Bitkisel ve Hayvansal Üretim Bölümü Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12514/201

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Characterization and pathogenicity of Pythium-like species associated with root and collar rot of kiwifruit in Turkey
(In Plant Disease, 2021) Türkkan, Muharrem; Özer, Göksel; Karaca, Gürsel; Erper, İsmail; Derviş, Sibel
During the period of June to October in 2018, a widespread decline was observed on kiwifruit vines in the vineyards located in Altınordu, Fatsa, and Perşembe districts of Ordu province. The symptoms were associated with reddish-brown rots expanding from the root to the collar with sparse off-color foliage. Based on the percentage of the total infected samples across 18 vineyards, the most common oomycete species were Globisporangium intermedium (37.1%), Phytopythium vexans (34.3%), G. sylvaticum (14.3%), G. heterothallicum (11.4%), and Pythium dissotocum (2.9%). The morphological identification of isolates was confirmed based on partial DNA sequences containing the nuclear rDNA internal transcribed spacer region (rDNA ITS) and the mitochondrial cytochrome c oxidase subunit II (coxII) gene. The optimum growth temperature and the optimum pH of 5 species ranged from 22.98 to 28.25°C and 5.67 to 8.51, respectively. Pathogenicity tests on the seedlings of kiwifruit cv. Hayward revealed significant differences in virulence among isolates. Phytopythium vexans and G. sylvaticum isolates caused severe root and collar rot resulting in seedling death, while G. heterothallicum and G. intermedium isolates had relatively lower virulence. All Globisporangium spp. and P. vexans isolates significantly decreased plant growth parameters (plant height, shoot and root dry weights and root length); however, P. dissotocum caused very mild symptoms and did not affect these parameters of growth. To our knowledge, this is the first study reporting G. sylvaticum, G. heterothallicum, and G. intermedium causing root and collar rot on kiwifruit not only in Turkey but also in the world.
First report of binucleate Rhizoctonia AG-F causing stalk and root rot of corn (Zea mays) in Turkey
(2019) Türkölmez, Şahimerdan; Çiftçi, Osman; Derviş, Sibel; Ulubaş Serçe, Çiğdem
Maize or sweet corn (Zea mays L.) is one of the most widely grown and important cereal crops in terms of its area coverage and contribution to total food grains production in the world. In Turkey, approximately 640,000 ha Q:2 of land is under maize cultivation producing 5.9 million metric tons of grain. In Turkey, S¸ anlıurfa is the third largest province for corn cultivation after Adana and Mardin. In the summer of 2018, plants with suppressed growth owing to a root and stalk rot were observed in a corn field (37°27957.80N, 39°26928.90E) with an area of 8 ha located in Karakeçi neighborhood of Siverek (northern S¸ anlıurfa). Approximately 8.8% of the plants were affected. Observed symptoms started with chlorosis of the leaves followed by brown to dark-brown discoloration or rapid death of the upper leaves or whole plant. When the stalk and crown tissues were split longitudinally, we observed a brown to black dry rot or necrosis throughout the central pith and internal tissues of the stalk and crown, which resulted in a hollow stem. Affected plants showed varying degrees of necrosis on roots and crowns, and rotted roots. Plants with stalk rot easily lodged, or bent in severe cases. Isolations were performed from the margin of symptomatic stalk piths, crowns, and secondary and tap roots on potato dextrose agar (PDA) amended with streptomycin sulfate (100 ppm). Fungal colonies recovered were yellowish-gray with a powdery texture. The fungal isolates were preliminarily identified as Rhizoctonia sp. on the basis of colony morphology and typical hyphal branching pattern (i.e., hyphal ramification angles of ;90°, basal constriction, and a septum next to the lateral hyphae) (Sneh et al. 1991). Nuclear staining with a 1% Safranin O and 3% KOH (Bandoni 1979) and examination under light microscopy at ×400 magnification confirmed that hyphal cells of all isolates