Search Results (33)

Pomegranate heart rot (black heart) was observed in several pomegranate-growing areas of Algeria. From 2022 to 2025, surveys were conducted across 15 provinces (20 localities), and a total of 85 fruits (symptomatic and asymptomatic) were collected. Fruits were cut transversely to assess internal symptoms, ranging from early aril browning to dry black rot. Thirty Alternaria isolates were obtained and grouped into four morphotypes based on colony and conidial morphological traits. A subset of 18 isolates was analysed by multilocus phylogeny (ITS, EF-1α, GAPDH and OPA10-2); all analysed isolates clustered within the Alternaria alternata species complex, in the clade including the ex-type strain CBS 916.96. Fruit pathogenicity tests with Algerian isolate GA reproduced typical internal heart rot symptoms, and the pathogen was consistently re-isolated from symptomatic tissues. In fruit inoculations with isolate GA, cultivars differed in susceptibility, with mean disease severities of 94%, 62% and 9.5% in ‘Taferrante’, ‘Ikhessène’ and ‘Kares’, respectively, expressed as the percentage of the fruit section presenting rot symptoms. Detached leaf assays indicated isolate-dependent differences in aggressiveness, and ‘Kares’ showed the lowest susceptibility. Overall, the results confirm that A. alternata is the causal agent of pomegranate heart rot in Algeria and provide baseline information for disease diagnosis and management. Full article

The objective of this study was to evaluate the preharvest application of γ-aminobutyric acid (GABA), melatonin (MT), and oxalic acid (OA), at different concentrations and application frequencies, on the physicochemical and microbiological quality of dried figs (cv. Calabacita) at commercial harvest and after 3 and 6 months of refrigerated storage. A further aim was to determine their impact on fungal populations and mycotoxin production. The results showed that untreated dried figs had a higher frequency of Aspergillus welwitschiae, A. tubingensis, and Aspergillus section Flavi, whereas elicitor-treated figs exhibited a lower incidence of toxigenic fungi. A. welwitschiae was the main ochratoxin A (OTA)-associated species detected, although the proportion of OTA-positive figs was lower in elicitor-treated samples than in the control. Aflatoxins (AFs) were detected only sporadically in 2 mM OA treatments, consistent with the limited activity of A. flavus at low storage temperatures. Conversely, Penicillium spp. were widespread but were associated with citrinin (CIT) production only under 2 mM OA treatments. Among the Alternaria toxins, alternariol (AOH) was detected solely in dried figs treated with 1 mM OA. Notably, all investigated mycotoxins were below the limit of detection (<LOD) in dried figs treated with 0.5 mM MT. Moderate elicitor concentrations (e.g., 0.5 mM MT and 50 mM GABA) and multiple preharvest applications generally provided the best balance between fungal suppression and fruit quality, significantly reducing Aspergillus spp. occurrence without promoting the growth of undesirable species. Overall, elicitor treatments decreased the incidence of toxigenic fungi, most likely through direct antifungal effects in senescent dried fruit rather than by inducing host defences. The combined use of preharvest elicitors with appropriate drying and storage conditions is a promising strategy to control fungal contamination and mycotoxin accumulation in dried figs while maintaining quality from preharvest storage. Further research is needed to optimise elicitor concentrations and application timing. Full article

Alternaria alternata is a common postharvest mold affecting tomato products, including cherry tomatoes, and causing their contamination with mycotoxins. When consumers encounter moldy fruits, some may remove the visibly contaminated part and consume the rest, to reduce waste. However, the extent to which A. alternata toxins migrate beyond visible fungal growth remains unclear, potentially posing health risks. This study investigated (i) the within-fruit migration of A. alternata in cherry tomatoes together with the associated mycotoxin production, and (ii) the diffusion of purified Alternaria toxins in tomatoes in the absence of any fungal activity. Toxins were quantified using LC-MS/MS, while fungal colonization was assessed through visual inspection and DNA quantification across fruit sections. In the absence of fungal growth, toxins remained largely confined to the spiking site and were degraded over time. In contrast, in inoculated samples, Alternaria DNA was detected at notable levels even in sections lacking visible fungal growth, while Alternaria toxins were found both in these regions and in lower fruit sections where fungal DNA was below the qPCR detection limit. These findings highlight the limitations of relying solely on visual inspection to assess food safety. A consumer recommendation is proposed to help minimize health risks while reducing food waste. Full article

