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ABSTRACT. Effective breeding programs based on genetic diversity are needed to broaden the genetic basis of rice (Oryza sativa L.) in Turkey. In this study, 81 commercial varieties from seven countries were studied in order to estimate the genomic relationships among them using nine interprimer binding site (iPBS)-retrotransposon and 17 simple-sequence repeat (SSR) markers. A total of 59 alleles for the SSR markers and 96 bands for the iPBS-retrotransposon markers were detected, with an average of 3.47 and 10.6 per locus, respectively. Each of the varieties could be unequivocally identified by the SSR and iPBS-retrotransposon profiles. The iPBS-retrotransposon-and SSR-based clustering were identical and closely mirrored each other, with a significantly high correlation (r = 0.73). A neighbor-joining cluster based on the combined SSR and iPBSretrotransposon data divided the rice varieties into three clusters. The population structure was determined using the STRUCTURE software, and three populations (K = 3) were identified among the varieties studied, showing that the diversity harbored by Turkish rice varieties is low. The results indicate that iPBS-retrotransposon markers are a very powerful technique to determine the genetic diversity of rice varieties.

Introduction White tip nematode, Aphelenchoides besseyi, is one of the most widespread nematodes causing economic yield losses in rice-growing areas. White tip nematode is a seed-borne ectoparasite of rice and it has been reported in the majority of the rice-growing countries of Africa; North, Central, and South America; Asia; Europe; and the Pacific. The yield losses caused by this nematode in rice show differences according to rice cultivar, growing year, temperature, cultural practices, and other variable factors. In infested fields, the average yield losses range from 10% to 30%; in fields where all plants have been attacked, yield losses of up to 70% for susceptible cultivars and 20% for resistant cultivars have been reported (Prot, 1992). Aphelenchoides besseyi is an important nematode pest of rice crops in Turkey. It was first reported in 1995 in the İpsala and Gönen districts of Edirne and Balıkesir provinces, respectively (Öztürk and Enneli, 1997). The yield losses have reached up to 57.9% for susceptible cultivar Halilbey in fields having 77% plants with white tips on the infected flag leaves (Tülek and Çobanoğlu, 2010). In several countries, control of this nematode has been achieved using nematode-resistant rice cultivars (Qu, 1985). Differences in susceptibility of rice cultivars to A. besseyi were previously reported in 1949 and appear to have become widespread since then; resistance (Bridge et al., 1990) or moderate resistance in rice cultivars has been observed in most rice-growing regions (Sivakumar, 1988). It has been reported that certain rice cultivars

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ÖzTicari hibrit çeltik ülkemizin için yeni bir kavram olmasına karşın dünyada 1975 yılından beri başarılı bir şekilde kullanılmaktadır. Hibrit çeltik ıslahında ilk aşama ana bitkilerde erkek kısırlık sağlamaktır. Erkek kısırlık için genetik ve genetik olmayan mekanizmalardan yararlanılmaktadır. Bu çalışmanın amacı kimyasal erkek kısırlık (gametosit, CHA, genetik olmayan kısırlık); termogenik erkek kısırlık (TGMS, genetik kısırlık) ve stoplazmik erkek kısırlıktan (CMS, genetik kısırlık) yararlanılarak yerli hibrit çeşit geliştirme olanağının araştırılmasıdır. Bu deneme Edirne ekolojik koşullarında 2013-2014 yıllarında iki yıl yürütülmüştür. Kimyasal kısırlık oluşturmak üzere Paşalı, Halilbey ve Osmancık-97 çeşitlerine sapa kalkma döneminde 1000'er ppm Salisilik Asit (SA), Giberallik Asit (GA3) ve Ethephon (Ethrel) hormonları gametosit olarak uygulanmıştır. Kullanılan çeşitlerde %22-49 arasında erkek kısırlık tespit edilmiştir. Termogenik erkek kısırlık yönteminde TGMS1 ve TGMS2 genotipleri arazi şartlarında denenmiş ve %89-96 arasında erkek kısırlık tespit edilmiştir. Stoplazmik erkek kısırlık yönteminde ise yapılan ölçümler sonucunda V20A, 15A ve 31A CMS çeşitleri %100 kısır olarak tespit edilmiştir. Trakya bölgesinde TGMS sistemi ve uygulan dozlardaki gametositler ticari hibrit geliştirmek için yeterli düzeyde erkek kısırlık oluşturmazken; CMS sistemi %100 kısırlık sağlayan en uygun metot olarak tespit edilmiştir. CMS çeltikler kullanarak ana, baba ve restorer hatlardan oluşan üç hatlı metotla ticari hibrit çeşitlerin geliştirilmesi mümkün görülmektedir. Research on Male Sterility to Commercial Hybrid Rice AbstractCommercial hybrid rice has been utilized effectively around the world since 1975 but it is a new concept for Turkey. First step is to provide the male sterile lines to hybrid breeding system. Genetic and non-genetic mechanisms are available to exploit for male sterility. The aim of this study is identification of utilization of male sterility systems which Chemical Male Sterility (CHA), Thermogenic Genetic Male Sterility (TGMS) and Cytoplasmic Male Sterility for Turkey Ecosystem. This experiment were conducted two years in Edirne ecological conditions in 2013-2014. Chemical Hybridisation Agents (CHA) which salicylic acid, gibberellic acid, Ethephon were sprayed as a gametocide doses 1000 ppm at the booting stage on rice varieties which Paşalı, Halilbey, Osmancık-97. Male sterility was identified 22-49% after applied gametocide in cultivars. TGMS1 and TGMS2 cultivars have 89-96% male sterility in the uncontrolled field situation. CMS lines which V20A, 15A, 31A have been determined 100% male sterility. As a result, TGMS lines and applied doses gametocides are not efficient for male sterility but CMS system is efficient 100% in Trakya region. Japonica type commercial hybrid rice breeding appear possible in Turkey ecological condition using A, B and Restorer Lines.