet faces challenges from fungal infections, which affects its production. To reduce the loss in the tea production, the fungal infections must be removed which is managed with fungicides, which are harmful to the environment. Leaf necrosis, which decreases tea quality and quantity, was investigated across Assam, revealing Lasiodiplodia theobromae as the causative agent. Pathogenicity tests, alongside morphological and molecular analyses, confirmed its role in leaf necrosis. Genome and gene analysis of L. theobromae showed multiple genes related to its pathogenicity. The study also assessed the impact of chemical pesticides on this pathogen. Additionally, the findings in this study highlight the significance of re-assessing management approaches in considering the fungal infection in tea. [ABSTRACT FROM AUTHOR]

AbstractFigs (Ficus carica L.) are widely cultivated throughout the world owing to their excellent medical and edible value. In October 2021, we discovered a new leaf target-spot disease associated with the common fig in China. It is necessary to identify the causal agent, as it seriously affects the normal growth of figs and reduces their economic value. The initially infected leaves displayed light yellow lesions between the leaf veins. Under conditions of suitable temperature and humidity, the lesions expanded rapidly with light brown in the middle and dark brown at the margin accompanied by a yellow halo, and typical target holes appeared in the centre of the lesions. Three filamentous fungi were isolated from infected leaves, among which the isolate WHG-3 exerted the strongest virulence in vitro. Its newly grown mycelia were white and then gradually turned to dark grey. The conidia were hyaline, spindle-shaped or oval, with thin cell walls. Phylogenetic analyses based on the ITS, tef-1 and tub2 gene sequences verified that the isolates WHG-3, WHG-4 and WHG-5 were Neofusicoccum parvum. To the best of our knowledge, this is the first report that N. parvum causes leaf target-spot on Ficus carica L. in China. [ABSTRACT FROM AUTHOR]

The objective of the current investigation was to identify the genotypes that are resistant to Stem Borer, Leaf Folder and Leaf Spot through screening under natural conditions. The experimental material composed of 34 genotypes, and screening for resistance to Stem Borer, Leaf Folder, and Leaf Spot was done by planting infector rows alongside the test entries. The results showed that most of the genotypes studied were categorized as free or highly susceptible to the attack of Stem Borer, Leaf Folder and Leaf Spot. The genotypes showed various reactions, including Free (F), Highly Resistant (R), Resistant (R), Moderately Resistant (MR), Moderately Susceptible (MS), Susceptible (S), and Highly Susceptible (HS), based on pest and disease attack. Despite the variable response to the Leaf Folder, the genotypes ADT 45, ADT 46, ADT 54, Salem Senna, Karuppu Kavuni, Mottakar, Anna (R) 4, TRY 1, TRY 3 and Kalsar exhibited a resistant nature. In the case of Stem Borer, the genotypes ADT 43, ADT 45, ADT 46, Kattuyanam, Kallurundai, TRY 3, and Sivappukar exhibited the resistant nature. For Leaf Spot, the genotypes ADT 45, ADT 46, Kattuyanam and Attur Kichidi Samba were found to be resistant, and these genotypes could be used as donors to develop Stem Borer, Leaf Folder, and Leaf Spot resistant lines. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Henan Agricultural Sciences is the property of Editorial Board of Journal of Henan Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract The European Commission requested the EFSA Panel on Plant Health to conduct a pest categorisation of Coniella castaneicola (Ellis & Everh) Sutton, following commodity risk assessments of Acer campestre, A. palmatum, A. platanoides, A. pseudoplatanus, Quercus petraea and Q. robur plants from the UK, in which C. castaneicola was identified as a pest of possible concern to the EU. When first described, Coniella castaneicola was a clearly defined fungus of the family Schizoparmaceae, but due to lack of a curated type‐derived DNA sequence, current identification based only on DNA sequence is uncertain and taxa previously reported to be this fungus based on molecular identification must be confirmed. The uncertainty on the reported identification of this species translates into uncertainty on all the sections of this categorisation. The fungus has been reported on several plant species associated with leaf spots, leaf blights and fruit rots, and as an endophyte in asymptomatic plants. The species is reported from North and South America, Africa, Asia, non‐EU Europe and Oceania. Coniella castaneicola is not known to occur in the EU. However, there is a key uncertainty on its presence and geographical distribution worldwide and in the EU due to its endophytic nature, the lack of systematic surveys and possible misidentifications. Coniella castaneicola is not included in Commission Implementing Regulation (EU) 2019/2072 and there are no interceptions in the EU. Plants for planting, fresh fruits and soil and other growing media associated with infected plant debris are the main pathways for its entry into the EU. Host availability and climate suitability in parts of the EU are favourable for the establishment and spread of the fungus. Based on the scarce information available, the introduction and spread of C. castaneicola in the EU is not expected to cause substantial impacts, with a key uncertainty. Phytosanitary measures are available to prevent its introduction and spread in the EU. Because of lack of documented impacts, Coniella castaneicola does not satisfy all the criteria that are within the remit of EFSA to assess for this species to be regarded as potential Union quarantine pest.

