The effects of the plant growth regulator trinexapac-ethyl (TE), conjoined with different seeding rates of rice (Oryza sativa L.) milling yields, were evaluated in Turkey between 2009 and 2010. Two rice cultivars (Osmancık-97 and Karadeniz), three seeding rates (400, 500, and 600 seeds m-2), and four doses of TE (0, 100, 200, and 300 g ai ha-1) were compared. The experiments were designed in a randomized block in factorial ordering with 3 replicates. Quality factors including head, cargo, and total rice milling yields, 1000 grain weight, and lodging score were evaluated. Head rice milling yield was affected significantly; however, no statistically significant difference was seen with respect to cargo rice and total milled rice by TE dose. The effect was predicted to depend on grain weight and lodging, which decreased rice milling yield. Seeding rate did not have a significant impact on milling yields. There was a significant correlation between milling yields (head rice and total milled rice but not cargo rice) and both 1000-grain weight and lodging. A seeding rate of 500 seeds m-2 was the optimum value among all seeding rates, and the highest milling yields were obtained from Osmancık-97. Irrespective of genotype and seeding rate, treatments with 100, 200, and 300 g TE ai ha-1 increased head rice milling yield. All doses of TE reduced 1000 grain weight and lodging. Regression analysis revealed that increasing TE doses raised head rice milling yield.

Background: Non-transgenic chemical mutagen application, particularly ethyl methanesulfonate (EMS), is an important tool to create mutations and gain a new genetic makeup for plants. It is useful to obtain a sufficient number of mutant plants instead of working with a severe mutation in a few plants. EMS dose and exposure period have been previously studied in several crops; however, EMS used to create point mutations in presoaked rice seeds has not been sufficiently studied and there is no standard protocol for such treatment. The aim of this study is to establish a standard protocol for EMS mutagenesis application in rice. Methods: Two studies were conducted to evaluate the effect of four durations of rice seed presoaking (0, 6, 12, and 24 hours), four EMS concentration doses (0.0%, 0.5%, 1.0%, and 2.0%), and four EMS exposure periods (6, 12, 24, and 48 hours). Germination rate, plumula and radicle length, seedling survival, shoot length, root length and fresh seedling weight were evaluated. Results: Results showed that a 12-hour presoaking duration, 0.5% EMS dose, and six hours of EMS exposure were the best practices for the optimum number of mutant plants. Conclusions: In light of both this study and the literature, a standard application protocol was established. This application protocol, detailed in this article, contains the following guidelines: (1) Presoaking: 12 hours, (2) EMS application: 0.5% dose EMS and six hours, (3) Final washing: six hours, (4) Drying: 72 hours at 38°C. A user-friendly protocol has been presented for utilization by researchers.

Hybrid rice has an average 15% to 20% yield advantage over inbred lines. The accessibility of stable cytoplasmic male sterility system (CMS) is vital for commercial hybrid rice. The experiment was conducted to develop japonica type CMS lines of national rice varieties. National varieties were tested to determine as maintainer, CMS or restorer features via test cross. The test crosses were made by using 19 japonica type national rice varieties and 21 CMS lines and 1 restorer line. All national rice varieties which tested are determined maintainer features. In addition, 8 CMS introduction lines and 1 restorer lines adapted Mediterranean ecological condition for hybrid breeding process. Two maintainer were backcrossed for 6 generations and it was developed similar agronomic features and 100% spikelet sterile CMS lines. For production of CMS lines Osmancik-97 and Kiziltan, it was employed wild abortive rice which is CMS V20A. Successive backcrossing of varieties succeeded to produce completely male sterile CMS lines. Wild abortive cytoplasm did not affect agronomic characteristic. Osmancik-97 and Kiziltan were utilized as a recurrent parent in breeding program due to their popularity, and the new WA-CMS lines might be useful for hybrid rice breeding. CMS-Osmancik-97 and CMS-Kiziltan are the first developed national CMS rice lines in Turkey.

Background: Non-transgenic chemical mutagen application, particularly ethyl methanesulfonate (EMS), is an important tool to create mutations and gain a new genetic makeup for plants. It is useful to obtain a sufficient number of mutant plants instead of working with a severe mutation in a few plants. EMS dose and exposure period have been previously studied in several crops; however, EMS used to create point mutations in presoaked rice seeds has not been sufficiently studied and there is no standard protocol for such treatment. The aim of this study is to establish a standard protocol for EMS mutagenesis application in rice. Methods: Two studies were conducted to evaluate the effect of four durations of rice seed presoaking (0, 6, 12, and 24 hours), four EMS concentration doses (0.0%, 0.5%, 1.0%, and 2.0%), and four EMS exposure periods (6, 12, 24, and 48 hours). Germination rate, plumula and radicle length, seedling survival, LD50 (Lethal Dose) determination, shoot length, root length and fresh seedling weight were evaluated. Results: Results showed that a 12-hour presoaking duration, 0.5% EMS dose, and six hours of EMS exposure were the best practices for the optimum number of mutant plants. Conclusions: In light of both this study and the literature, a standard application protocol was established. This application protocol, detailed in this article, contains the following guidelines: (1) Presoaking: 12 hours, (2) EMS application: 0.5% dose EMS and six hours, (3) Final washing: six hours, (4) Drying: 72 hours at 38°C. A user-friendly protocol has been presented for utilization by researchers.

