Browsing by Author "Dervis, Sibel"

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Alternaria Alternata Causing Inner Black Rot of Lemon (Citrus Limon) Fruits in Turkey: Genetic Diversity and Characterisation
(Academic Press Ltd- Elsevier Science Ltd, 2023) Gunen, Tacettin Utku; Ozer, Goksel; Dervis, Sibel; Guney, Inci Guler; Tekin, Fatih
The market sales of symptomless lemons in 2020 revealed a persistent and severe internal black rot with browning of the membrane wall and juice sac. To investigate the causal agent, externally symptom-free lemons from Mediterranean locations were sampled from supermarkets, local markets, and bazaars in three southeastern Turkish provinces. Internal black rot symptoms were observed in 13.69% of the 1300 externally symptomless fruits, and Alternaria was isolated from 96.63% of those exhibiting these symptoms. Morphological analysis confirmed the identity of Alternaria alternata in 26 representative isolates collected from various markets and bazaars. To examine genetic diversity or polymorphisms, start codon targeted (SCoT) markers were used. Species identification was based on the sequences of translation elongation factor 1-alpha (TEF 1-alpha), RNA polymerase second largest subunit (RPB2), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). SCoT 29 exhibited the highest amount of polymorphic amplicons, with 18 polymorphic bands scored when compared to the other six scoreable markers. The 26 representative isolates from various markets and bazaars were divided into four clades by SCoT 29. However, multilocus sequence analyses confirmed the identification of a single species, A. alternata. In terms of virulence and the impact of temperature on growth, representative isolates from four SCoT clusters were evaluated. Data suggests that SCoT markers can be used to evaluate virulence-based polymorphism in A. alternata; nonetheless, all clades showed comparable temperature responses, with 25 degrees C being the optimum. There was also no association between individual morphotypes and SCoT clade membership. Due to the lack of obvious signs on lemon fruits, producers, merchants, and consumers are unable to identify black rot, and the widespread presence of A. alternata in lemons may pose a significant risk that must be avoided at all costs.
Citation - WoS: 6
Citation - Scopus: 5
Armillaria Species Causing Kiwifruit Vine Decline and Root Rot in Northeastern Türkiye: a Growing Concern for Kiwifruit Health
(Wiley, 2024) Turkkan, Muharrem; Bozoglu, Tugba; Dervis, Sibel; Erper, Ismail; Ozer, Goksel
Kiwifruit (Actinidia deliciosa) production in northeastern T & uuml;rkiye is facing an emerging threat from Armillaria root rot. Surveys conducted in August 2021 and 2022 revealed that 10.5%-17.5% of the 200-500 vines within each of 35 kiwifruit orchards in the Per & scedil;embe, G & uuml;lyal & imath; and Alt & imath;nordu districts of Ordu province exhibited symptoms of Armillaria root rot, including complete defoliation. Diseased plants exhibited diagnostic signs on their root collars and woody roots, including white mycelial fans, extensive wood rot and rhizomorphs. A single Armillaria isolate was obtained from each of the 35 symptomatic orchards. Molecular identification, employing DNA sequencing of the large subunit (LSU) region of rDNA, the translation elongation factor subunit 1-alpha (TEF1) gene and the second largest RNA polymerase II B-subunit (RPB2) gene, identified 20 isolates as Armillaria gallica and 15 as A. mellea. Phylogenetic analyses, based on TEF1 alignments, further supported the species identification with a 100% bootstrap value. To examine genetic diversity, start codon targeted (SCoT) marker 13 was used, successfully differentiating the two Armillaria species and revealing three distinct clades. Clades I and II comprised 15 and 5 isolates of A. gallica, respectively, while Clade III contained all 15 A. mellea isolates. Pathogenicity testing on kiwifruit seedlings (cv. Hayward) revealed the ability of both A. gallica and A. mellea isolates to induce disease. Rhizomorph-producing isolates in kiwifruit seedlings displayed high virulence, inducing severe leaf necrosis and seedling mortality, while isolates lacking these structures were non-pathogenic. This study identifies the first global instance of A. gallica causing kiwifruit root rot. This finding, along with the identification of A. mellea as a causal agent in the country, highlights the emerging threat of Armillaria root rot to kiwifruit production in the region.