Eggplant is one of the major vegetables consumed worldwide. Several fungal, bacterial, and viral diseases challenge the yield and quality of eggplant. The incidence of plant diseases is strongly influenced by weather factors such as temperature, humidity, rainfall, and wind speed. Mattu Gulla (MG) is a GI-tagged traditional variety of eggplant grown in Mattu village of the Udupi district in Karnataka state, India, with a cultural legacy of more than four centuries. In this study, we investigated the relationships between weather parameters and disease incidence in Mattu Gulla. Leaf spot (LS) and fruit rot (FR) are the major diseases affecting this plant variety. The influence of plant age and weather parameters on the modulation of the disease incidence (%) [DI (%)] of leaf spot and fruit rot was recorded and analyzed via correlation and regression. Prediction equations for disease incidence was derived via regression. A significant negative correlation was observed between the leaf spot DI (%) and minimum temperature (Min. temp), and a positive correlation was observed between the DI (%) and fruit rot. In the case of FR, the DI (%) is also significantly positively correlated with wind speed (WS), temperature, maximum relative humidity (RH I), rainfall (RF), and wind speed (WS). An RH I of 86–87 % was favorable for the incidence of fruit rot in the field. Regression analysis revealed a significant association between Min. temp and leaf spot DI (%), and in the case of fruit rot DI (%), the association was with Min. temp and WS. An android application, “Leaf Guard,” has been developed for AI-based disease detection in eggplant. During testing, the accuracy of the trained model reached 98.2 %.

During the summers of 2022 and 2023, leaf spots suspected to be anthracnose were observed on the leaves of Rubus crataegifolius (Korean raspberry) grown in an orchard in Gimhae, South Korea. Approximately 20% of the Korean raspberry plants on the farm where the disease was discovered were confirmed to be infected. The morphological features of the fungal isolates were coincident to the descriptions of Colletotrichum gloeosporioides species complex. Phylogenetic analyses of concatenated sequences of the ITS, ACT, CAL, CHS-1, and GAPDH genes identified the causative agent as Colletotrichum aenigma. Pathogenicity tests confirmed that this fungal species is pathogenic to R. crataegifolius. To the best of our knowledge, this is the first report of C. aenigma on Korean raspberry in Korea and the world. [ABSTRACT FROM AUTHOR]

In 2020, leaf spots were observed on Datura innoxia plants in Curitiba, Brazil. Alternaria alternata was identified after isolation from symptomatic leaves through morphological characterization, along with sequencing of the partial tef, gapdh, and rpb2 genes and phylogenetic analysis. Pathogenicity was proven using Koch's Postulates. This is the first report of this species causing disease in Datura spp. worldwide. [ABSTRACT FROM AUTHOR]

Agave genera include slow-growing plants with cultural and economic roots dating back to pre-Columbian times in Mexico. Several species have a widespread presence in the country and are cultivated and/or used directly from the field to obtain various derived products. Agave salmiana is widely used in the region of the High Valleys of Apan, Hidalgo, Mexico. However, fungal diseases are causing considerable losses to Agave crops. For this reason, fungi strains from maguey plants from Apan, Hidalgo, with "Negrilla" disease symptoms were isolated and identified morphologically and molecularly. The results provide information on a new disease disseminated in A. salmiana plants, which causes symptoms such as black spots on the leaves due to pathogenic fungi of the genera Bipolaris. The morphological and molecular characterization located the phytopathogenic fungus as new isolates of Bipolaris zeae. Finally, the re-isolation of the causal agent of the disease was achieved in all pathogenicity tests, verifying that the symptoms observed in the maguey plants were caused by B. zeae, thus corroborating Koch's postulates, and constituting the first report of this fungus as a pathogen of A. salmiana in Mexico. [ABSTRACT FROM AUTHOR]

Septoria leaf spot on hemp has re-emerged with increasing hemp cultivation worldwide. In Japan, Septoria cannabis, initially recorded as the causal pathogen in Japan, was studied with morphology based on the current criteria and detailed molecular phylogenetic analyses using seven gene loci. The robust phylogenetic data and morphology of examined specimens unveiled the existence of a new species of the genus Septoria causing leaf spot disease on Cannabis sativa. [ABSTRACT FROM AUTHOR]

