Browsing by Author "Ozer, Goksel"

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Armillaria Species Causing Kiwifruit Vine Decline and Root Rot in Northeastern Türkiye: a Growing Concern for Kiwifruit Health
(Wiley, 2024) Derviş, Sibel; 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) Derviş, Sibel; Bozoglu, Tugba; Dervis, Sibel; Erper, Ismail; Ozer, Goksel
First Report Of Colletotrichum Perseae Causing Anthracnose Disease of Avocado ( Persea Americana) in Türkiye
(Academic Press Ltd- Elsevier Science Ltd, 2024) Derviş, Sibel; 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.
First report of Neoscytalidium novaehollandiae on common sage (Salvia officinalis)
(Springer link, 2021) Derviş, 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.
Leaf Spot Caused by Alternaria Crassa on Datura Stramonium in Turkey (Vol 17, 26, 2022)
(Springer, 2022) Derviş, Sibel; Alkan, Mehtap; Dervis, Sibel; Ozer, Goksel
Morphological, physiological, molecular, and pathogenic insights into the characterization of Phytophthora polonica from a novel host, hazelnut (Corylus avellana)
(Academic Press Ltd- Elsevier Science Ltd, 2024) Derviş, Sibel; Ozer, Goksel; Dervis, Sibel
Hazelnuts, constituting a significant global crop, hold paramount importance in Turkiye, contributing to approximately 71.14 % of the world's hazelnut cultivation area. In the summer of 2023, hazelnut trees in two orchards situated in the Altinordu district of Ordu province, within the Black Sea region of Turkiye, the largest producer and exporter of hazelnuts, exhibited symptoms of decline associated with root rot. Phytophthora sp. was consistently isolated from necrotic taproots, initiating an in-depth study to discern the causal agent behind the observed hazelnut decline. The species was identified as P. polonica by its distinctive morphological traits, including homothallic characteristics, amphigynous or paragynous antheridia, long nonbranching sporangiophores, and nonpapillate sporangia with internal proliferation. Multiple genetic markers (ITS, tub2, and COI) facilitated a clear differentiation of P. polonica from other Phytophthora species within Clade 9, supporting its classification within Subclade 9b. This investigation also evaluated the impact of diverse nutrient media (CA, V8A, and CMA), temperatures, and pH levels on the mycelial growth of P. polonica HPp-1 and HPp-2 isolates. The optimal conditions for maximal mycelial growth were determined through the D-optimal design of the Response Surface Method, revealing the significant influence of all factors on mycelial growth. The identified optimal conditions were at 26.09 degrees C, pH 5.12, with CMA as the nutrient medium. Validation experiments conducted under these optimal conditions unveiled mycelial growth of 7.24 +/- 0.15 mm day(-1) and 6.81 +/- 0.09 mm day(-1) for P. polonica HPp-1 and HPp-2 isolates, respectively, with an error of less than 5 %. Pathogenicity assessments confirmed P. polonica's virulence on hazelnuts, with distinct lesion development observed in twig inoculation, cut stem segments, and foliar tests. While no statistically significant difference was noted in lesion areas between HPp-1 and HPp-2 isolates in twig and stem segment assays, a statistical difference in leaf lesion areas (19.96 +/- 2.04 cm(2) and 9.16 +/- 3.43 cm(2)) emerged in foliar tests after only a 5-day incubation period, indicating their high susceptibility to the pathogen. This study is the first to report P. polonica as a hazelnut pathogen in Turkiye and around the world, highlighting the previously non-existent threat of Phytophthora root rot in hazelnuts, given the substantial lack of scientifically documented cases related to hazelnut root rot diseases. The quadratic model design employed in physiological analyses is reliable for optimizing mycelial growth and can serve as a guiding framework for similar investigations.
Neoscytalidium dimidiatum: A newly identified postharvest pathogen of pears and its implications for pome fruits
(Wiley, 2024) Derviş, Sibel; Zholdoshbekova, Sezim; Guney, Inci Guler; Ozer, Goksel
T & uuml;rkiye is a prominent contributor to pear and diverse pome fruit production. Pear fruit with unusual brown to black spots and rot symptoms observed in public marketplaces in Mardin province have raised concerns regarding postharvest fruit health. The consistent isolation of a fungus from these fruits revealed morphological features indicative of Neoscytalidium dimidiatum. Phylogenetic confirmation of its identity ensued through BLASTn searches targeting, the internal transcribed spacer (ITS) of ribosomal DNA, the partial translation elongation factor 1-alpha gene (tef1), and the partial beta-tubulin gene (tub2). Pathogenicity evaluations were conducted on common pome fruits, namely pears, apples, and quinces, unveiling the susceptibility of all examined fruits to postharvest infection by this emergent pathogen. Furthermore, an investigation was carried out to discern the pathogen's response to varying temperature ranges on pear fruits, revealing that the most pronounced lesions occurred at 30 degrees C, followed by 25 degrees C, 35 degrees C, and 20 degrees C. Conversely, no lesion development was observed at 10 degrees C, 15 degrees C, or 40 degrees C. To the best of our knowledge, this study represents the first report of N. dimidiatum as the etiological agent responsible for postharvest rot in pear fruit. The implications of these findings highlight the potential threat posed by this pathogen to pome fruits postharvest, especially in regions where cold storage facilities are not widely utilized, warranting increased vigilance and preventive measures.
