Jul 2026· Asian-Australasian journal of food safety and security· Vol 10, pp. 56-63· 0 citations· 24 references
TL;DR
This study constitutes the first molecularly confirmed record of A. alternata infecting cabbage in Bangladesh and will support future disease monitoring efforts and contribute to the formulation of appropriate management practices for sustainable cabbage production.
Abstract
Cabbage (Brassica oleracea var. capitata) is one of the major winter vegetables grown in Bangladesh, recognized for its dietary value and economic importance. During November 2023, cabbage leaves exhibiting typical leaf spot symptoms were collected from the Bangladesh Agricultural Research Institute (BARI), Gazipur, to identify the associated pathogen. The infected leaves showed dark brown to black necrotic lesions with concentric rings characteristic of Alternaria leaf spot. The pathogen was isolated on Potato Dextrose Agar (PDA) and purified using a single-conidium isolation technique. Morphological characterization revealed colony and conidial features consistent with Alternaria alternata. To confirm the pathogen identity, molecular characterization was performed using the internal transcribed spacer (ITS) region of rDNA. Amplification with ITS1/ITS4 primers generated a 510 bp fragment, and the resulting sequence was deposited in GenBank under accession number OP585635. Comparison of the obtained sequence against the GenBank database revealed a high degree of homology (99%) with previously deposited A. alternata sequences. The phylogenetic tree also placed the isolate in the same evolutionary group as A. alternata, with 88% bootstrap support. Species-specific PCR using A. alternata-specific primers produced the expected 184 bp amplicon, providing additional confirmation of species identity. Pathogenicity was evaluated using a detached-leaf assay. Leaves inoculated with the fungal isolate exhibited characteristic disease symptoms comparable to those recorded in naturally infected plants, while no symptoms were detected on the control leaves. Following symptom development, the fungus was recovered from infected tissues and its identity was verified using an A. alternata-specific PCR assay, satisfying the requirements of Koch’s postulates. The combined evidence obtained from cultural and microscopic observations, ITS-rDNA sequencing, phylogenetic inference, species-specific molecular detection, and pathogenicity assessment demonstrated that A. alternata was responsible for the leaf spot symptoms observed on cabbage. To our knowledge, this study constitutes the first molecularly confirmed record of A. alternata infecting cabbage in Bangladesh. The information generated will support future disease monitoring efforts and contribute to the formulation of appropriate management practices for sustainable cabbage production.
Asian Australas. J. Food Saf. Secur. 2026, 10(2), 56-63
Alternaria leaf
blight (ALB), caused by the
Alternaria
species complex, is an economic threat to mustard cultivation all over the world. In this study, 700 infected leaf samples were collected from 28 blocks across six districts of the Bundelkhand region, Uttar Pradesh, India. To assess the prevalence and distribution of
Alternaria
species, 28 representative isolates were selected for further study. Morphological traits separated the majority of the Alternaria isolates into three morphotypes corresponding to
A. brassicae
,
A
.
brassicicola
, and
A
.
alternata
, which cause leaf blight. The pathogenicity test revealed that 18 isolates were highly virulent, 6 isolates were moderately virulent, and 4 were less virulent. Molecular analyses of the 18 highly virulent isolates, based on the internal transcribed spacer (ITS) region and the Alternaria-specific
Alt a1 marker
, confirmed the presence of
A. brassicae
(6 isolates),
A. brassicicola
(3 isolates), and
A. alternata
(9 isolates) in the region. Haplotype network analysis of concatenated ITS and Alt a1 sequences revealed two haplotypes among the
A. alternata
isolates and one haplotype each among the A
. brassicae
and
A. brassicicola
isolates. Additionally, all virulent A
. alternata
isolates carried the polyketide synthase genes (
pksH
and
pksJ
), indicating their genetic potential for Alternaria toxin biosynthesis. The predominance of
A
.
alternata
in mustard crops and the presence of toxin-biosynthesis-associated genes may pose a threat to edible oil production and safety, thereby raising serious concerns and warranting further investigation of toxin production. These findings highlighted the need for targeted resistance strategies against the prevalent
Alternaria
species in the region.