Early blight (EB), caused by the dominant species Alternaria alternata, is a major global disease of tomato (Solanum lycopersicum L.; Solanaceae) reducing the vegetative organs and causing losses. Sustainable food production mainly depends on the rational use of chemical fertilizers and fungicides in integrated plant disease management. Hence, the fungicidal activity of ortivatop® (azoxystrobin + difenoconazole), Signum WG 33.4% (pyraclostrobin + boscalid) and daconyl SC 72% (chlorothalonyl) was evaluated against tomato EB disease under field conditions. Two experiments were conducted during the cropping seasons from 2019 to 2020 in three regions. The experimental design was a randomized block with 4 replications using Ortivatop® (ORT) at three doses of -900, -1100 and -1300 ml. ha−1 (recommended doses of the company), daconyl (DAC) 2 l. ha−1 and Signum (SIG) 0.5 l. ha−1. The findings showed that ORT-1300 (20.6%) and DAC (22.7%) resulted in the lowest EB disease severity, followed by SIG (25.7%), ORT-1100 (26.9%) and ORT-900 (31.7), in contrast to 59.1% of the control. Compared with treatment without fungicide, all fungicides reduced the AUDPC (area under disease progress curve) and provided an increase in productivity. ORT-1300 ml ha−1 showed the greatest reduction in AUDPC by up to 70% and increased tomato yield by threefold more than the untreated control. Therefore, the current study suggests that foliar spraying with ORT-1300 ml. ha−1 at all three growth stages, is an ideal solution for EB disease management. [ABSTRACT FROM AUTHOR]

One of the most common vegetable crops in the world is the tomato (Solanum lycopersicum L). Despite an increase in the area under tomato cultivation, production has not kept up. One of the most significant obstacles to the yield of tomato crops is the Alternaria pathogen. In this study, 11 Alternaria species were isolated from tomato leaves and identified using a morphological and molecular tool based on ITS regions of the rDNA sequences. Fe (iron) nanoparticles (NPs) were created in the current investigation utilizing cow urine. The surface morphology and synthesis of metal oxide functional groups were studied using Scanner electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Preliminary x-ray diffraction (XRD) reveals that Fe nanoparticles have a hexagonal structure with a space group (P63mc) (FTIR). Cow urine, Fe nanoparticles, and their combination (CU+ FeNPs) were tested for their effectiveness in vitro and in vivo against the leaf spot pathogen The lethal action of FeNPs on leaf spot may be mediated by ROS, which plays a function in NPs by inhibiting A. alternata growth. In the future, the use of CU + FeNPs combination in crop production mainly to increased yield quality, and manage diseases should be promoted. As far as we know, this is the first attempt made to manage this important pathogen (leaf spot pathogen) in tomato plants using a combination of CU + FeNPs together under field conditions. [ABSTRACT FROM AUTHOR]

Worldwide, the genus Colletotrichum has been poorly documented in forest trees compared to crops. In Chile, most of the records from native plants date from the beginning of the last century, and only a few species are properly identified according to modern taxonomy. To contribute to the knowledge of Colletotrichum species diversity in Chilean native forests, we examined 50 strains collected from 17 woody plant hosts between 36 and 40° S latitude in south-central Chile. Based on morphological characters, multi-locus phylogenetic analyses (ITS, GAPDH, CHS-1, HIS3, ACT, TUB2), and coalescent-based species delimitation methods, we identified ten species belonging to the Colletotrichum acutatum and Colletotrichum boninense species complexes. These were identified as Colletotrichum arboricola, C. brassicicola, C. godetiae, C. pyricola, C. rhombiforme, and C. roseum, along with the new species described here as C. americanum, C. laurosilvaticum, C. palki, and C. perseicola. We also propose to synonymize C. lauri with C. godetiae and C. australisinense with C. wanningense. [ABSTRACT FROM AUTHOR]

In the growth season of 2018-2019, plum trees in many orchards in the Al-Hussainiya district of Karbala Province, Iraq, regularly exhibited severe symptoms of leaf spot. The prevalence of the disease was estimated to be 15%. The causal factor responsible for this disease has been determined as Alternaria alternata based on its morphological and molecular characteristics. The pathogenicity of the isolated A. alternata was assessed using Koch's postulates, which confirmed its pathogenic nature. Therefore, it was once again isolated from the affected symptomatic leaves. The results outline the scientific methodology used to identify the causal agent responsible for the Alternaria leaf spot disease on plum trees. This is the first report of A. alternata causing leaf spot on plum trees in Karbala province, Iraq. [ABSTRACT FROM AUTHOR]