Armillaria Species Causing Kiwifruit Vine Decline and Root Rot in Northeastern Turkiye: a Growing Concern for Kiwifruit Health (Vol 172, E13409, 2024)
(Wiley, 2025) Turkkan, Muharrem; Bozoglu, Tugba; Dervis, Sibel; Erper, Ismail; Ozer, Goksel
Citation - WoS: 1
Citation - Scopus: 1
Carbonates and Bicarbonates: a Sustainable Approach for Managing Plant Diseases, Pests, and Abiotic Stresses
(Academic Press Ltd- Elsevier Science Ltd, 2025) Turkkan, Muharrem; Ozer, Goksel; Taheri, Parissa; Dervis, Sibel
The growing global food demand necessitates sustainable agricultural practices that minimize environmental impact while ensuring high yields. Synthetic pesticides, while crucial for crop protection, raise concerns about environmental contamination, resistance development, and harm to non-target organisms. Carbonates and bicarbonates (e.g., NaHCO3, KHCO3, CaCO3) offer a promising, Generally Recognized as Safe (GRAS) alternative for integrated pest and disease management and abiotic stress mitigation. These compounds exhibit broadspectrum efficacy against diverse fungal, oomycete, bacterial, and insect pathogens, including the clubroot protist (Plasmodiophora brassicae). Their direct antimicrobial mechanisms involve disrupting pathogen cell membranes and walls, inducing osmotic stress, and altering pH, which leads to pathogen death. Beyond direct toxicity, carbonates and bicarbonates also elicit plant defenses, inducing systemic acquired resistance (SAR) and stimulating defense enzymes (e.g., peroxidase, polyphenol oxidase). Furthermore, they enhance soil health by raising pH, improving nutrient availability, structure, and water retention, while reducing heavy metal bioavailability. These soil improvements increase plant resilience to drought, salinity, and metal toxicity, with potential benefits also arising from improved stomatal regulation. Recent advancements have introduced carbonate nanoparticles as nano-fungicides and biostimulants, offering enhanced efficacy at lower application rates. Integrating carbonates/bicarbonates into Integrated pest management (IPM) programs, especially in combination with biocontrol agents and other beneficial salts, demonstrates synergistic effects and reduces reliance on conventional pesticides. However, further research is needed to elucidate detailed molecular mechanisms, assess long-term soil impacts, optimize application methods (e.g., foliar sprays, soil amendments, nanoformulations), and evaluate compatibility with other agrochemicals. Addressing these knowledge gaps will enable the full potential of these sustainable compounds for resilient and food-secure agriculture.
Comparative Resistance of Barley and Wheat Germplasm to Common Root Rot Caused by Bipolaris Sorokiniana
(Kahramanmaras Sutcu Imam Univ Rektorlugu, 2026) Alkan, Mehtap; Korkulu, Serife Gul; Turkkan, Muharrem; Dervis, Sibel; Yuksel, Soner; Dababat, Abdelfattah A.; Ozer, Goksel
This study evaluated the resistance of 54 wheat and 14 barley cultivars in Bolu, and 6 wheat cultivars and 89 barley lines in Eski & scedil;ehir, to common root rot caused by Bipolaris sorokiniana under controlled conditions. Location-specific B. sorokiniana isolates (wheat-derived in Bolu, barley-derived in Eski & scedil;ehir) were employed for evaluation. In Bolu, wheat cultivars demonstrated tolerance with variable disease severity, while barley cultivars showed moderate susceptibility with significantly greater disease severity than wheat. Conversely, wheat cultivars in Eski & scedil;ehir exhibited complete resistance with no symptoms, whereas barley lines displayed responses ranging from complete resistance to high susceptibility. Eight wheat cultivars and two barley lines achieved complete resistance across both locations. Neither growth habit (spring vs. winter) in wheat nor row-type (two-row vs. six-row) in barley significantly influenced disease severity. The consistent difference in disease severity between barley and wheat, with barley exhibiting greater susceptibility, highlights the importance of targeted breeding efforts for each crop. Field evaluations are crucial to validate the findings under natural conditions and refine disease management strategies.