Alternaria is a widespread genus and a diverse taxonomic group of fungi, whose members exhibit a wide range of ecological roles, from endophytes and saprophytes to potent plant pathogens, and in some cases, to opportunistic pathogens or allergens affecting humans. Their high adaptability to various environmental conditions determines their widespread distribution and resilience. A key feature of the genus Alternaria is its substantial species diversity. According to the Species Fungorum database, it currently comprises 792 registered species, which are grouped into 29 sections. It should be noted that this number reflects the current state of taxonomic classification and is subject to ongoing revision. The ecological role of representatives of this genus is particularly relevant in the context of agriculture, as many species are pathogens and causative agents of Alternaria leaf spot in important agricultural plants such as tomatoes, potatoes, apples, wheat, and others. This disease causes significant economic losses. At the same time, some strains demonstrate potential for use in biotechnology due to their ability to produce biologically active metabolites. This review examines the taxonomy, morphological characteristics, ecological role, pathogenicity, and control methods of fungi of the genus Alternaria, as well as their biotechnological potential. Full article

Essential oils (EOs) are promising bio-preservatives for oilseeds; however, their high volatility and strong aroma limit practical applications. In this study, we developed a dual-size microencapsulated formulation of oregano (Origanum compactum) and myrtle (Myrthus communis) EOs (75:25, w/w) using gelatin–gum arabic complex coacervation, and evaluated its antifungal efficacy and effect on seed viability in peanuts. GC-MS analysis of the EO blend identified carvacrol (33.83%) as the dominant constituent. The microcapsules exhibited an encapsulation efficiency of 83.56% and were produced in a 70% small/30% large particle ratio to ensure both immediate and sustained vapor release. In vapor-phase assays against toxigenic A. flavus (RP-6), both free and encapsulated EOs inhibited fungal growth in a dose-dependent manner and achieved complete suppression at concentrations ≥0.2 µL mL⁻¹, whereas the wall material alone showed no activity. In a 120-day microcosm storage experiment (0.2 mg EO g⁻¹ kernels; 0.96 mg microcapsules g⁻¹), treated peanuts showed an immediate reduction in total fungal load from 3.52 to 1.48 log₁₀ CFU g⁻¹ (≈58%), which stabilized near 1.42–1.43 log₁₀ CFU g⁻¹ up to 90 days, while the control samples increased to 4.25 log₁₀ CFU g⁻¹ by day 120. The formulation effectively suppressed major storage fungi, including Aspergillus sections Flavi and Nigri, Penicillium spp., Rhizopus, Fusarium, and Alternaria. The antioxidant activity (DPPH assay) was retained after encapsulation (IC₅₀: 0.52 mg mL⁻¹ encapsulated vs. 0.58 mg mL⁻¹ free). Germination power remained comparable to the control throughout storage (≈50–52%), indicating no adverse impact on seed viability. These findings demonstrate that vapor-active, dual-size microencapsulation of oregano-myrtle EOs offers a practical and sustainable approach to enhance peanut safety during storage without compromising germination potential. Full article

Allergen sensitization profiles are increasingly affected by environmental and climate changes. This study exemplifies fundamental differences in molecular IgE sensitization profiles in two nearby regions in Argentina with different climatic conditions (La Plata and Bahía Blanca). A cross-sectional study was conducted involving 155 patients with allergic symptoms from La Plata and Bahía Blanca (34.0 ± 11.2 years, female/male: 83/72). Serum samples were analyzed for IgE reactivity using a chip containing 101 micro-arrayed allergen molecules. Statistical analyses were performed to compare allergen-specific IgE levels, sensitization prevalences and reported symptoms. Patients from La Plata—with subtropical weather—showed a higher prevalence of IgE reactivity to house dust mite (HDM) allergens (Der p 23: 74%; Der p 1: 53% and Der p 2: 56%) and more frequently reported asthma (AS) symptoms (40% vs. 24%) than patients from Bahía Blanca. In contrast, patients from Bahía Blanca, with dry and windy weather, exhibited higher sensitization rates to pollen allergens, particularly Phl p 1 (49%) and Ole e 1 (22%) as well as to Alternaria alternata (Alt a 1, 35%) and reported a significantly higher prevalence of skin manifestations (54% vs. 31%) than those from La Plata. Cat allergen Fel d 1 was an equally important sensitizer in both regions (La Plata 30% and Bahía Blanca 37%). Sensitization to class 1 food allergens was rare in both groups (1–8%), including non-specific lipid transfer proteins (peanut Ara h 9 and peach Pru p 3) but IgE sensitizations to genuine peanut allergens were almost absent. Important regional differences in allergen sensitization profiles were observed between two geographically close regions with different climatic conditions. Our findings underscore the relevance of region-specific allergen profiling and highlight the clinical utility of molecular allergy diagnosis for a more precise allergen identification and improved management of allergic diseases. Full article

