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Öğe Detection of Bean Common Mosaic Virus in Bean Seeds by Immunocapture RT-PCR and DAS-ELISA Methods(2022) Kılıç, Handan Çulal; Cat, AhmetThis study was carried out in bean seeds in Isparta and Antalya provinces to determine Bean common mosaic virus (BCMV) in 2016. For this purpose, 106 seed samples were collected from the research area. Seed samples were used for biological, serological, and molecular methods. The virus incidence, as a percentage of seeds samples for BCMV, was found 87.73% by DAS-ELISA and 90.56% by Immunocapture Reverse Transcriptase-Polymerase Chain Reaction (IC-RT-PCR) methods. As a result of the study, BCMV was detected in a total of 96 (90.56%) seed samples. 93 samples were detected positive with the DAS-ELISA method, while 96 samples were found to be infected with BCMV using the IC-RT-PCR method. In the IC-RT-PCR method, approximately 850 bp of the coat protein gene was amplified with specific primers and BCMV specific bands were obtained at the expected levels.Öğe Evaluating Scald Reactions of Some Turkish Barley (Hordeum vulgare L.) Varieties Using GGE Biplot Analysis(Mdpi, 2023) Akan, Kadir; Cat, Ahmet; Hocaoglu, Onur; Tekin, MehmetScald caused by the fungal pathogen Rhynchosporium commune is a significant foliar disease affecting barley production on a global scale, and it leads to substantial reductions in both yield and quality of barley. In the current study, the reactions of 40 Turkish barley (Hordeum vulgare L.) varieties to scald were evaluated under natural conditions in canakkale and Kirsehir in 2021-2022, and Antalya and Siirt locations in 2022-2023 growing seasons. Field trials were conducted according to randomized block design with three replications in each year; the spore concentration was 1 x 10(6) spores per mL, and it was applied to the varieties three times at different growth stages. The reactions of barley varieties were assessed using a newly designed two-digit scale ranging from 11 to 99. Based on their scale values, the varieties were categorized as immune (0), resistant (11-35), moderately resistant (36-55), moderately susceptible (56-75), and susceptible (76-99). In addition, genotype plus genotype-by-environment (GGE) interactions of scale values were analyzed through GGE Biplot and explained 97.65% of the total variation. The ranking of genotypes based on scale groups generally showed consistency with GGE Biplot results, but GGE Biplot offered a more detailed classification, especially for moderately susceptible varieties. The relationship between the two methods indicated the relative stability of variety reactions, as GGE Biplot analysis also considered genotype stability. In conclusion, the use of the newly developed scale for evaluating scald reactions in barley gives reliable results. In addition, identified resistant varieties can serve as valuable genetic resources for further breeding studies.Öğe Evaluation of genetic variation and host resistance to wheat stem rust pathogen ( Puccinia graminis f. sp. tritici ) in bread wheat ( Triticum aestivum L.) varieties grown in Türkiye(Peerj Inc, 2024) Cat, AhmetWheat stem rust, which is caused by Puccinia graminis f. sp. tritici ( Pgt ), is a highly destructive disease that affects wheat crops on a global scale. In this study, the reactions of 150 bread wheat varieties were evaluated for natural Pgt infection at the adult -plant stage in the 2019 - 2020 and 2020 - 2021 growing seasons, and they were analyzed using speci fi c molecular markers to detect stem rust resistance genes ( Sr22 , Sr24 , Sr25 , Sr26 , Sr31 , Sr38 , Sr50 , and Sr57 ). Based on phenotypic data, the majority of the varieties (62%) were resistant or moderately resistant to natural Pgt infection. According to molecular results, it was identi fi ed that Sr57 was present in 103 varieties, Sr50 in nine varieties, Sr25 in six varieties, and Sr22 , Sr31 , and Sr38 in one variety each. Additionally, their combinations Sr25 + Sr50 , Sr31 + Sr57 , Sr38 + Sr50 , and Sr38 + Sr57 were detected in these varieties. On the other hand, Sr24 and Sr26 were not identi fi ed. In addition, many varieties had low stem rust scores, including a large minority that lacked Sr57 . These varieties must have useful resistance to stem rust and could be the basis for selecting greater, possibly durable resistance.Öğe Evaluation of resistance of Turkish bread wheat (Triticum aestivum) varieties to recently emerged Puccinia striiformis f. sp. tritici races(Academic Press Ltd- Elsevier Science Ltd, 2022) Tekin, Mehmet; Cat, Ahmet; Akan, Kadir; Demir, Hanife; Akar, TanerUsing genetic diversity has made significant contribution to stripe rust resistance to improve wheat production. However, rapid evolution of the Puccinia striiformis f. sp. tritici (Pst), and emergence of virulent races can negatively affect the wheat genotypes with race-specific resistance gene(s). In this study, reactions of 130 bread wheat varieties, released from 1931 to 2014, were evaluated to recently emerged Pst races in Turkey, PSTr-6 and PSTr-23, at seedling and adult-plant stages. 