Etiology of Postharvest Fungal Decay in Kumquat: A Polyphasic Approach Integrating Aggressiveness, IPBS and SCOT Fingerprinting, and Multilocus Phylogeny
(Elsevier, 2026) Alkan, Mehtap; Ozer, Goksel; Turkkan, Muharrem; Bozoglu, Tugba; Erper, Smail; Yildirim, Elif; Dervis, Sibel; Erper, İsmail
As the global popularity of kumquat (Fortunella spp.; syn. Citrus japonica) continues to rise, knowledge of the pathogens responsible for postharvest losses remains limited. This study presents the first etiological investigation of postharvest fungal decay in kumquat, using a multi-regional survey and polyphasic characterization. A pathogenic complex responsible for postharvest decay was identified on this host for the first time, consisting of Alternaria alternata (n = 23), Geotrichum citri-aurantii (n =17), Penicillium digitatum (n = 30), P. italicum (n = 8), and P. expansum (n = 4). Identification combined morphological characterization with high-resolution molecular fingerprinting using start codon targeted (SCoT 32) and inter-primer binding site (iPBS 2395) markers, yielding polymorphic profiles that provided clear species-level discrimination consistent with multilocus phylogenetic analysis. In vitro assays identified distinct thermal optima for each pathogen. Geotrichum citri-aurantii growth was maximal at 30 degrees C, whereas P. expansum grew optimally at 20 degrees C. The remaining species-P. digitatum, P. italicum, and A. alternata-all achieved maximum growth at 25 degrees C, although P. italicum demonstrated a broad optimal range spanning from 20 to 25 degrees C. Aggressiveness varied among the pathogens, with P. digitatum and A. alternata being the most aggressive, followed by G. citri-aurantii and P. expansum, while P. italicum was the least aggressive. This study establishes the first pathogenic profile for kumquat decay, providing a framework for evidence-based postharvest management. The demonstrated efficiency of SCoT 32 and iPBS 2395 markers highlights their value as powerful, rapid, and cost-effective tools for pathogen surveillance and taxonomic resolution in postharvest pathology.
First Report of Alternaria Alternata Causing Leaf Spot on Catalpa Bignonioides in Türkiye
(Springer, 2026) Alkan, Mehtap; Ozer, Goksel; Bozoglu, Tugba; Dervis, Sibel; Turkkan, Muharrem
Citation - WoS: 2
Citation - Scopus: 2
First Report Of Colletotrichum Perseae Causing Anthracnose Disease of Avocado ( Persea Americana) in Türkiye
(Academic Press Ltd- Elsevier Science Ltd, 2024) Bozoglu, Tugba; Turkkan, Muharrem; Ozer, Goksel; Guney, Inci Guler; Dervis, Sibel
Colletotrichum-induced anthracnose is a major disease of avocado (Persea americana), causing significant losses in production worldwide. In 2023, a survey of avocado fruits in markets within the K & imath;z & imath;ltepe district of Mardin, T & uuml;rkiye, revealed symptoms of anthracnose, characterized by brown-black lesions and internal necrosis. To identify the causal agent, 20 symptomatic avocado fruits were collected and fungal isolates resembling Colletotrichum species were obtained. Morphological characterization, multilocus sequence analysis of the internal transcribed spacer (ITS), actin (act), the apn2-Mat1-2 intergenic spacer (ApMat), and calmodulin (cal) loci, and pathogenicity testing were performed for only two representative isolates (Pa01 and Pa02). These analyses identified the pathogen as Colletotrichum perseae. The isolates readily formed ascomata on all culture media tested, suggesting a high capacity for sexual reproduction. Pathogenicity tests confirmed that C. perseae caused characteristic dark, sunken anthracnose lesions on avocado fruits. This is the first report of C. perseae causing anthracnose in avocados in T & uuml;rkiye, expanding the known geographical distribution of this pathogen. The findings highlight the need for effective disease management strategies and further research to understand the pathogen's lifecycle, environmental conditions favoring infection, and potential for seedborne transmission.
Citation - WoS: 1
Citation - Scopus: 1
First Report of Fusarium Equiseti Causing Postharvest Fruit Rot of Avocado in Türkiye
(Wiley, 2025) Bozoglu, Tugba; Dervis, Sibel; Ozer, Goksel; Turkkan, Muharrem
In September 2024, postharvest fruit rot, including stem-end rot, was observed on avocado in the Alt & imath;nordu district of Ordu province, located in the Eastern Black Sea Region of T & uuml;rkiye. A market survey revealed that 5% of fruit exhibited fruit rot symptoms, a subset of which displayed stem-end rot symptoms, including brown to black lesions extending into the mesocarp, shrivelling and fungal mycelium growth. Fusarium equiseti was identified as the causal agent through morphological characterisation and molecular analysis using PCR amplification and sequencing of translation elongation factor 1-alpha (tef1) and RNA polymerase II second largest subunit (rpb2) gene sequences, including phylogenetic analysis. Artificial inoculation and subsequent re-isolation confirmed Koch's postulates, verifying F. equiseti as the causal pathogen. This is the first report of F. equiseti causing both fruit rot and stem-end rot on avocado in T & uuml;rkiye, highlighting the need for improved postharvest disease management strategies to reduce economic losses in T & uuml;rkiye's avocado industry.