Almonds are an essential crop for the economy of California. However, mold and mycotoxin contamination of this commodity has a serious impact on food safety and international trade. The contamination levels of molds and the aflatoxigenic potential of Aspergillus section Flavi isolates were studied on almonds collected at a processing plant in California. The mean total fungal count for 80 samples was 1.0 × 10⁴ CFU/g, while 62 samples (77.5%) had a total mold count less than 1.0 × 10⁴ CFU/g. The most common fungal contaminants were Aspergillus section Nigri (100% of samples), followed by Penicillium (57.5%) and Cladosporium (52.5%) species. Rhizopus, Fusarium and Alternaria spp. were less frequent. A total of 26 A. section Flavi strains were identified, with most strains (23) belonging to the L morphotype of A. flavus. In addition, two S morphotypes of A. flavus, and one A. tamarii strain were observed. Other Aspergillus species, including A. terreus and A. ochraceus were rare. High Performance Liquid Chromatography (HPLC) analysis revealed that 9 out of 13 isolated A. flavus strains produced aflatoxin B₁ (AFB₁) on yeast extract sucrose media. The highest levels of AFB₁ were produced by two A. flavus isolates belonging to the S morphotype (78 and 260 µg/kg). Increasing temperatures and drought conditions may change the population dynamics of toxigenic mold strains on almonds, emphasizing the need to continue monitoring these fungal populations. Full article

The locoweeds Astragalus and Oxytropis in the Americas and China, as well as Swainsona in Australia, harbor swainsonine-producing endophytes responsible for “locoism” or “pea struck” syndromes in grazing animals. Demonstration of Alternaria section Undifilum spp. requires demonstration of morphological characters such as a wavy germ tube and slow growth. While Astragalus wetherilli, A. pubentissimus, Swainsona canescens, and S. galegifolia plants have been shown to contain swainsonine, and fungi isolated from the plants have been partially characterized genetically, the fungi have not been characterized morphologically. This work sought to complete morphological characterization and determine species for those fungi and from fungi associated with Swainsona luteola and S. brachycarpa. The fungi were isolated from their hosts onto media and exhibited slow growth, resulting in a colony diameter of approximately 10 mm after 30 days. Morphological identification revealed production of conidia that produced a wavy germ tube for the endophytes from Astragalus pubentissimus species, Swainsona canescens, and S. galegifolia. Sequence analyses of the ITS region and the swnK-KS and swnK-TR genes of these fungi suggest that the fungi isolated from Astragalus are closely related and distinct from the fungi isolated from Swainsona. Presence of the swnK gene demonstrates that all the fungi have a necessary component to produce swainsonine. Fungi isolated from Astragalus spp. differed in color, growth, and conidium size, and/or their sequences. While the fungi isolated from Swainsona canescens and S. galegifolia endophytes differed in color, growth, and conidium size, those isolated from Swainsona luteola and S. brachycarpa did not produce conidia. Sequences from all Swainsona endophytes were almost identical and were concluded to be the same species. The new species described here are Alternaria wetherii, A. pubentissima, A. pubentissimoides, and A. swainsonii. Full article

Alternaria species are important fungal pathogens occurring worldwide in wheat, causing both productive and qualitative losses, and posing a toxicological risk to human health due to the production of their mycotoxins in kernels. This study aimed to investigate the occurrence of Alternaria species and their mycotoxins in 48 wheat grain samples collected from the northeast to the southeast of Algeria. Seventy-two representative Alternaria strains were molecularly analyzed using a multi-locus sequence approach and evaluated for their capability to produce mycotoxins under in vitro conditions. Alternaria alternata, representing 42% of the strains, was the dominant species, followed to a lesser extent by species included in the Infectoriae section (26%). In addition, three species not previously reported in Algerian wheat, A. eureka, A. consortialis and A. tellustris, were identified, accounting for 5% of the total strains. Mycotoxin analyses showed high contamination of grains with alternariol monomethyl ether, alternariol and tenuazonic acid, occurring in 75, 69 and 35% of the samples, respectively. Moreover, 41 out of 48 samples showed the co-occurrence of multiple Alternaria mycotoxins. This study provides, for the first, time a clear picture of the occurrence and the distribution of Alternaria species on wheat in Algeria. Finally, the extensive monitoring activities carried out revealed the great biodiversity of Alternaria species able to colonize wheat grains. Moreover, findings on mycotoxin contamination raise concerns about the significant mycotoxigenic risk in Algerian wheat, emphasizing the need for strict monitoring and regulatory measures on Alternaria mycotoxins in food and feed. Full article