had two nuclei per cell (binucleate), belonging to the teleomorphic genus Ceratobasidium. No sclerotia were formed after 20 days on PDA. The genomic DNA of two isolates was extracted, and the partial internal transcribed spacer (ITS) 1, complete 5.8S ribosomal RNA gene, and partial ITS2 region of the nuclear rDNA was amplified by using the primers ITS6/ITS4. The nucleotide sequences obtained (GenBank accession nos. MK442087 and MK442088) had 100 and 99% identity, respectively, with many sequences of binucleate Rhizoctonia AG-F subgroup in NCBI database, including KT265714 and KT265715 isolated from ginger and taro in China (Dong et al. 2017), thus confirming the morphological identification. Pathogenicity tests were performed on 3-week-old healthy potted seedlings of Z. mays ‘Pioneer 2105’. Twenty plants were inoculated by placing three 1-cm-diameter mycelial plugs from 5-day-old PDA cultures of a representative isolate near the crown of plants. Fifteen plants inoculated with only PDA plugs served as controls. The plants were maintained in a growth chamber at 25 ± 1°C and 95% relative humidity with a 16-h/8-h (light/dark) photoperiod. All inoculated plants showed extensive necrosis on the roots and crown, resulting in growth reduction. The symptoms observed 15 days after inoculation were similar to those found in the commercial field. Control plants remained healthy. Binucleate Rhizoctonia was reisolated from symptomatic tissues of inoculated plants, completing Koch’s postulates. To our knowledge, this is the first report of binucleate Rhizoctonia AG-F causing stalk, crown, and root rot on Z. mays in the world. The finding of this pathogen on corn in Turkey needs to be considered when designing disease management programs for corn production.
First report of Neoscytalidium dimidiatum causing black canker and root rot of walnut in Turkey
(2019) Derviş, Sibel; Türkölmez, Şahimerdan; Çiftçi, Osman; Ulubaş Serçe, Çiğdem; Dikilitaş, Murat
Walnut (Juglans regia L.) is commercially important with about 87,670 ha grown in Turkey, the fourth largest producer worldwide. During summer 2018, unfamiliar and serious decline symptoms associated with stem and branch cankers were observed in walnut trees in two orchards in S¸ anlıurfa Province, Southeastern Anatolia Region. In a 3-year-old orchard of 450 trees (cv. Chandler) in Kayseri, Siverek District, about 62% of trees had deep, large, and black cankers in the trunks and on main branches, drastically reduced tree vigor, and yellowing, wilting, and browning of the leaves, followed by leaf drop. In a 12-year-old orchard with 30 trees (cv. Kaman), in Yaylak, Bozova District, 40% of trees had similar symptoms. Symptoms were first noticed in trunks. Bark cracks, cankers in trunks, and dark discoloration or a black sooty, dusty mass of fungal spores under peeling bark on the trunk and main branches were the most striking symptoms. Deep cankers expanded longitudinally, extending along trunks and into the phloem of the trees, which consequently died, and occasionally laterally extending into the sapwood. Declining trees had dry root rot symptoms, with black necrosis on the surface, and under the cracked and coarse bark extending from the taproot and some large roots to the crown, and black rot and loss of fine roots. Samples were taken from under the bark of trunk cankers, crown tissues, and root tissues of five trees per Q:1 orchard. The sections of samples were surface sterilized in 2% NaOCl for 2 min and rinsed twice in sterile distilled water, blotted dry with sterilized filter paper, placed on PDA, and incubated at 28°C. A fungus with identical cultural characteristics was consistently isolated. On PDA, the mycelium growth was white and then turned black with age. Rapidly growing colonies (average, 40 mm/day) produced mycelia that disarticulated into 0- to 1-septate, cylindrical-truncate or rod-shaped, thick-walled, hyaline to brown arthroconidia occurring singly or in arthric chains and averaged 9.6 ± 3.7 × 5.5 ± 1.6 μm with a length/width ratio of 1.79. These characteristics were consistent with the description