Fritillaria taipaiensis P. Y. Li is one of the biological sources for Fritillariae Cirrhosae Bulbus. Its bulbs are widely used for treating respiratory diseases such as pneumonia, bronchitis and influenza. Cultivated F. taipaiensis suffers from many diseases during its growing season. Leaf spot is a destructive disease that is increasingly affecting F. taipaiensis and can cause an incidence of up to 30% in severe cases. Leaf spot inhibits the growth of F. taipaiensis by causing disease spots on the surface of leaves. In severe cases, these spots can result in leaf desiccation and blackspot formation at the lesion site, leading to a decrease in photosynthesis. Leaf spot has shown little benefit, and it can even result in a reduced yield of bulbs and the death of plants. According to previous studies, Alternaria alternata has been identified as the pathogen of leaf spot in many medicinal plants, but the main pathogens of the leaf spot of F. taipeiensis remains uncertain. In this paper, five isolates from diseased leaves of F. taipaiensis were isolated and purified and the pathogenicity test showed that isolates B-5 and B-7 induced leaf spot symptoms on healthy F. taipaiensis leaves. Integrating multiple phylogenetic analyses of rDNA using Internal transcribed spacer region (ITS), Beta-tubulin (TUB2), RNA polymerase II second largest subunit (RPB2) and Translation elongation factor 1-alpha (TEF1-a) primers, strain B-5 and strain B-7 were eventually identified as Didymella segeticola and A. alternata. This is also the first report on the pathogens that cause leaf spot in F. taipaiensis in China. [ABSTRACT FROM AUTHOR]

Tetrapanax papyrifer, the rice‐paper plant, is an evergreen shrub and is traditionally used as a herbal medicine in China. In October 2021, a serious leaf spot disease was extensively observed on T. papyrifer in Guizhou, China. Given the limited information available about the aetiology of this disease, isolations were performed, the morphological characteristics and multi‐locus phylogenetic analysis of the fungus associated with the disease were described, and the pathogenicity tests and Koch's postulates were completed. To our knowledge, this is the first report of leaf spot on T. papyrifer caused by Alternaria tenuissima in China. Among 11 fungicides tested, 10% difenoconazole WDG had the best inhibition effect in vitro with EC50 values at 0.1 μg mL−1. This study provides new information for the identification and chemical control of Alternaria leaf spot of T. papyrifer. [ABSTRACT FROM AUTHOR]

In September 2022, a leaf spot disease, which later coalesce and result into leaf defoliation of rubber was observed in Tungawan, Zamboanga Sibugay, Philippines. Morpho‐cultural and molecular characterization identified the pathogen as Neopestalotiopsis clavispora. Koch's postulates were fulfilled confirming its pathogenicity to rubber seedlings. To the best of our knowledge, this is the first report of N. clavispora infecting rubber in the Philippines. [ABSTRACT FROM AUTHOR]

Colletotrichum fructicola, one of the dominant pathogens isolated from the main tea region in China, causes leaf spot in mature leaves of tea plants, affecting their growth and yield. Here, we present the draft whole‐genome sequence of the C. fructicola strain SX‐6 previously used for morphological and transcriptomic analyses. The assembly consists of 510 contigs with an estimated genome size of 56.8 Mb. A total of 15,243 predicted protein‐coding genes in the SX‐6 genome were annotated using NR, Swiss‐Prot, KEGG, KOG, TCDB, GO, PHI, DFVF, P450, SignalP and CAZy databases. We identified 833 carbohydrate‐active enzymes, 1803 secreted proteins, 79 secondary metabolite gene clusters and 576 fungal virulence factors that may be involved in the pathogenicity of this fungus. Comparative genome analyses with 25 Colletotrichum species revealed their evolutionary relationships via a constructed phylogenetic tree and identified four gene families whose genes were significantly more abundant in strain SX‐6. The resulting assembly will provide a valuable resource for further research on the gene functions of C. fructicola. [ABSTRACT FROM AUTHOR]

Apoharknessia eucalyptorum is associated with leaf spots on Eucalyptus dunnii in Southern Brazil; however, no data about its symptoms and severity are currently available. In this study, inoculation, symptomatology, and severity on leaves and stems of E. dunnii and leaves of Corymbia citriodora are analyzed and discussed. Detached and intact seedling leaves and seedling stems, with and without wounds, were inoculated with A. eucalyptorum. The severity of leaves was assessed based on the lesion area, whereas the severity on stems was considered by the size of the lesions. After inoculation, the following symptoms were observed on leaves with and without lesions: brown, circular or irregular lesions, occurring along the leaf margins, sparsely distributed, or coalescing throughout the leaf blade. The severity on detached leaves ranged from 13 to 63 % on E. dunnii and from 30 to 38 % on C. citriodora, whereas on intact seedling leaves the severity was observed only on wounded tissues, with 11.90 % on E. dunnii and 19.63 % on C. citriodora. Only inoculated stems of E. dunnii with wounds showed signs of the pathogen. This study confirms the pathogenicity of A. eucalyptorum on both E. dunnii and C. citriodora, a new host for the disease, and concludes that although the pathogen can be considered a primary pathogen based on detached leaf inoculations, the infection on non-wounded tissues is limited. Thus, the distribution of A. eucalyptorum and the possible impacts of the pathogen on Eucalyptus spp. plantations should be monitored. [ABSTRACT FROM AUTHOR]

