Browsing by Author "Polat, Zuhtu"

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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 - Scopus: 1
Pathogen Identification And Resistance Screening Of Fusarium Basal Rot İn Taşköprü Garlic İn Türkiye
(Wiley, 2024) Polat, Zuhtu; 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.
Tissue Type and Cultivar-by-Isolate Interactions Govern Walnut (Juglans Regia) Resistance to Diaporthe Eres in Türkiye
(Academic Press Ltd- Elsevier Science Ltd, 2026) Orman, Erdal; Ozer, Goksel; Polat, Zuhtu; Dervis, Sibel; Turkkan, Muharrem; Gultekin, Mehmet Akif
Diaporthe eres is increasingly reported as a causal agent of canker, shoot dieback, and fruit rot of walnut (Juglans regia L.) in diverse production regions. In this study, multi-locus phylogenetic analysis using ITS, tef1, and tub2 gene sequences confirmed that two isolates, ED 5/4 (Edirne) and BUR 7/4 (Bursa), belong to D. eres sensu stricto, showing 99-100% sequence identity with ex-type strain AR5193 in BLASTn analysis and clustering with high bootstrap support in Maximum Likelihood phylogenetic trees. Pathogenicity assays conducted on green fruits, current-season shoots, and one-year-old dormant branches of seven cultivars revealed strong and statistically significant cultivar & times; isolate interactions, demonstrating that resistance responses were highly isolate-specific. Isolate BUR 7/4 displayed higher virulence overall than ED 5/4. Lesion development differed markedly among tissue types, with current-season shoots consistently exhibiting substantially greater necrosis than oneyear-old dormant branches, indicating a pronounced influence of tissue ontogeny on host susceptibility. Cultivar performance varied among tissues: 'Chandler' showed the greatest resistance in woody tissues, whereas 'Fernor' and 'Orman 77 ' were consistently susceptible. Fruit assays demonstrated variable husk susceptibility but uniformly severe, cultivar-independent kernel decay, indicating the absence of internal resistance once the husk barrier was breached. D. eres was re-isolated from all symptomatic tissues while controls remained healthy, fulfilling Koch's postulates. These results establish D. eres as an important contributor to walnut canker and fruit rot in Türkiye and emphasize the roles of tissue-specific susceptibility, isolate diversity, and cultivar-dependent responses in shaping disease outcomes and informing resistance-based management strategies.