Alternaria is a large genus of fungi comprising approximately 400 species, currently classified into 29 sections. These fungi exhibit a cosmopolitan distribution, thriving in both natural and human-impacted environments with saprophytic, endophytic, and parasitic lifestyles. As part of our ongoing studies on fungi associated with wetland plants in the families Cyperaceae and Juncaceae across various regions of Iran, we isolated 21 fungal strains displaying morphological traits of Alternaria. Multigene phylogenetic analysis and morphological examination of eight selected strains confirmed their placement within Alternaria with strong support. These isolates formed a basal clade distinct from the 29 previously recognized sections and six monotypic lineages, leading to the establishment of a new section, Alternaria section Iraniana, to accommodate them. Furthermore, two monophyletic lineages within this section were identified, representing two new species, A. avrinica and A. iraniana, which are described and illustrated in this study. The new section is distinguished by long, semi-macronematous to macronematous conidiophores with multiple geniculate and sympodial proliferations, as well as solitary, non-beaked conidia that have only transverse eu-septa to pseudo-septa. The newly described species are differentiated based on conidiophore and conidial characteristics and nucleotide sequence comparisons of genomic regions. These results contribute to a better understanding of the distribution and host range of Alternaria species, while highlighting the importance of ongoing research into fungal taxonomy and biodiversity in Iran, a region rich in potential for the discovery of new fungal species. Full article

Alternaria includes endophytes, saprophytes, and pathogens affecting both plants and animals, with a global distribution across various hosts and substrates. It is categorized into 29 sections, each defined by a type species and six monophyletic lineages. The Alternaria section Nimbya comprises 10 species primarily associated with the families Juncaceae and Cyperaceae, functioning as either saprophytes or plant pathogens. In this study, 189 fungal strains were collected from multiple locations across six provinces in Iran. The isolates were initially classified based on morphological characteristics and ISSR-PCR molecular marker banding patterns. Multi-gene phylogenetic analyses of 38 selected strains, using ITS–rDNA, GAPDH, TEF1, RPB2, and Alt a 1 gene sequences, combined with morphological data, led to the identification of 13 species, including eight new species, namely Alternaria caricifolia, A. cyperi, A. juncigena, A. junci-inflexi, A. persica, A. schoenoplecti, A. salkadehensis, and A. urmiana. In addition, this work identified new host associations (matrix nova) for three previously known species: A. caricicola on Cyperus sp., A. cypericola on Eleocharis sp., and A. junci-acuti on Carex sp. The study provides detailed morphological descriptions and illustrations of all identified species, discusses their habitats, distribution, and phylogenetic relationships within section Nimbya, and presents a key for species identification within this section in Iran. Furthermore, these findings highlight the significance of studying fungal biodiversity in Iran and contribute to a better understanding of species distribution and host range within the Alternaria section Nimbya. Full article

Aspergilli and other molds are prevalent in the environment and are an important cause of opportunistic infections and seasonal allergies in susceptible patients. This study determined species distribution of various molds in outdoor/indoor air in and around a major hospital and performed antifungal susceptibility testing and molecular fingerprinting of environmental and clinical Aspergillus fumigatus isolates in Kuwait. Sampling for the isolation of molds was performed for a 17-month-period from the water/indoor air of medical/surgical wards/ICUs and outdoor air. Molds were identified by phenotypic characteristics and/or by the PCR-sequencing of rDNA/β-tubulin/calmodulin genes. Antifungal susceptibility testing was done by Etest. Fingerprinting was performed by nine-loci-based microsatellite analysis. A total of 6179 isolates were obtained from outdoor (n = 4406) and indoor (n = 1773) environments. These included Cladosporium spp. (n = 2311), Aspergillus spp. (n = 1327), Penicillium spp. (n = 1325), Paecilomyces spp. (n = 473), Alternaria spp. (n = 218), Bipolaris spp. (n = 133), and other molds (n = 392). Fingerprinting data revealed heterogeneity among clinical and environmental A. fumigatus and shared genotypes among outdoor air and hospital environmental isolates. Itraconazole-resistant A. fumigatus isolates with TR₃₄/L98H mutations in Cyp51A were also recovered from outdoor air (n = 1), a hospital environment (n = 3), and clinical samples (n = 2). More than 15 fungal genera and all four Aspergillus (Nigri, Flavi, Fumigati, and Terrei) sections and nine rare aspergilli were detected. The isolation frequency was higher during the peak allergy season of October/November. The presence of shared genotypes among outdoor air and the hospital environment including triazole-resistant A. fumigatus suggests a reservoir for invasive infections among susceptible hospitalized patients. Full article