AbstractDuring a disease survey in October 2019, leaf spot symptoms with a yellow halo were observed on Korean angelica (Anglica gigas) plants grown in fields in Pyeongchang, Gangwon Province, Korea. Incidence of diseased leaves of the plants in the investigated fields ranged from 10% to 60%. Morphological and cultural characteristics of two single-spore isolates from the leaf lesions indicated that they belonged to the genus Didymella. Molecular phylogenetic analyses using combined sequences of LSU, ITS, TUB2, and RPB2 regions showed distinct clustering of the isolates from other Didymella species. In addition, the morphological and cultural characteristics of the isolates were somewhat different from those of closely related Didymella spp. Therefore, the novelty of the isolates was proved based on the investigations. Pathogenicity of the novel Didymella species isolates was confirmed on leaves of Korean angelica plants via artificial inoculation. This study reveals that Didymella gigantis sp. nov. causes leaf spot in Korean angelica.

Cercospora apii is an important seedborne pathogenic fungus causing severe Cercospora leaf spot of celery worldwide. Here, we first present a complete genome assembly of C. apii QCYBC from celery, based on Illumina paired-end and PacBio long-read sequencing data. The high-quality genome assembly contains 34 scaffolds with a 34.81 Mb genome size, 330 interspersed repeat genes, 114 noncoding RNAs, and 12,631 protein-coding genes. The benchmarking universal single-copy ortholog (BUSCO) analysis indicated that 98.2% of the BUSCOs were complete, whereas 0.3, 0.7, and 1.1% were duplicated, fragmented, and missing, respectively. Based on annotation, 508 carbohydrate-active enzymes, 243 cytochromes P450 enzymes, 1,639 translocators, 1,358 transmembrane proteins, and 1,146 virulence genes were identified. This genome sequence provides a valuable reference for future studies to improve understanding of the C. apii–celery pathosystem. [Graphic: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

During a disease survey in October 2019, leaf spot symptoms with a yellow halo were observed on Korean angelica (Anglica gigas) plants grown in fields in Pyeongchang, Gangwon Province, Korea. Incidence of diseased leaves of the plants in the investigated fields ranged from 10% to 60%. Morphological and cultural characteristics of two single-spore isolates from the leaf lesions indicated that they belonged to the genus Didymella. Molecular phylogenetic analyses using combined sequences of LSU, ITS, TUB2, and RPB2 regions showed distinct clustering of the isolates from other Didymella species. In addition, the morphological and cultural characteristics of the isolates were somewhat different from those of closely related Didymella spp. Therefore, the novelty of the isolates was proved based on the investigations. Pathogenicity of the novel Didymella species isolates was confirmed on leaves of Korean angelica plants via artificial inoculation. This study reveals that Didymella gigantis sp. nov. causes leaf spot in Korean angelica. [ABSTRACT FROM AUTHOR]

From September 2021 to September 2022, leaf spots appeared in hulless barley seedlings in the experimental field of Qinghai University (36°62′ N, 101°77′ E) with an incidence of 35%–60%. In this study, four diseased samples were collected from different experimental sites at Qinghai University for analysis. Moreover, four strains with the same colony and microscopic morphology were isolated. A representative QK‐1 strain was used for DNA extraction and sequencing via PCR amplification using a multi‐gene phylogenetic analysis (ITS, tub2 and EF‐1α). BLAST search revealed that ITS, tub2 and EF‐1α sequence shared 99.59% (accession MH860852), 98.97% (MK926899) and 95.37% (MN078437) nucleotide sequence similarity with isolate CBS276.74 of C. microsporus. The fungus that caused leaf spot of the hulless barley was then identified as Canariomyces microspores. Similar symptoms were observed on hulless barley seedlings after control inoculation with the QK‐1 strain, consistent with the Koch's hypothesis. This is the first study reporting on C. microsporus in Hulless barley in China, suggesting that barley is a new host of C. microsporus. [ABSTRACT FROM AUTHOR]

