The pathogen was identified as Truncatella angustata, representing the first report of this species causing leaf spot on strawberry in China, and providing a basis for accurate diagnosis and targeted management strategies for this emerging strawberry disease.
Abstract
Strawberry (
Fragaria × ananassa
Duch.) is an economically important fruit crop widely cultivated in China, yet its production is frequently constrained by fungal diseases. During field surveys in Xinjiang, symptoms of an unreported brown leaf spot were observed on strawberry plants. This study aimed to identify the causal agent, characterize its morphology and phylogeny, and evaluate its sensitivity to commonly used fungicides. Fungal isolates obtained from symptomatic leaf tissues were subjected to morphological observation and multilocus phylogenetic analysis based on the internal transcribed spacer (ITS) region, the large subunit ribosomal RNA gene (LSU), and the second‐largest subunit of RNA polymerase II (
rpb2
). Pathogenicity was confirmed through inoculation of healthy strawberry leaves following Koch's postulates. Fungicide sensitivity was assessed by measuring mycelial growth inhibition on amended media. The pathogen was identified as
Truncatella angustata
, representing the first report of this species causing leaf spot on strawberry in China. Among the fungicides tested, 40% difenoconazole·pyraclostrobin SC, 25% difenoconazole·pyraclostrobin WG, 30% azoxystrobin·pentaconazole SC and 25% pyrimethanil SC exhibited the strongest inhibitory effects on mycelial growth. These findings provide a basis for accurate diagnosis and targeted management strategies for this emerging strawberry disease.
The findings provide a theoretical foundation for accurate disease diagnosis, epidemiological surveillance, and the development of effective chemical control strategies for rubber plantations.
Zhiying Cai, Lili He, Li-Ming Dai et al.· Plants· 0 citations
Yellow leaf disease (YLD) is a destructive disease of arecanut (Areca catechu L.) that is associated with progressive yellowing, root deterioration, reduced nut production, and palm decline. This study compared culturable rhizosphere fungal populations in healthy and YLD-affected arecanut gardens and characterised the isolates using morphological and molecular methods. Twenty-five rhizosphere soil samples were processed using serial dilution plating on rose bengal agar. Fungal colonies were purified on potato dextrose agar, and genomic DNA was extracted. The internal transcribed spacer region was amplified using ITS-1 and ITS-4 primers, sequenced, and analysed through BLAST searches against the NCBI nucleotide database. Healthy rhizosphere soils contained higher populations of beneficial microorganisms than disease-affected soils. Trichoderma species were predominant, particularly T. asperellum and T. harzianum, while Fusarium, Talaromyces, Gibberella, and Diaporthe taxa were also identified. The abundance of Trichoderma isolates in healthy soils was consistent with their recognised associations with root development, nutrient mobilisation, water uptake, and suppression of soil-borne pathogens. The study demonstrates an association between palm health and the composition of culturable rhizosphere fungi and provides a basis for further functional and culture-independent investigations of the arecanut rhizosphere.