65.4% and 67.7% of wheat varieties showed susceptible reaction to PSTr-6 and PSTr-23 at seedling stage, respectively. Moreover, coefficient of infection (CI) values generated by infection type (IT) and disease severity (DS) data demonstrated that PSTr-23 (59.78) was more virulent than PSTr-6 (57.93) at adult-plant stage. In addition to these, the presence of important yellow rust (Yr) genes in these varieties was investigated at molecular level. It was determined that the frequencies of three Yr genes, Yr5, Yr10 and Yr15, among these varieties were 1.5, 6.2 and 3.8%, respectively. However, none of them had Yr36 and only one variety had Yr5+Yr10 combination with frequency of 0.7%. In conclusion, most varieties have not these Yr genes and possess a moderately resistance/susceptible reaction to both races in general.Öğe Genetic Diversity and Population Structure of Wheat Stripe Rust Pathogen (Puccinia striiformis f. sp. tritici) in Turkey(Amer Phytopathological Soc, 2024) Cat, Ahmet; Tekin, MehmetStripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most important diseases threatening wheat production both in Turkey and worldwide. However, the underlying genetic dynamics of Pst populations are not fully known in Turkey. To determine the population genetic structure and migration network among regional Pst populations, a total of 140 Pst isolates collected from six geographical regions of Turkey from 2018 to 2020 were sampled and genotyped using 21 simple sequence repeat loci. A total of 70 multilocus genotypes were identified and classified into the three major genetic groups by Bayesian assignment. The highest genotypic diversity was detected in Southeastern Anatolia, showing its critical role as one of the source populations to trigger possible stripe rust epidemics. Analysis of molecular variance revealed the highest variation (90.25%) within isolates. The migration network generated by the number of effective migrants showed that the highest migration (1.0) was determined between Southeastern Anatolia and Central Anatolia, and considerable levels of migration (>0.2) were determined among the other regions, except for the Black Sea. Linkage equilibrium (P >= 0.05) was detected for many geographical regions, except for Marmara (P = 0.00) and the Mediterranean (P = 0.03), suggesting that reproduction of Pst populations is most likely sexual or mixed (sexual and clonal). To sum up, this is the first study on the genetic relationships and population genetic structure of the Pst population in Turkey, and these findings may provide critical information to develop management strategies for wheat stripe rust.Öğe Molecular characterizations of Verticillium dahliae isolates from grafted tomatoes grown in Antalya province of Türkiye(Wiley, 2024) Akar, Hasan; Cat, Ahmet; Catal, MurselVerticillium wilt caused by soil-borne fungus Verticillium dahliae results in serious quality, yield and economic losses in tomato fruit production in tomato-growing areas around the world. In this study, V. dahliae isolates obtained from six different major grafted tomato production areas in Antalya province of Turkiye were characterized for races, pathotypes and vegetative compatibility groups using the specific PCR primers. Out of 66 isolates, 60 were determined to be race 2. Six isolates were not identified as race 1 or race 2. Fifty-six isolates were determined as defoliating pathotypes (D) while 10 isolates were identified as non-defoliating (ND) pathotypes. The isolates were clustered into four vegetative compatibility groups (VCGs): VCG1A (61), VCG2A or VCG4B (3), VCG2B (1) and VCG6 (1). According to the results of this study, the race 2, D pathotype and VCG1A isolates were dominant and widely distributed in the region. Additionally, the V. dahliae isolates fall into two major groups based on the dendrogram constructed from molecular data by Dice similarity index. The dendrogram showed significant diversity among the V. dahliae isolates particularly in the Elmali region compared to other regions. The study is the first comprehensive research with the current disease and race 2 was identified for the first time in grafted tomatoes. These findings will lead to the development of V. dahliae-resistant grafted tomatoes and breeding programs in Turkiye.Öğe Phenotypic and genotypic evaluation of Turkish bread wheat (Triticum aestivum L.) varieties to stripe rust (Puccinia striiformis f.sp. tritici)(Wiley, 2024) Cat, AhmetWheat stripe rust, which is caused by the basidiomycetes fungal pathogen Puccinia striiformis f.sp. tritici (Pst), is one of the most destructive diseases of wheat in Turkiye and worldwide. In this study, a total of 99 bread wheat varieties were assessed at the adult plant stage under natural infection conditions during the 2021-2022 and 2022-2023 growing seasons. Additionally, specific molecular markers were used to genotype the stripe rust resistance genes Yr26, Yr32, Yr36, Yr44 and YrSP. Disease severity was determined using the modified Cobb scale and infection reactions of each bread wheat varieties were evaluated, and also coefficient of infection value was calculated based on those parameters. To determine whether the wheat varieties had resistance gene(s), specific molecular markers associated with the resistance genes Yr26, Yr32, Yr36, Yr44 and YrSP were used. In the field trials, the majority of the tested varieties showed moderately susceptible and susceptible reactions in both years. According to the molecular results, they were positive for Yr32 in three varieties, Yr36 in 25 varieties, YrSP in two varieties and none of them had Yr26. Furthermore, some varieties carried combinations of these genes, such as Yr32 + Yr36, Yr32 + Yr44, Yr36 + Yr44, Yr36 + YrSP, Yr32 + Yr36 + Yr44 and Yr32 + Yr36 + Yr44 + YrSP. On the other hand, it was not determined these resistance genes in 16 varieties. In the literature, these resistance genes were first identified in Turkish bread wheat varieties. In addition, these findings are valuable for the development of wheat cultivars with effective and more durable resistance to stripe rust in Turkiye.