Artificial intelligence techniques are now widely used in various agricultural applications, including the detection of devastating diseases such as late blight (Phytophthora infestans) and early blight (Alternaria solani) affecting potato (Solanum tuberorsum L.) crops. In this paper, we present a mobile application for detecting potato crop diseases based on deep neural networks. The images were taken from the PlantVillage dataset with a batch of 1000 images for each of the three identified classes (healthy, early blight-diseased, late blight-diseased). An exploratory analysis of the architectures used for early and late blight diagnosis in potatoes was performed, achieving an accuracy of 98.7%, with MobileNetv2. Based on the results obtained, an offline mobile application was developed, supported on devices with Android 4.1 or later, also featuring an information section on the 27 diseases affecting potato crops and a gallery of symptoms. For future work, segmentation techniques will be used to highlight the damaged region in the potato leaf by evaluating its extent and possibly identifying different types of diseases affecting the same plant. Full article

Endophytes are essential in plant succession and evolution, and essential for stress resistance. Coralloid root is a unique root structure found in cycads that has played a role in resisting adverse environments, yet the core taxa and microbial community of different Cycas species have not been thoroughly investigated. Using amplicon sequencing, we successfully elucidated the microbiomes present in coralloid roots of 10 Cycas species, representing all four sections of Cycas in China. We found that the endophytic bacteria in coralloid roots, i.e., Cyanobacteria, were mainly composed of Desmonostoc_PCC-7422, Nostoc_PCC-73102 and unclassified_f__Nostocaceae. Additionally, the Ascomycota fungi of Exophiala, Paraboeremia, Leptobacillium, Fusarium, Alternaria, and Diaporthe were identified as the core fungi taxa. The Ascomycota fungi of Nectriaceae, Herpotrichiellaceae, Cordycipitaceae, Helotiaceae, Diaporthaceae, Didymellaceae, Clavicipitaceae and Pleosporaceae were identified as the core family taxa in coralloid roots of four sections. High abundance but low diversity of bacterial community was detected in the coralloid roots, but no significant difference among species. The fungal community exhibited much higher complexity compared to bacteria, and diversity was noted among different species or sections. These core taxa, which were a subset of the microbiome that frequently occurred in all, or most, individuals of Cycas species, represent targets for the development of Cycas conservation. Full article

The indolizidine alkaloid-swainsonine (SW) is the main toxic component of locoweeds and the main cause of locoweed poisoning in grazing animals. The endophytic fungi, Alternaria Section Undifilum spp., are responsible for the biosynthesis of SW in locoweeds. The swnK gene is a multifunctional complex enzyme encoding gene in fungal SW biosynthesis, and its encoding product plays a key role in the multistep catalytic synthesis of SW by fungi using pipecolic acid as a precursor. However, the transcriptional regulation mechanism of the swnK gene is still unclear. To identify the transcriptional regulators involved in the swnK gene in endophytic fungi of locoweeds, we first analyzed the upstream non-coding region of the swnK gene in the A. oxytropis UA003 strain and predicted its high transcriptional activity region combined with dual-luciferase reporter assay. Then, a yeast one-hybrid library of A. oxytropis UA003 strain was constructed, and the transcriptional regulatory factors that may bind to the high-transcriptional activity region of the upstream non-coding region of the swnK gene were screened by this system. The results showed that the high transcriptional activity region was located at −656 bp and −392 bp of the upstream regulatory region of the swnK gene. A total of nine candidate transcriptional regulator molecules, including a C2H2 type transcription factor, seven annotated proteins, and an unannotated protein, were screened out through the Y1H system, which were bound to the upstream high transcriptional activity region of the swnK gene. This study provides new insight into the transcriptional regulation of the swnK gene and lays the foundation for further exploration of the regulatory mechanisms of SW biosynthesis in fungal endophytic locoweeds. Full article