Following an EFSA commodity risk assessment of bonsai plants (Pinus parviflora grafted on Pinus thunbergii) imported from China, the EFSA Plant Health Panel performed a pest categorisation of Pestalotiopsis microspora, a clearly defined plant pathogenic fungus of the family Pestalotiopsidaceae. The pathogen was reported on a wide range of monocotyledonous, dicotyledonous and gymnosperms, either cultivated or wild plant species, causing various symptoms such as leaf spot, leaf blight, scabby canker, fruit spot, pre‐ and post‐harvest fruit rot and root rot. In addition, the fungus was reported as an endophyte on a wide range of asymptomatic plant species. This pest categorisation focuses on the hosts that are relevant for the EU and for which there is robust evidence that the pathogen was formally identified by a combination of morphology, pathogenicity and multilocus sequencing analyses. Pestalotiopsis microspora was reported in Africa, North, Central and South America, Asia and Oceania. In the EU, it was reported in the Netherlands. There is a key uncertainty on the geographical distribution of P. microspora worldwide and in the EU, because of the endophytic nature of the fungus, the lack of surveys, and because in the past, when molecular tools were not fully developed, the pathogen might have been misidentified as other Pestalotiopsis species or other members of the Pestalodiopsidaceae family based on morphology and pathogenicity tests. Pestalotiopsis microspora is not included in Commission Implementing Regulation (EU) 2019/2072. Plants for planting, fresh fruits, bark and wood of host plants as well as soil and other growing media associated with plant debris are the main pathways for the entry of the pathogen into the EU. Host availability and climate suitability in parts of the EU are favourable for the establishment and spread of the pathogen. The introduction and spread of the pathogen into the EU are expected to have an economic and environmental impact where susceptible hosts are grown. Phytosanitary measures are available to prevent the introduction and spread of the pathogen into the EU. Unless the restricted distribution in the EU is disproven, Pestalotiopsis microspora satisfies all the criteria that are within the remit of EFSA to assess for this species to be regarded as potential Union quarantine pest. [ABSTRACT FROM AUTHOR]

Zanthoxylum bungeanum (family Rutaceae) is an economically important deciduous shrub that is widely distributed across Asia. The leaves of this plant are rich in chemical compounds and have a variety of biological activities. However, a spot disease was discovered on Z. bungeanum leaves in Zunyi, China, in 2020. In the present study, a fungal isolate (YY-815) was obtained from Z. bungeanum leaves with leaf spot symptoms and identified as Didymella segeticola based on its morphological characteristics and phylogenetic analysis. This isolate could cause leaf spot disease and be re-isolated, fulfilling Koch's postulates. The fungicides boscalid, penthiopyrad and pydiflumetofen significantly inhibited hyphal growth of D. segeticola under in vitro conditions. This is the first study to report a leaf spot disease on Z. bungeanum caused by D. segeticola. [ABSTRACT FROM AUTHOR]

Fraxinus americana L. (white ash), a native North American tree commonly cultivated for its ornamental qualities, displayed symptoms of leaf spot disease in a sentinel garden located in Nanjing, Jiangsu, China, in 2022. This disease led to premature leaf shedding, adversely affecting the plant's growth and substantially diminishing its ornamental value. Potential fungal pathogens were isolated from the diseased leaves and the subsequent application of Koch's postulates confirmed the pathogenicity of the fungal isolates (BL-1, BL-2). Through a combination of multi-locus phylogenetic analysis, including ITS, ACT, ApMat, CAL, CHS-1, GAPDH, and TUB2, alongside morphological assessments, the fungus was conclusively identified as Colletotrichum jiangxiense. This represents the first record of C. jiangxiense affecting white ash, highlighting the important role of sentinel gardens in uncovering novel pathogen–plant host interactions. [ABSTRACT FROM AUTHOR]

A leaf spot disease was observed on red veined sorrel (Rumex sanguineus) growing in a commercial greenhouse in northern NSW, Australia, in July 2021. Cercospora rumicis was found in association with the leaf spot and was identified morphologically and by sequencing two gene regions, histone-3 (HIS) and calmodulin (CAL). Koch's postulates were fulfilled through pathogenicity tests, including the inoculation of potted plants and a detached leaf assay. This is the first report of Cercospora rumicis in Australia. [ABSTRACT FROM AUTHOR]

Abstract The aim of the current study was to investigate the pathogenicity of Bipolaris species associated with southern corn leaf blight (SCLB) in Brazil. Fungi were isolated from leaves presenting SCLB symptoms. Morphological features were described when the cultures were grown in Potato dextrose agar (PDA) medium. The ITS and GAPDH regions were used for phylogenetic analyses. The pathogenicity of B. maydis isolates was assessed in four popcorn lines under controlled conditions. Two Bipolaris species among the collected isolates were capable of infecting corn, namely, B. maydis and B. gossypina. Previous studies reporting the infection of corn by B. gossypina were not found; therefore, the present study appears to be the first to report it. Pathological differences between isolates were observed, and there was a significant isolate x line interaction. Line L692 was susceptible in all tests, while Line L623 was resistant to three B. maydis isolates. The isolate CF/UENF 482 of B. gossypina did not generate symptoms in the tested popcorn lines. The B. maydis isolates CF/UENF 477 and CF/UENF 501 were the most virulent. [ABSTRACT FROM AUTHOR]

