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Öğe Buğdayda Puccinia Striiformis F. Sp. Tritici Irklarının Moleküler Tanımlanması ve Sarı Pasa Dayanıklılık Sağlayan Genlerin Piramitlenmesi(2021) Çatal, Mürsel; Aksoy, Aytekin; Akan, Kadir; Akar, Taner; Tekin, Mehmet; Çat, AhmetÜlkemiz için en stratejik tarım ürünlerinden biri olan buğdayda büyük oranda verim ve kalite kayıplarına yol açan hastalıkların başında sarı pas hastalığı gelmektedir. Bu hastalığın etmeni obligat bir parazit olan Puccinia striiformis f. sp. tritici (Pst)?dir. Bu çalışmanın birincil amacı ülkemizde yayılış gösteren Pst ırklarının hem tek bir dayanıklılık geni bakımından farklılaşan izogenik hatlardan oluşan ırk ayırıcı set ile virülens hem de yeni nesil dizileme yöntemi ile moleküler düzeyde tanımlanmasıdır. Bu sayede bölgeler düzeyinde Pst ırklarındaki mevcut durum ile bölgeler arasındaki değişimin incelenmiştir. Bunun yanında, küresel düzeyde Pst ırklarına dayanım sağladığı bilinen dayanıklılık genlerinin (Yr5, Yr10 ve Yr15) ticari olarak yaygın ekilen bir yazlık ekmeklik buğday çeşidine (Sagittario) aktarılması ile her bir dayanıklılık genini taşıyan izogenik hatların geliştirilmesi ve dayanıklılık genlerinin bu çeşitte piramitlenmesi projenin diğer bir amacını oluşturmaktadır. Çalışma kapsamında toplanan Pst izolatları ile yapılan ırk analizi sonucunda ülkemizde 38 Pst ırkı tanımlanmıştır. Ülkesel düzeyde en yaygın ırkın PSTr-29 (%22.70) olduğu bu ırkı ise PSTr-30 (%17.02), PSTr-31 (%12.77) ve PSTr-28 (%7.10) ırklarının takip ettiği belirlenmiştir. Diğer ırkların frekansı ise %0.71 ile %2.83 arasında değişmiştir. En fazla Pst ırkının bulunduğu bölgeler ise sırasıyla İç Anadolu (15 ırk), Marmara (14 ırk), Güneydoğu Anadolu (10 ırk), Ege (9 ırk), Akdeniz (6 ırk) ve Karadeniz (5 ırk) olarak belirlenmiştir. Ayrıca Ege ve Akdeniz bölgelerindeki en yaygın ırk PSTr-30 olarak belirlenirken PSTr-29 ırkı İç Anadolu, Güneydoğu Anadolu ve Karadeniz bölgelerindeki en yaygın ırk olarak tespit edilmiştir. Marmara bölgesindeki en yaygın ırk ise PSTr-28 olarak belirlenmiştir. Öte yandan Karadeniz bölgesinde yüksek frekans değeri ile en yaygın ırklardan biri olan PSTr-29, bölge-özel ırk olarak öne çıkmıştır. Pst izolatlarının dayanıklılık genleri üzerine virülanslıkları ise oldukça farklılık göstermiştir. Çalışmada kullanılan 140 izolatın tümü Yr15 genine avirülent iken Yr6 genine virülent bulunmuştur. Öte yandan çalışma kapsamında ülkemizde ilk defa Yr5 dayanıklılık genine virülent bir ırk tespit edilmiştir. Gerçekleştirilen ıslah çalışmaları sonucunda sarı pas hastalığına dayanıklılık sağlamak için ülkemizde yürütülecek ıslah programlarında kullanılmak üzere izogenik hatlar geliştirilmiştir. Ayrıca ikili melezler sonucu elde edilmiş ve her biri iki dayanıklılık geni taşıyan birçok hat elde edilmiştir. Özellikle ülkemizin yazlık dilimi için uygun özellikleri taşıyan yani gün uzunluğu hassasiyeti olmayan (Ppd-D1a alleli taşıyan), vernalizasyon genleri bakımından yazlık karakterde (Vrn-A1 ve Vrn-D1 allellerini taşıyan), yarı bodur (Rht-B1b alleli taşıyan) ve yüksek gluten kalitesine sahip (Glu-Ax2* allelini taşıyan) Sagittario/Yr5//Sagittario/Yr15 kombinasyonundan umutvar bir hat bulunmaktadır. Sonuç olarak yürütülen bu çalışmanın bundan sonra sarı pas hastalığı üzerine yürütülecek çalışmalar için kıymetli bir veritabanı oluşturduğu düşünülmektedir. Ayrıca belirteç destekli gen piramitlemesi ile geliştirilen hattın genotipik açıdan istenen özelliklere sahip olması dolayısıyla ülkemizin yazlık dilimi için önemli bir çeşit adayı olacağı düşünülmektedir.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 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 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.