Öğe Races of Puccinia striiformis f. sp. tritici identified from the coastal areas of Turkey(Taylor & Francis Inc, 2021) Cat, Ahmet; Tekin, Mehmet; Akan, Kadir; Akar, Taner; Catal, MurselStripe rust, caused by Puccinia striiformis f. sp. tritici, is a devastating disease of wheat in Turkey and worldwide. This pathogen can overcome known resistance genes and negatively affect the wheat production. The objectives of this study were to determine the virulence patterns of wheat stripe rust isolates collected from the coastal areas (Aegean and Mediterranean regions) of Turkey, and to examine the genetic diversity of the pathogen populations by simple sequence repeat (SSR) marker analysis. The majority of the isolates collected were virulent at various frequencies on the resistance genes Yr1 (50%), Yr6 (100%), Yr7 (78%), Yr8 (50%), Yr9 (84%), Yr10 (25%), Yr17 (38%), Yr24 (22%), Yr27 (31%), Yr32 (22%), Yr43 (47%), Yr44 (6%), YrSp (41%), YrTr1 (6%), and avirulent on Yr5 and Yr15. Based on the analysis of virulence, all isolates were determined as 25 races and clustered into six virulence groups (VGs). In contrast, the isolates clustered into four molecular groups (MGs) based on genotypic data. All four MGs were found in Aegean region of Turkey, while only three MGs (MG1, MG2 and MG3) were found in the Mediterranean region of the country. Additionally, analysis of molecular variance indicated that 80.9% of genetic variation was found within regions and 19.1% was found between the regions. The results suggest that interregional migration of the pathogen was high. The data can be helpful for the management of stripe rust and understanding the population structure and migration of Pst in Turkey.Öğe Resistance to stripe rust in Turkish durum wheat varieties and wild emmer genotypes(Springer Heidelberg, 2023) Ipek, Emre; Tekin, Mehmet; Cat, Ahmet; Akar, TanerStripe or yellow rust caused by Puccinia striiformis f. sp. tritici (Pst) is the most important disease of wheat causing significant yield losses. Growing resistant varieties is the most efficient and sustainable way to control this disease. The aim of this study was to investigate molecularly the presence or absence of the major resistance genes Yr5, Yr10 and Yr15 to stripe rust in 54 Turkish durum wheat (Triticum turgidum var. durum) varieties and 11 wild emmer (Triticum turgidum var. dicoccoides) genotypes. In addition, field trials were conducted during 2019-2020 under natural epidemic conditions in Antalya to determine phenotypic reactions of these genotypes against stripe rust. As a result of molecular analyses, none of the 54 durum wheat varieties had Yr5 resistance gene; however, the resistance genes Yr10 and Yr15 were determined in 12 and 17 varieties, respectively. Moreover, 7 of these varieties had both Yr10 and Yr15 genes. None of 11 wild emmer accessions had resistance genes examined. It was also determined that 28 varieties had resistant reaction to Pst race(s) under natural infection conditions whereas all wild emmer accessions were highly susceptible. This is the first study to identify major Yr-genes in Turkish durum wheat varieties and, therefore, these findings can be beneficial in wheat breeding programs to be conducted for resistance to stripe rust.Öğe Virulence characterization of the wheat stripe rust pathogen, Puccinia striiformis f. sp. tritici, in Turkey from 2018 to 2020(Taylor & Francis Inc, 2023) Cat, Ahmet; Tekin, Mehmet; Akan, Kadir; Akar, Taner; Catal, MurselStripe (yellow) rust caused by Puccinia striiformis f. sp. tritici (Pst) is the most devastating disease of wheat in Turkey. Virulence characterization of the Pst population is critical to prevent large-scale epidemics, by developing wheat cultivars with durable resistance against the disease. In this study, 38 Pst races, including 25 races that were not previously reported, were identified from 140 isolates obtained from most regions of Turkey from 2018 to 2020 using a differential set containing 18 single Yr gene wheat lines (NILs) of 'Avocet'. Virulence to Yr15 was not observed among any of the isolates. Virulence to the remaining 17-Yr genes was detected at various frequencies. The frequencies of virulence to Yr6, Yr9, Yr7, Yr8, Yr43, YrExp2, Yr44, YrTr1, and Yr27 were high (57.1 to 100.0%), to Yr1, Yr17, Yr32, and YrTye were moderate (24.3 to 42.9%), and to YrSP, Yr24, and Yr10 were low (9.3 to 17.1%). Only one race was virulent to Yr5 (0.7%). Many of the races identified were common among regions, indicating that Pst races migrate throughout Turkey. However, the Black Sea (BS) and the Mediterranean (ME) regions were differentiated from other regions by unique races absent in other regions, and the Yr5-virulent race, respectively. To sum up, the virulences of the races identified and their distributions among regions provided an understanding of pathogen migration and may contribute to the development of resistant wheat cultivars against stripe rust.