K. Premalatha, B. G. Naik, K. Hariprasad et al.· Journal of Advances in Biolo...· 0 citations
Background: Botrytis cinerea gray mold is one of the most significant diseases that limits strawberry productivity under field and postharvest conditions. It is essential to accurately identify the pathogen and examine potential control options to develop effective disease-management strategies. Objective: This study aimed to isolate and identify Botrytis cinerea associated with gray mold of strawberry, validate representative isolates through ITS-rDNA sequencing, determine their pathogenicity, and perform an in vitro assessment of the efficacy of selected fungicides, antagonistic microorganisms (AMO) and botanical extracts. Methodology: From Dec. 2024 to Mar. 2025, symptomatic strawberry samples were collected from various growing areas of northern Iraq. Isolation of the fungal isolates was performed on potato dextrose agar and subsequently purified with the hyphal-tip technique. Identification was performed first through colony and microscopic characteristics, then confirmed with pathogenicity tests and amplifying the internal transcribed spacer region of ribosomal DNA (ITS-rDNA) using primers ITS1 and ITS4. PCR products were sequenced, compared with reference sequences in the NCBI database using BLAST and analyzed phylogenetically using MEGA. In vitro evaluations were conducted to assess the inhibitory effects of selected fungicides, microbial antagonists, and plant extracts. Data were analyzed by analysis of variance and means compared using Tukey's test at p < 0.05 when appropriate. Results: B. cinerea was confirmed in infected strawberry tissues by morphology determination and pathogenicity test. ITS-rDNA sequencing of representative isolates revealed significant homology with reference B. cinerea sequences found in GenBank, and phylogenetic analysis confirmed that the tested isolates fell within the B. cinerea group. Isolates evaluated differed in virulence. In vitro, all tested fungicides decreased fungal growth, compared to the control with dicarboximide having the lowest EC50 followed by benzimidazole and then other fungicides. Biological Control Trichoderma spp. showed the highest antagonistic activity. The botanical extracts tested also inhibited the growth of fungi, and all separated these 12 strains into three antifungal bands; Allium sativum had the maximum antifungal effect, followed by Mentha spicata and Tagetes patula, Asystasia gangetica & Syzygium cumini & Rosmarinus officinalis & Achillea millefolium. Conclusion: Based on the results obtained, the current study concluded the presence of abnormally shaped colonies through a multi-faceted approach that included pathogenesis tests and ITS-rDNA sequencing to provide accurate identification of gray mold in strawberries (Botrytis cinerea). The study demonstrated significant variability among the isolates, highlighting the importance of accurate pathogen identification before implementing control measures. The results indicate that dicarboxymides, Trichoderma species, and garlic extract (Allium sativum) were the most effective chemical, biological, and phytochemical treatments, respectively. These findings support the feasibility of integrated management approaches that combine biological, phytochemical, and conventional fungicides for controlling gray mold in strawberries.
Ahmed R. Alsharmani, Ali Marzooq Salman, Hawraa Razzaq Dhaher ALaboudi et al.· International Journal of Env...· 0 citations
In vitro fungicide sensitivity assays, performed using the hyphal growth inhibition method against six common fungicides, demonstrated that Carbendazim was the most effective agent, indicating significant selectivity.
Fang Wu, Jing Tu, Zhu-xiang Liu et al.· Plant Disease· 0 citations
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
F. Elahi, M. M. Hasan, Monirul Islam et al.· Asian-Australasian journal o...· 0 citations
Late blight disease remains one of the major constraints affecting tomato production worldwide due to its rapid spread and destructive effects on infected plants. This study was undertaken to isolate and identify microorganisms associated with late blight disease of tomato plant in Niger state. A total of thirty diseased tomato samples showing symptoms of late blight were collected from selected tomato farmlands from Bida, Lapai and Agaie Local Government Area of Niger State, Nigeria. The samples were analyzed using standard microbiological and biochemical techniques. Fungal isolates were identified based on their cultural and microscopic characteristics, while bacterial isolates were identified using biochemical tests. The fungi isolated included Phytophthora infestans (40.0%), Alternaria solani (25.3%), Fusarium oxysporum (18.7%), Aspergillus flavus (10.7%), and Phoma destructiva (5.3%). The bacterial isolates recovered were Pseudomonas syringae (38.5%), Xanthomonas campestris (30.8%), Ralstonia solanacearum (20.5%), and Bacillus subtilis (10.2%). Phytophthora infestans and Pseudomonas syringae were the most predominant fungal and bacterial isolates, respectively. The findings of this study indicate that late blight-infected tomato plants harbor diverse fungal and bacterial species that may collectively contribute to disease severity and tissue deterioration. The study therefore emphasizes the importance of accurate identification of microorganisms associated with tomato diseases for effective disease monitoring and management in tomato production.
Aisha Abubakar, Maikudi Habiba Mohammed· The Scientific World Journal· 0 citations