Soybean (Glycine max) as an oilseed crop plays a vital role in agro-based industries. However, its sustainable production is challenged by biotic and abiotic factors. Fungal pathogens infecting soybean are a major concern. But, their extent in Pakistan is less explored. During crop season 2019-20, soybean plants showing leaf spots were observed in a research trial. Infected samples were assayed for isolation of pathogen on potato dextrose agar. Initial mycelial growth was purified on fresh nutrient media. Based on growth pattern and microscopic observations, the fungus was identified as Alternaria alternata. Koch postulates also confirmed by inoculating spore suspension of A. alternata in soybean plants under controlled environmental conditions. Moreover, phenotypic features of fungus were validated through amplification of internal transcribed spacer (ITS) regions using ITS-1and ITS-4 primers. Amplicon size of 570-bp was sequenced and NCBI BLASTn results confirmed fungus as A. alternata. Representative sequences of isolates (NBG1-4) were submitted to public database NCBI with accession numbers MZ769364-67. Phylogenetic study also inferred their relationship with previously reported isolates of A. alternata. Morphological feature of fungus, its pathogenicity and molecular characterization revealed the association of A. alternata with leaf spot in soybean. These results confirmed the incidence of leaf spot of soybean caused by A. alternata for the first time from Pakistan. [ABSTRACT FROM AUTHOR]

Maize (Zea mays L.) is one of the most important crops, influencing food production and even the whole industry. In recent years, global crop production has been facing great challenges from diseases. However, most of the traditional methods make it difficult to efficiently identify disease-related phenotypes in germplasm resources, especially in actual field environments. To overcome this limitation, our study aims to evaluate the potential of the multisensor synchronized RGB-D camera with depth information for maize leaf disease classification. We distinguished maize leaves from the background based on the RGB-D depth information to eliminate interference from complex field environments. Four deep learning models (i.e., Resnet50, MobilenetV2, Vgg16, and Efficientnet-B3) were used to classify three main types of maize diseases, i.e., the curvularia leaf spot [Curvularia lunata (Wakker) Boedijn], the small spot [Bipolaris maydis (Nishik.) Shoemaker], and the mixed spot diseases. We finally compared the pre-segmentation and postsegmentation results to test the robustness of the above models. Our main findings are: 1) The maize disease classification models based on the presegmentation image data performed slightly better than the ones based on the post-segmentation image data. 2) The pre-segmentation models overestimated the accuracy of disease classification due to the complexity of the background, but post-segmentation models focusing on leaf disease features provided more practical results with shorter prediction times. 3) Among the post-segmentation models, the Resnet50 and MobilenetV2 models showed similar accuracy and were better than the Vgg16 and Efficientnet-B3 models, and the MobilenetV2 model performed better than the other three models in terms of the size and the single image prediction time. Overall, this study provides a novel method for maize leaf disease classification using the post-segmentation image data from a multi-sensor synchronized RGB-D camera and offers the possibility of developing relevant portable devices. [ABSTRACT FROM AUTHOR]

This article explores the morph-cultural variability of Alternaria alternata, a fungus that causes leaf spot disease in ber plants in Eastern Uttar Pradesh. The study analyzed six different isolates of A. alternata and found significant variation in terms of mycelial growth, colony appearance, sporulation, and conidial characteristics. The findings provide valuable information for understanding the variability of A. alternata populations and can help in developing strategies to manage the disease. The study also highlights the presence of new races of the pathogen in the region, indicating the need for further research. [Extracted from the article]

During disease surveys of Angelica acutiloba plants in Korea, leaf spot symptoms were observed in a field in Andong in July 2019, and stem rot symptoms in vinyl greenhouses in Yangpyeong in April 2020. Incidence of leaf spot and stem rot of the plants ranged from 10 to 20% and 5 to 30%, respectively. Morphological and cultural characteristics of fungal isolates from the leaf spot and stem rot symptoms fitted into those of the genus Phoma. Molecular phylogenetic analyses of two single-spore isolates from the symptoms using concatenated sequences of LSU, ITS, TUB2, and RPB2 genes authenticated an independent cluster from other Didymella (anamorph: Phoma) species. Moreover, the isolates showed different morphological and cultural characteristics in comparison to closely related Didymella species. These discoveries confirmed the novelty of the isolates. Pathogenicity of the novel Didymella species isolates was substantiated on leaves and stems of A. acutiloba through artificial inoculation. Thus, this study reveals that Didymella acutilobae sp. nov. causes leaf spot and stem rot in Angelica acutiloba. [ABSTRACT FROM AUTHOR]