First Report of Fusarium Nirenbergiae Causing Stem-End Rot on Avocado (Persea Americana) in Türkiye
(Springer, 2025) Ozer, Goksel; Alkan, Mehtap; Bozoglu, Tugba; Turkkan, Muharrem; Dervis, Sibel
First Report of Fusarium Solani Causing Wilt and Stem Rot on Lisianthus (Eustoma Grandiflorum) in Türkiye
(Springer, 2025) Polat, Zuhtu; Gultekin, Mehmet Akif; Gulbag, Fatih; Dervis, Sibel; Ozer, Goksel
Citation - WoS: 1
Citation - Scopus: 2
First Report of Neoscytalidium Dimidiatum Causing Dieback and Canker on Leyland Cypress in Türkiye
(Springer, 2025) Alkan, Mehtap; Ozer, Goksel; Dervis, Sibel
Citation - WoS: 5
Citation - Scopus: 5
First Report of Neoscytalidium Dimidiatum Causing Dieback, Shoot Blight, and Branch Canker of Willow Trees in Turkey
(Amer Phytopathological Soc, 2019) Turkolmez, Sahimerdan; Dervis, Sibel; Ciftci, Osman; Serce, Cigdem Ulubas; Turkohmez, Cemile Gulden; Dikilitas, Murat
Citation - WoS: 14
Citation - Scopus: 16
First Report of Neoscytalidium Dimidiatum Causing Shoot and Needle Blight of Pines (Pinus Spp.) in Turkey
(Amer Phytopathological Soc, 2019) Turkolmez, Sahimerdan; Dervis, Sibel; Ciftci, Osman; Dikilitas, Murat
Citation - WoS: 7
Citation - Scopus: 7
First report of Neoscytalidium novaehollandiae on common sage (Salvia officinalis)
(Springer link, 2021) Dervis, Sibel; Guney, Inci Guler; Kosar, Islim; Bozoglu, Tugba; Ozer, Goksel
In June 2020, many plants exhibited symptoms of root rot and foliar blight in the experimental field of common sage in Sanliurfa province, Turkey. The pathogen was identified as Neoscytalidium novaehollandiae based on morphological characteristics and phylogenetic analysis of partial sequence of the transcription elongation factor 1-alpha gene and the internal transcribed spacer of rDNA. Koch's postulates were fulfilled by successful re-isolation of the pathogen from inoculated plants in the pathogenicity assay. To our best knowledge, this is the first report of N. novaehollandiae causing root rot and foliar blight of common sage worldwide.
First Report of Rosellinia Convexa Causing Stem Rot of Olive Trees in Türkiye
(Springer, 2025) Caran, Latife Erten; Kor, Canan Vardar; Ozer, Goksel; Dervis, Sibel
Citation - WoS: 4
Citation - Scopus: 5
Ganoderma Butt Rot of Hazelnut (corylus Avellana) Caused by ganoderma Adspersum in Türkiye
(Wiley, 2024) Turkkan, Muharrem; Dervis, Sibel; Ozgumus, Oezlem; Ozer, Goeksel
In September 2022, hazelnut trees in six orchards in the & Ccedil;ar & scedil;amba district of Samsun province, a major hazelnut production area in the Black Sea region of T & uuml;rkiye, showed symptoms of leaf yellowing, shoot dieback, decline, basal stem rot and the presence of brown bracket-like sessile basidiocarps. Approximately 5%-10% of hazelnut trees were affected, highlighting the significant impact of the disease. A comprehensive morphological analysis was conducted to characterize fungal isolates obtained from symptomatic tissues as G. adspersum. This analysis incorporated features observed in basidiomata from declining trees and those reproduced after isolates were cultivated on wheat grain for spawn production and grown on an oak sawdust-based substrate. Confirmation of identification was achieved through the utilization of the internal transcribed spacer (ITS), large subunit (LSU) and small subunit (SSU) loci, along with sequencing and subsequent phylogenetic analysis. The G. adspersum isolates generally exhibited no significant growth differences at similar temperatures but demonstrated enhanced growth at 30 degrees C, while growth was completely inhibited at 40 degrees C. Incompatible reactions between isolates confirmed that distinct genotypes were present, highlighting genetic diversity within the species. In the pathogenicity trials, employing a single infested wheat grain per inoculation at the wounded site, hazelnut suckers exhibited distinct brown discolouration surrounding the inoculation site following a 2.5-month incubation period. Significantly, lesions exceeding 3 cm in length were observed, providing clear evidence of vigorous pathogenic activity by G. adspersum. This study is the first report of G. adspersum causing butt rot in hazelnuts, underscoring the significance of this finding for hazelnut cultivation and providing a foundation for future research and disease management strategies.