This study aimed to evaluate the cold stress effect in natural field conditions by employing different rice sowing timings over three years, to identify national varieties tolerant to cold stress at the vegetative and generative stages, and to propose a data-derived solution regarding termination and resowing due to cold stress conditions. Early, regular, and late sowing dates were employed to capture natural cold stress conditions in a 3-year-long experiment. Sowing dates resulting in the greatest yields fluctuated from regular to late sowing dates, according to the stress duration in cold stress years. Yield losses resulting from cold stress ranged from 0.810 to 2.740 t ha-1 and reached 38.6%. ‘Halilbey,’ ‘Pasali,’ and ‘Mevlutbey’ were found to be most cold-tolerant varieties. Grain yield was correlated with plant number; the critical minimum level was between 60.8 and 79.6 plants m-2 and the optimum was 132.3 plants m-2 for economical yield. Cold stress negatively affected rice plant density, and plant densities below the critical minimum plant warranted crop termination and resowing, depending on application costs. Cold stress had a far more devastating effect on germination and seedling stages than on later development stages in temperate conditions.

Çeltik tropikal bir bitki olup soğuktan olumsuz yönde etkilenmektedir, bununla birlikte Türkiye gibi ılıman iklim bölgelerinde tarımı yapılmaktadır. Bu çalışma bazı çeltik genotiplerinde generatif dönemde kontrollü şartlarda oluşturulan soğuk stresinin etkilerini belirlemek amacıyla yapılmıştır. Deneme 13 çeltik genotipi üzerinde Edirne Trakya Tarımsal Araştırma Enstitüsünde 2013, 2014 ve 2015 yıllarında yürütülmüştür. Generatif dönemdeki çeltikler bitki büyütme kabininde 8 gün boyunca 9 °C soğuk uygulaması yapılmış ve sera ortamına transfer edilerek olgunlaşma dönemi sonunda hasat edilmiştir. Deneme tesadüf parselleri deneme deseninde 3 tekerrürlü olarak yürütülmüştür. Hasatta sterilite ölçümü yapılarak genotipler generatif dönem soğuk stresi yönünden sınıflandırılmıştır. Sonuçta kontrol uygulamasında % 11.3 sterilite ölçülürken, soğuk uygulamasında % 30.8 sterilite ölçülmüştür. Soğuk stresi sterilite oranını % 272.6 artırmıştır. Indika tipi çeltiklerin Japonika tipi çeltiklere göre daha hassas oldukları gözlenmiştir. Tunca, Hamzadere ve IR50 çeşitleri hassas olarak belirlenirken, Paşalı, Mevlütbey ve Halilbey çeşitleri toleranslı olarak belirlenmiştir. Ayrıca moleküler tekniklerle, üç, yedi ve dokuzuncu kromozom üzerinde bulunan üç farklı QTL (Kantitatif Özellik Lokusu) bölgesi taranarak generatif dönemde soğuk toleransı incelenmiştir. Moleküler sonuçlarla morfolojik sonuçların benzer olduğu tespit edilmiştir. Generatif dönemde soğuk stresi yaşanan bölgelerde seçilen çeşitlerin kullanılması tavsiye edilmektedir.

Bu araştırmanın amacı, Trakya koşullarının farklı lokasyonlarında, çeltik genotiplerinin performansını belirlemek ve bazı karakterler yönünden stabilitelerini tespit etmektir. Çalışmada, 14 çeltik genotipi kullanılmıştır. Bu genotipler, 2013 ve 2014 yıllarında, Trakya bölgesinde bulunan, Edirne Merkez ve İpsala ilçeleri ile Tekirdağ'ın Hayrabolu ilçesinde tesadüf blokları deneme deseninde 3 tekerrürlü olarak yürütülmüştür. Araştırmada, genotiplerin çeltik tane verimi, çeltik ve pirinç 1000 tane ağırlıkları ile kırıklı ve kırıksız pirinç randımanı değerleri incelenmiştir. Bu özellikler bakımından çeşitler arasında önemli farklılıklar tespit edilmiştir. Aynı zamanda, bu karakterler yönünden çevre ve genotipxçevre interaksiyonları önemli bulunmuştur.

Background: Non-transgenic chemical mutagen application, particularly ethyl methanesulfonate (EMS), is an important tool to create mutations and gain a new genetic makeup for plants. It is useful to obtain a sufficient number of mutant plants instead of working with a severe mutation in a few plants. EMS dose and exposure period have been previously studied in several crops; however, EMS used to create point mutations in presoaked rice seeds has not been sufficiently studied and there is no standard protocol for such treatment. The aim of this study is to establish a standard protocol for EMS mutagenesis application in rice. Methods: Two studies were conducted to evaluate the effect of four durations of rice seed presoaking (0, 6, 12, and 24 hours), four EMS concentration doses (0.0%, 0.5%, 1.0%, and 2.0%), and four EMS exposure periods (6, 12, 24, and 48 hours). Germination rate, plumula and radicle length, seedling survival, LD50 (Lethal Dose) determination, shoot length, root length and fresh seedling weight were evaluated. Results: Results showed that a 12-hour presoaking duration, 0.5% EMS dose, and six hours of EMS exposure were the best practices for the optimum number of mutant plants. Conclusions: In light of both this study and the literature, a standard application protocol was established. This application protocol, detailed in this article, contains the following guidelines: (1) Presoaking: 12 hours, (2) EMS application: 0.5% dose EMS and six hours, (3) Final washing: six hours, (4) Drying: 72 hours at 38°C. A user-friendly protocol has been presented for utilization by researchers.