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Unan R.,Trakya Agricultural Research Institute | Sezer I.,Ondokuz Mayis University | Sahin M.,The Central Research Institute for Field Crops | Mur L.A.J.,Aberystwyth University
Turkish Journal of Agriculture and Forestry | Year: 2013

In this study, the effects of the plant growth regulator trinexapac-ethyl (TE) combined with different sowing densities on fieldgrown rice (Oryza sativa L.) plant length, lodging, and grain yield were evaluated over 2 growing seasons. Two different rice cultivars (Karadeniz and Osmancik-97), 3 different sowing densities (400, 500, and 600 seeds m-2), and 4 different doses of TE (0, 100, 200, and 300 g ai ha-1) were compared. The experiments were designed in a randomized block design in factorial ordering with 3 replicates. An increase in sowing density led to an increase of lodging, but it did not have a significant impact on plant length and grain yield. There was a significant correlation between lodging and plant length. A sowing density of 500 seeds m-2 is the optimum value among all sowing densities, and the highest yield was obtained from Osmancik-97 among all the cultivars. Irrespective of genotype and sowing density, treatments with 100 and 200, but not 300, g TE ai ha-1 increased rice yield. All doses of TE reduced lodging and plant length. By regression analyses, the optimal TE dose was predicted to be 170 g ha-1. © TÜBİTAK.

The genetic diversity of Pyrenophora graminea, the causal agent of barley leaf stripe disease, was characterized by restriction fragment length polymorphism (RFLP) of the rDNA internal transcribed spacer region and intersimple sequence repeat (ISSR) analysis. A total of 45 P. graminea isolates recovered from different geographic origins and barley cultivars or genotypes produced identical RFLP banding patterns with HinfI, MspI, Hin6I and BsuRI restriction enzymes. ISSR analysis indicated that there was little genetic variability among the isolates. A dendrogram based on Jaccard's coefficient separated the isolates into 4 clusters with 12% dissimilarity. In the dendrogram, the isolates collected from different geographic regions in Turkey were clustered separately from the Italian isolates. These results indicated that the Turkish isolates of P. graminea were genetically homogeneous and may be derived from a single gene pool. In addition, 13 isolates were tested for pathogenic variability on 48 barley cultivars. The cultivars Durusu, Balkan 96 (Igri), Çumra 2001 and Anadolu 98 were found to be resistant to all leaf stripe isolates. © TÜBİTAK.

Bayraktar H.,Ankara University | Ozer G.,Abant Izzet Baysal University | Aydogan A.,The Central Research Institute for Field Crops | Palacoglu G.,Ankara University
Journal of Plant Diseases and Protection | Year: 2016

Ascochyta blight is a devastating disease of chickpea caused by Ascochyta rabiei. In this article, we described a real-time PCR assay for the determination and quantification of A. rabiei infection in chickpea tissues and accurate monitoring of disease progression in plant materials inoculated with different inoculation methods. The primer pairs HEF1/HEF2 were designed to anneal to conserved regions of translation elongation factor 1 alpha (EF) gene for specific amplification of 82-bp fragment of A. rabiei based on SYBR Green I technology. The detection limit of assay was determined as 0.1 pg DNA. PCR specificity was confirmed by testing against uninfected chickpea tissues and another fungal species associated with chickpea. The chickpea plants were inoculated by the methods of whole-plant and detached leaflet inoculation. Disease progression in resistant and susceptible cultivars was evaluated at certain time intervals after pathogen inoculation by real-time PCR. The results revealed a good correlation between visual assessments of disease reaction and pathogen quantification in infected chickpea tissues. The target DNA sequence was also amplified from the samples of DNA extracts from artificially infested seed. This technique could provide a useful approach for efficient selection of resistant breeding material in an early stage of infection as an alternative to the visual disease assessment and will be also used for the determination and quantification of A. rabiei infection. © Deutsche Phythomedizinische Gesellschaft 2016.

Mert Z.,The Central Research Institute for Field Crops | Karakaya A.,Ankara University | Dusunceli F.,The Central Research Institute for Field Crops | Akan K.,The Central Research Institute for Field Crops | Cetin L.,The Central Research Institute for Field Crops
Turkish Journal of Agriculture and Forestry | Year: 2012

Stem rust, caused by the fungus Puccinia graminis f. sp. tritici (Pgt), is one of the most important diseases limiting wheat production in Turkey. Surveys were conducted in 2007 and 2008 in order to determine the races of the pathogen present in Turkey. In 2007, it was found that 91 (43%) out of 207 inspected wheat fields were infected with stem rust, and in 2008, it was found that 61 (25%) out of 242 inspected fields were infected. From these samples, 40 single pustule isolates were obtained. The North American differential set, which includes 20 genotypes with different resistance genes, was employed to identify the races present. Seedling tests were used for race analysis under greenhouse conditions. A total of 21 different stem rust races were found. Pgt race TKTTC, which was found in 11 Pgt isolates, was the most common race. Genotypes possessing at least 1 of the Sr24, Sr31, Sr26, and Sr27 resistance genes showed low infection types for 40 Pgt isolates. The resistance genes determined in this study could be used in breeding programs for developing stem rust-resistant genotypes. © TÜBITAK.

Dusunceli F.,Food and Agriculture Organization | Stocchi A.,Food and Agriculture Organization | Scaduto C.,Food and Agriculture Organization | Mancini F.,Food and Agriculture Organization | And 10 more authors.
EPPO Bulletin | Year: 2015

Rust diseases (Puccinia spp.), namely stripe, leaf and stem rusts, are among the major diseases of wheat. Their management requires integrated approaches including timely surveillance, speedy communication and rapid response. This surveillance system was developed in order to facilitate participation of extension offices (in provinces/districts) in the survey of wheat rust diseases and sharing of information quickly. The SMS based system was tested as a pilot tool in the Central Anatolia region of Turkey connecting 25 districts in 5 provinces through an SMS network during the rust development period (April-July) in 2013. The observations from 268 fields indicated that leaf rust and stem rust development was insignificant in the districts covered, occurring in only 2.3% and 1.9% of the fields respectively. Stripe rust prevalence was higher occurring in 44.8% of the fields. Of the inspected fields 2.5% had infected plant incidences between 15% and 40% requiring control measures. Using the SMS reports received from the extension officers, the system facilitated daily monitoring of rust development and exchange of observations among the relevant institutions, also sending out alert messages to designated authorities as necessary. The study demonstrated that the system can serve as a rapid surveillance and communication tool to facilitate timely decision making and rapid response to prevent wheat rust epidemics. © 2015 Organisation Européenne et Méditerranéenne pour la Protection des Plantes/European and Mediterranean Plant Protection Organization.

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