Citation - WoS: 3
Citation - Scopus: 8
Green Synthesis of pleurotus Eryngii-derived Nanomaterials for Phytopathogen Control
(Wiley-v C H verlag Gmbh, 2024) Acay, Hilal; Guney, Inci Guler; Yildirim, Ayfer; Dervis, Sibel; Dereli, Elif; Güler Güney, İnci
Growing concerns over the human health and environmental impacts of conventional fungicides, coupled with the escalating challenge of microbial resistance, have fueled the search for sustainable biocontrol strategies against plant pathogens. This study reports, for the first time, the green synthesis and characterization of a novel, eco-friendly nanomaterial, designated Pleurotus eryngii-Lecithin-Chitosan Nanomaterial (PEELCN), derived from P. eryngii extract (PEE), lecithin (L), and chitosan (C). The structural attributes of PEELCN were elucidated using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA), X-ray Diffraction (XRD), and zeta potential measurements, confirming the successful formation of a stable and uniform nanostructure. The antifungal activity of PEELCN, and PEE, was assessed against five economically important phytopathogenic fungi: Neoscytalidium dimidiatum, Alternaria alternata, Verticillium dahliae, Bipolaris sorokiniana, and Fusarium oxysporum. Both PEE and PEELCN exhibited significant inhibitory effects on the mycelial growth of V. dahliae, B. sorokiniana, and N. dimidiatum, with varying degrees of efficacy. The differential antifungal activity suggests a species-specific mode of action. The findings highlight the promising potential of PEELCN as a sustainable, biocompatible, and cost-effective nanofungicide for the management of plant diseases, with the potential for development into a commercially viable biofungicide for sustainable agriculture.
Citation - WoS: 6
HOST SELECTIVE VIRULENCE, TEMPERATURE RESPONSE AND GENETIC DIVERSITY IN MACROPHOMINA PHASEOLINA ISOLATES FROM SESAME AND PEANUT IN SOUTHERN TURKEY
(PARLAR SCIENTIFIC PUBLICATIONS (P S P), 2018) Tok, Fatih Mehmet; Dervis, Sibel; Arslan, Mehmet
In this work, host specificity (comparing virulence levels on diverse hosts), temperature response as a physico-morphological characteristic, and genetic diversity of 40 M. phaseolina isolates from sesame and peanut plants with different geographic origins were evaluated. Sesame and peanut isolates of M. phaseolina performed different levels of virulence on maize, watermelon, melon, peanut, and soybean. The temperatures between 25 and 30 degrees C were the optimum temperatures for colony size of isolates from sesame and peanut. A temperature of 25 degrees C was optimal for only 26 isolates (65%), but 30 degrees C was optimal for 39 isolates (97.5%). UPGMA clustering of data indicated that the Sesame and peanut isolates displayed various levels of genetic similarity within a range of 0.79 to 1.0 similarity coefficient index in three major cluster groups. With a few exceptions, isolates from the same or close locations tended to group together.
Lasiodiplodia Theobromae and Neoscytalidium Dimidiatum Associated with Grafted Walnut (Juglans Regia L.) Decline in Turkey
(Springer Heidelberg, 2023) Ozer, Goksel; Turkolmez, Sahimerdan; Dervis, Sibel; Ciftci, Osman
Surveys of canker diseases in 26 walnut orchards were conducted in the southeastern Turkish provinces of Batman, Diyarbakir, and Sanliurfa in 2020. Decline symptoms on trees were most severe in the trunks of grafted trees grown on unproductive local rootstocks with Chandler and Franquette scions throughout the surveyed areas, and samples were taken from those trees. Lasiodiplodia theobromae was identified from the cankers on the trees of the seven orchards, while Neoscytalidium dimidiatum was identified from the other 19 orchards based on morphological characteristics. DNA sequencing analysis of 10 representative isolates using the ITS1-5.8S-ITS2 (ITS), the large subunit (LSU), and the translation elongation factor 1-alpha (EF-1 alpha) genes confirmed the identification of the causal fungi. Pathogenicity tests on 2 year-old Chandler seedlings revealed that L. theobromae and N. dimidiatum produced lesion length averages of 7-8 cm and 15-25 cm after 3 weeks of stem-inoculation, respectively. Koch's postulates were confirmed by successfully reisolating the fungi only from plants inoculated. This is the first study to document L. theobromae as the causal agent of walnut tree decline and cankers in Turkey.