of the arthric synanamorph of Q:3 Neoscytalidium dimidiatum (Penz.) Crous & Slippers (Crous et al. 2006). The rDNA internal transcribed spacer (ITS) and large subunit (LSU) genes of two single conidial isolates (one from under bark tissues; one from root tissues) were amplified with ITS6/ITS4 and NL1/NL4 primer pairs, respectively, and the amplicons sequenced. The ITS and LSU sequences deposited in GenBank (ITS, MK430050 and MK430051; LSU, MK430056 and MK430057) had 100% identity with many sequences of N. dimidiatum, including recently available ones (T¨urk¨olmez et al. 2019; ITS, MH114591; LSU, MH114592), in line with the morphological features. Pathogenicity tests were performed on 20 replicates of 1-year-old container-grown J. regia ‘Chandler’ seedlings with a N. dimidiatum isolate by removing a 5-mm-diameter bark plug from the stem with a cork borer and placing an equivalent-sized 7-day-old culture disc of N. dimidiatum onto the exposed vascular cambium. The wound was covered with wet, autoclaved cotton wool and sealed with Parafilm. Treated plants were maintained in a growth chamber with a 16/8-h light/dark photoperiod at 26°C and 55% RH and watered on demand. Within 3 weeks, average lesion lengths under the bark of all inoculated stems were >150 mm, and the lesions were covered with a black sooty layer. Leaf blight was also observed, similar to naturally affected trees. Control plants remained healthy. N. dimidiatum was reisolated only from lesions of inoculated stems, fulfilling Koch’s postulates. In Turkey, N. dimidiatum has been reported as a destructive new blight of tomato (T¨urk¨olmez et al. 2019) and canker, shoot blight, and root rot of pistachio (Dervis¸ et al. 2019). This is the first report of N. dimidiatum infection of walnuts in Turkey. By the end of 2018, all symptomatic trees had died. Recent occurrence of this severe disease suggests it could have a significant potential for limiting walnut production.
New disease caused by Neoscytalidium dimidiatum devastates tomatoes (Solarium lycopersicum) in Turkey
(ELSEVIER SCI LTD, 2019) Turkolmez, Sahimerdan; Dervis, Sibel; Ciftci, Osman; Serce, Cigdem Ulubas; Dikilitas, Murat
A novel disease of tomato (Solarium lycopersicum L.) was observed in the Southeast Anatolia Region of Turkey. Symptoms were blight of all aerial parts of the plant, including stems, branches, leaves, petioles, flowers and fruits, defoliation, root rot, inner stem necrosis, and plant death. The disease was found in 13.9% of surveyed fields, with an incidence varying from 3% to nearly 75% (average 21.2%) of the plants in symptomatic fields. The average severity of blight on stem in fields with the symptomatic plant surveyed was 1.4%. A Botryosphaeriaceae species, identified as Neoscytalidium dimidiatum (Penz.) Crous & Slippers using morphological and cultural features, was consistently isolated from symptomatic roots, inner stems, and blighted leaves, shoots, stems, fruits and flowers. The partial nucleotide sequence data for three gene loci, including nuclear rDNA internal transcribed spacer (ITS), large subunit (LSU) genes and the translation elongation factor 1-alpha (TEF-1 alpha), confirmed the morphological identification. Furthermore, sequence data of actin genes from N. dimidiatwn was, for the first time, deposited to the GenBank. Koch's postulates were fulfilled by testing the susceptibility of different tomato tissues (leaves, stems, inner stems and roots of tomato seedlings, and detached tomato fruits and flowers) to N. dimidiatum inoculation. To our knowledge, this is the first report of N. dimidiatum on tomato.
A Whole Genome DArTseq and SNP Analysis for Genetic Diversity Assessment in Durum Wheat from Central Fertile Crescent
(Plos one, 2017) Baloch, Faheem Shehzad; Alsaleh, Ahmad; Shahid, Muhammad Qasim; Çiftçi, Vahdettin; Miera, Luis E. SaÂenz de; Aasim, Muhammad; Nadeem-, Muhammad Azhar; Aktaş , Hüsnü; Özkan, Hakan; Hatipoğlu, Rüştü
A Whole Genome DArTseq and SNP Analysis for Genetic Diversity Assessment in Durum Wheat from Central Fertile Crescent

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