Unknown authors· Frontiers in Plant Science· 0 citations
Apple (Malus domestica Borkh.) represents a major fruit crop of global economic importance. Despite its widespread cultivation, fungal diseases infecting branches and vegetative tissues continue to be a major concern, adversely affecting orchard productivity and compromising fruit quality. The present study investigated the fungal pathogen associated with branch canker symptoms observed in apple orchards located in the Al-Jabal Al-Akhdar region, Libya. Symptomatic branch samples exhibiting bark cracking, canker formation, and progressive dieback were collected and subjected to fungal isolation under laboratory conditions. Isolates were purified on potato dextrose agar (PDA) medium and identified according to morphological and microscopic characteristics using standard taxonomic keys. Pathogenicity assays were conducted on healthy apple seedlings to verify the causal relationship between the isolated fungus and disease development. Morphological observations demonstrated that the recovered isolate belonged to Alternaria alternata (Fr.) Keissl., characterized by dark olivaceous to brown colonies and multicellular conidia arranged singly or in short chains. Conidial dimensions ranged from 14.05–14.38 µm in length and 8.07–9.81 µm in width, with 2–8 transverse septa. Artificial inoculation induced typical symptoms, including bark necrosis, branch canker formation, chlorotic lesions, and progressive tissue collapse. Re-isolation from infected tissues successfully fulfilled Koch’s postulates. The findings confirm the pathogenic role of A. alternata in apple branch canker development under local environmental conditions. This study represents one of the first detailed reports concerning the occurrence and pathogenicity of A. alternata associated with apple branch canker in eastern Libya and provides baseline information for future epidemiological and disease management studies
Unknown authors· AlQalam journal of medical a...· 0 citations
Geranium (Pelargonium spp.) is an important ornamental plant susceptible to diseases caused by phytopathogenic fungi, among which Alternaria sp. stands out as the causal agent of brown necrotic leaf spots with concentric zones. Symptomatic samples were collected in March 2025 in the vicinity of Kruševac, and five isolates (MA1–MA5) were selected for further investigation.Pathogenicity was confirmed using the stem wounding method, and inoculated plants developed typical symptoms, including drying and plant death. Morphological and cultural characteristics were examined on PDA, CMA, and WA media; the average conidial size was 29.45 × 13.16 μm, and the highest mycelial growth was recorded on CMA. PCR analysis (ITS1/ITS4 and EF1-728F/EF-2) confirmed the presence of fragments of the expected size (~500 bp) in all isolates. The results confirm the presence of A. alternata on geranium in Serbia and emphasize the importance of timely identification for disease management
Strain AB3-4 featured brownish-green centers, white peripheral mycelium, darker central reverse fading radially, and based on morphology and phylogenetic pattern, AB3-4 was identified as Alternaria sp.
Qirui Zhang, Hai-Jiao Yang, Zhong-Shun Mao et al.· Plant Disease· 0 citations
Alternaria leaf spot caused by Alternaria alternata affects Ocimum basilicum L. worldwide, yet its occurrence and impact in Serbia have remained unknown. This study identified the causal agent of leaf spot on O. basilicum cv. Genovese using molecular, morphological, and pathogenic analyses, and assessed the effects of disease and meteorological conditions on herb yield and morphometric traits. From 109 sampled plants in the preliminary survey (2021 and 2022) and field experiment (2023–2025), 59 isolates were obtained from symptomatic leaves, stems, branches, and seeds. Isolates were preliminarily identified based on the ITS rDNA region. Pathogenicity tests were done on detached leaves, stems, and seedlings. For selected A. alternata isolates, identification was confirmed based on additional regions (Alt a1, ATP, and CAL) and morphology (PDA, PCA, and V8 media), while pathogenicity was confirmed on whole plants. Disease incidence varied from 0% (2023) to 34.87% (2024) under warm and favourable moisture conditions. Significant reductions in plant height, plant weight, number of branches, and leaf size indicated the combined effects of disease and unfavourable meteorological conditions, while dry herb yield was reduced by up to 59.8%. Temperature and precipitation between harvests played a key role in disease development and yield loss. This study provides the first comprehensive molecular, morphological, and pathogenic characterization of A. alternata causing basil leaf spot in Serbia and demonstrates the importance of climate–disease interactions for basil production. These findings provide a basis for targeted disease monitoring, early detection, and climate-informed disease management strategies. Future studies should validate these findings in additional basil cultivars and production environments.
Sara Gojković, Nina Vučković, Ivana Vico et al.· Horticulturae· 0 citations
The natural occurrence of Pedilanthus leaf curl virus and a novel Radish leaf curl Layyah betasatellite infecting radish in Pakistan are documents and underscore the occurrence of begomovirus with new betasatellite complexes in the region and highlight the need for continuous surveillance strategies to safeguard radish cultivation.
Muhammad Hassan, Muhammad Mubin, A. Jamil et al.· The Journal of Animal and Pl...· 0 citations
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