Background: Leaf spot disease (LSD) of mulberry caused by Phloeospora maculans is a major threat to the silk industry of Jammu and Kashmir, India, therefore, it was necessary to study the population structure of the pathogen for successful management of the disease. Methods and results: To understand the diversity in the Phloeospora maculans, a combination of conventional (morphological, cultural and pathological) and molecular (ISSR markers) approaches were employed to discern the variability in 27 isolates collected from Srinagar, Bandipora, and Baramulla districts of Jammu and Kashmir, India. The studies revealed a high level of variability in the pathogen. Based on the morpho-cultural and pathological studies, the pathogen isolates were grouped into different categories based on colony growth, texture, margin and colour besides changes in colour of medium, incubation period, leaf area infected, etc.A high level of polymorphism was observed in different isolates of P. maculans using ISSR markers, which indicated that these markers are suitable for studying the genetic diversity in this pathogen. All the isolates (27) of P. maculans were clustered into two groups or populations as indicated by mean delta K value. Analysis of molecular variance revealed the low genetic variation among the populations (1.08%) and a high level of genetic variation within the populations (98.91%). Fst value was found to be 0.01 indicating smaller amount of genetic differentiation between the populations against calculated P-value of 0.29. Conclusion: A high level of diversity based on morphological, cultural, pathological and molecular levels was observed in Phloeospora maculans collected from various districts of Kashmir valley, which indicates that the study of population structure is necessary for successful management of the disease. [ABSTRACT FROM AUTHOR]

A new type of leaf spot disease of sugarcane was found for first time from Coimbatore, Tamil Nadu, India. While observing the elite sugarcane clones for the manifestation of several foliar diseases such as rust, leaf spot, and Pokkah boeng in September 2021, a leaf spot of sugarcane caused by Exserohilum rostratum was recorded. The pathogen associated with the symptom was identified as E. rostratum based on conidial and morphological characteristics and rDNA-ITS sequence comparison. This is the first occurrence of Exserohilum leaf spot on sugarcane in India, and no previous reports have linked Exserohilum to sugarcane foliar infections. [ABSTRACT FROM AUTHOR]

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The bacterial leaf spot (BLS) is a devastating tomato disease affected by the following Xanthomonas species: X. campestris pv. Vesicatoria, X. euvesicatoria, X. vesicatoria, X. perforans, and X. gardner. Dark lesions and yellow halos on the fruits and foliage are symptoms. The BLS pathogens are widespread in subtropical and tropical areas. Pathogens can be detected using a variety of techniques, most notably a mix of classical and molecular methodologies. Conventional techniques rely on microscopic and culture observation, but Polymerase chain reaction (PCR) and multilocus sequence analysis are obtainable. Control of BLS is problematic because of the infections extensive genetic variety, an absence of durable host resistance, and the ineffectiveness of chemical management. Various bicontrol agents, such as bacteriophage, bacteria and fungi have been documented. Including sustained host resistance is an essential component of continuing integrated BLS management. This review involved state of BLS in tomato comprising its prevalence, pathogen profiles, investigative tools, disease control and resistance development in plant. [ABSTRACT FROM AUTHOR]

Abstract Following an EFSA commodity risk assessment of bonsai plants (Pinus parviflora grafted on Pinus thunbergii) imported from China, the EFSA Plant Health Panel performed a pest categorisation of Pestalotiopsis microspora, a clearly defined plant pathogenic fungus of the family Pestalotiopsidaceae. The pathogen was reported on a wide range of monocotyledonous, dicotyledonous and gymnosperms, either cultivated or wild plant species, causing various symptoms such as leaf spot, leaf blight, scabby canker, fruit spot, pre‐ and post‐harvest fruit rot and root rot. In addition, the fungus was reported as an endophyte on a wide range of asymptomatic plant species. This pest categorisation focuses on the hosts that are relevant for the EU and for which there is robust evidence that the pathogen was formally identified by a combination of morphology, pathogenicity and multilocus sequencing analyses. Pestalotiopsis microspora was reported in Africa, North, Central and South America, Asia and Oceania. In the EU, it was reported in the Netherlands. There is a key uncertainty on the geographical distribution of P. microspora worldwide and in the EU, because of the endophytic nature of the fungus, the lack of surveys, and because in the past, when molecular tools were not fully developed, the pathogen might have been misidentified as other Pestalotiopsis species or other members of the Pestalodiopsidaceae family based on morphology and pathogenicity tests. Pestalotiopsis microspora is not included in Commission Implementing Regulation (EU) 2019/2072. Plants for planting, fresh fruits, bark and wood of host plants as well as soil and other growing media associated with plant debris are the main pathways for the entry of the pathogen into the EU. Host availability and climate suitability in parts of the EU are favourable for the establishment and spread of the pathogen. The introduction and spread of the pathogen into the EU are expected to have an economic and environmental impact where susceptible hosts are grown. Phytosanitary measures are available to prevent the introduction and spread of the pathogen into the EU. Unless the restricted distribution in the EU is disproven, Pestalotiopsis microspora satisfies all the criteria that are within the remit of EFSA to assess for this species to be regarded as potential Union quarantine pest.