Fatma Aykut Tonk

Chemical and genetic variability of selected Turkish oregano (Origanum onites L.) clones

Turkish oregano (Origanum onites L.) is a major aromatic plant that belongs to Labiatae family. In this work fourteen Turkish oregano clones have been characterized chemically and genetically. Essential oil obtained by hydro-distillation was characterized by gas chromatography. Genetic variation was determined by use of random amplified polymorphic DNA (RAPD) markers. Variation of essential oils in the selected clones was subjected to cluster analysis, and two chemotypes, carvacrol and thymol, were identified. Carvacrol was found to be the main component in all clones except clone-661, the main component of which was thymol. The oregano clones were divided into three main groups by clustering on the basis of RAPD markers. Genetic similarity values among the oregano clones ranged between 0.49 and 0.73 which was indicative of a low level of genetic variation. Clones originating from locations close to each other had similar RAPD markers. Correlation analysis of the genetic distance matrix and the Euclidian distance matrix revealed no significant correlation between them. The results also indicated that there is no relationship between genetic structure of the selected clones and essential oil composition.

Evaluation of genotype x environment interactions in maize hybrids using GGE biplot analysis

Seventeen hybrid maize genotypes were evaluated at four different locations in 2005 and 2006 cropping seasons under irrigated conditions in Turkey. The analysis of variance showed that mean squares of environments (E), genotypes (G) and GE interactions (GEI) were highly significant and accounted for 74, 7 and 19 % of treatment combination sum squares, respectively. To determine the effects of GEI on grain yield, the data were subjected to the GGE biplot analysis. Maize hybrid G16 can be proposed as reliably growing in test locations for high grain yield. Also, only the Yenisehir location could be best representative of overall, locations for deciding about which experimental hybrids can be recommended for grain yield in this study. Consequently, using of grain yield per plant instead of grain yield per plot in hybrid maize breeding programs could be preferred by private companies due to some advantages.

Identification of resistance to Eurygaster integriceps Put. on some bread wheat genotypes

Sunn pest ( Eurygaster integriceps Put.) is one of the most important pests of wheat in Eastern Europe including Turkey, West and Cen-tral Asia. Its damage on leaves, stems, spikes and grains reduce the baking quality of flour made from damaged grains. In this study, some wheat genotypes from Turkey and ICARDA were evaluated for the pest resistance. The genotypes were planted in a randomized block design using hill plots in nylon mesh screening cages in wheat growing season of 2011-2012 and 2012-2013. Sunn pest population was collected from Canakkale province, where the pest was intensely found in recent years. The plants of each hill plots were infested with one male and one female Sunn pest adults. The results with 12.5% sucking damage showed that the genotypes from ICARDA had higher resistance than the landraces from Turkey to Sunn pest. Especially, the genotypes IC3 and IC4 from ICARDA and TR7 from Turkey with respect to their SED and DSED values were found the most promising genotypes resistant to Sunn pest for future breeding programs.

Tatlı Mısırın Kalite Kriterlerine Göre Optimum Hasat Zamanının Belirlenmesi

Bu calismada, uc farkli zamanda (6 Mayis, 20 Temmuz ve 20 Agustos) ekilen, uc farkli tatli misir cesidinin (Sunshine, El toro ve Merkur) uc farkli donemde (sut olum, sari olum ve hamur olum) hasat edilmesi sonucu elde edilen tatli misirlarin kalite kriterlerinin belirlenmesi ve bu kriterlere gore optimum hasat zamaninin saptanmasi uzerine calisilmistir. Her ekim zamaninda, her cesitten uc farkli hasat doneminde misir ornekleri hasat edilmis ve tanelenmistir. Tane boyut olcumu, 1000 tane agirligi, toplam kuru madde, nisasta, suda cozunur kuru madde, seker, tekstur, renk degerleri (L*, a*, b*), protein ve duyusal analizleri yapilmistir. Arastirma sonucunda,. Hasat donemleri geciktikce tane boyutlari, 1000 tane agirligi, toplam kuru madde, nisasta, tekstur, L*, a*, b*, protein degerleri artmis ve suda cozunur kuru madde, seker degerleri azalmistir. Invert seker, toplam seker, nisasta ve duyusal analizlerden lezzet ozelliklerine gore optimum hasat donemleri Sunshine cesidi icin Mayis ekim zamaninda sut olum hasat donemi icin (ekimden hasada kadar gecen sure ) 83 gun, Temmuz ekim icin sure 72 gun ve Agustos ekimi icin 89 gun olarak belirlenmistir. Merkur cesidi icin Mayis ekim zamaninda sut olum hasat donemi (ekimden hasada kadar gecen sure) icin 87 gun, Temmuz icin 77 gun ve Agustos ekimi icin 107 gun olarak belirlenmistir. El toro cesidi icin ise optimum hasat donemleri Mayis ekim zamaninda sut olum hasat donemi (ekimden hasada kadar gecen sure) icin 89 gun, Temmuz ekimi icin 79 gun ve Agustos ekimi icin 100 gun olarak belirlenmistir.

İki Ekmeklik Buğday (Triticum aestivum L.) Melezinde Bazı Verim Komponentlerinin Gen Etkileri

Bu calismada, iki ekmeklik bugday melezinde (Basribey x 3 nolu hat, Golia x 3 nolu hat) ebeveynler (P1 ve P2), F1, F2 ve her iki ebeveynle yapilan geriye melez (BC1 ve BC2) generasyonlari kullanilarak basakta tane sayisi, bin tane agirligi ve tek bitki verimi ozelliklerinin kalitiminda rol oynayan gen etkilerinin saptanmasi amaclanmistir. Olusturulan populasyonlarda genetik analizler uc parametreli birlesik olcumleme testi ve alti parametre yontemi ile gerceklestirilmistir. Her iki melez kombinasyonda da basakta tane sayisi ve tek bitki verimi ozelligi bakimindan eklemeli-dominant modelin yeterli oldugu, bin tane agirligi ozelligi acisindan da populasyonlarda eklemeli ve dominant gen etkileri ile beraber epistatik gen etkilerinin de bulundugu anlasilmaktadir. Bu nedenle bu populasyonlarda basakta tane sayisi ve tek bitki verimi ozellikleri icin erken generasyonlarda, bin tane agirligi ozelligi icin ise ileriki generasyonlarda seleksiyona baslanmasinin daha etkili olabilecegi sonucuna varilmistir