New Detection Methods for Cryphonectria Hypovirus 1 (chv1) Through Sybr Green-Based Real-Time Pcr and Loop-Mediated Isothermal Amplification (lamp)
(Mdpi, 2024) Derviş, Sibel; Cakar, Deniz; Dervis, Sibel; Morca, Ali Ferhan; Simsek, Secil Akilli; Romon-Ochoa, Pedro; Ozer, Goksel
Some mycoviruses can be considered as effective biocontrol agents, mitigating the impact of phytopathogenic fungi and consequently reducing disease outbreaks while promoting plant health. Cryphonectria parasitica, the causal agent of chestnut blight and a highly destructive pathogen, experienced a notable decrease in its virulence with the identification of cryphonectria hypovirus 1 (CHV1), a naturally occurring biocontrol agent. In this study, two innovative diagnostic protocols designed for the accurate and efficient detection of CHV1 are introduced. The ORF A and ORF B regions of CHV1 are targeted by these techniques, which employ colorimetric loop-mediated isothermal amplification (LAMP) with 2 Colorimetric LAMP Master Mix and real-time quantitative PCR (qPCR) with SYBR Green chemistry, respectively. The LAMP assay presents a discernible color transition, changing from pink to yellow after a 35 min incubation period. Comparative analysis, when assessed against two established reverse transcription-PCR (RT-PCR) techniques, reveals a significant enhancement in sensitivity for both the LAMP approach, which offers a tenfold increase, and the qPCR method, which showcases a remarkable 100-fold sensitivity improvement. Throughout the comparison phase, it was evident that the RT-PCR, LAMP, and qPCR procedures displayed superior performance compared to the Bavendamm test, relying on phenol oxidase activity, effectively distinguishing hypovirulent strains. Consequently, this study introduces two pioneer diagnostic assays for highly sensitive CHV1 detection, representing a substantial advancement in the realm of CHV1 surveillance techniques. These methodologies hold significant promise for enhancing research endeavors in the domain of the biological control of C. parasitica.
Pathogen Identification And Resistance Screening Of Fusarium Basal Rot İn Taşköprü Garlic İn Türkiye
(Wiley, 2024) Derviş, Sibel; Besirli, Gulay; Dervis, Sibel; Ozer, Goksel; Sezer, Sati Mehmet; Ipek, Mehmet
Fusarium basal rot (FBR), caused by Fusarium spp., is a significant threat to garlic production globally, including in T & uuml;rkiye, where the unique Ta & scedil;k & ouml;pr & uuml; garlic is highly valued. This study investigated the diversity and aggressiveness of 77 Fusarium isolates obtained from disease surveys of FBR in Ta & scedil;k & ouml;pr & uuml; garlic and evaluated the yield and resistance of 20 garlic accessions, including 18 local landraces, the locally developed 'Ta & scedil;k & ouml;pr & uuml; 56', and the commercial Chinese variety 'ASCG'. Molecular identification using translation elongation factor 1-alpha (TEF1) and second largest RNA polymerase II B-subunit (RPB2) genes revealed F. oxysporum (67.5%) as the dominant species, followed by F. proliferatum (15.6%), F. solani (9.1%), F. redolens (5.2%) and F. clavum (2.6%), respectively. All isolates were pathogenic, but aggressiveness varied, with F. solani being the most aggressive, followed by F. redolens and F. oxysporum. While 'ASCG' exhibited the highest yield (3.15 ton/ha), it was highly susceptible to FBR (DSI = 97.50%). Conversely, the landrace ASTK2 displayed the highest resistance (DSI = 53.13%), but lower yield. Promisingly, several Ta & scedil;k & ouml;pr & uuml; landraces, such as ASTK6 and ASTK13, demonstrated both moderate resistance and promising yield potential. Surprisingly, 'Ta & scedil;k & ouml;pr & uuml; 56', despite being a locally developed variety, exhibited high susceptibility to FBR (DSI = 93.75%) and did not outperform many landraces in terms of yield. This study provides the first reports of F. redolens and F. clavum infecting garlic in T & uuml;rkiye, and the first molecular characterisation of F. solani as a garlic pathogen in the country, highlighting the potential of local landraces for breeding FBR-resistant, high-yielding cultivars.