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 seasonsunder irrigated conditions in Turkey. The analysis of variance showed that mean squares of environments (E), genotypes (G) andGE 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 proposedas reliably growing in test locations for high grain yield. Also, only the Yenisehir location could be best representative of overalllocations for deciding about which experimental hybrids can be recommended for grain yield in this study. Consequently, using ofgrain yield per plant instead of grain yield per plot in hybrid maize breeding programs could be preferred by private companies dueto 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 Çanakkale 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

Exploring the genetic diversity and population structure of wheat landrace population conserved at ICARDA genebank

Landraces are considered a valuable source of potential genetic diversity that could be used in the selection process in any plant breeding program. Here, we assembled a population of 600 bread wheat landraces collected from eight different countries, conserved at the ICARDA's genebank, and evaluated the genetic diversity and the population structure of the landraces using single nucleotide polymorphism (SNP) markers. A total of 11,830 high-quality SNPs distributed across the genomes A (40.5%), B (45.9%), and D (13.6%) were used for the final analysis. The population structure analysis was evaluated using the model-based method (STRUCTURE) and distance-based methods [discriminant analysis of principal components (DAPC) and principal component analysis (PCA)]. The STRUCTURE method grouped the landraces into two major clusters, with the landraces from Syria and Turkey forming two clusters with high proportions of admixture, whereas the DAPC and PCA analysis grouped the population into three subpopulations mostly according to the geographical information of the landraces, i.e., Syria, Iran, and Turkey with admixture. The analysis of molecular variance revealed that the majority of the variation was due to genetic differences within the populations as compared with between subpopulations, and it was the same for both the cluster-based and distance-based methods. Genetic distance analysis was also studied to estimate the differences between the landraces from different countries, and it was observed that the maximum genetic distance (0.389) was between the landraces from Spain and Palestine, whereas the minimum genetic distance (0.013) was observed between the landraces from Syria and Turkey. It was concluded from the study that the model-based methods (DAPC and PCA) could dissect the population structure more precisely when compared with the STRUCTURE method. The population structure and genetic diversity analysis of the bread wheat landraces presented here highlight the complex genetic architecture of the landraces native to the Fertile Crescent region. The results of this study provide useful information for the genetic improvement of hexaploid wheat and facilitate the use of landraces in wheat breeding programs

Nohutta ileri generasyonlarda tane verimi ve tane iriliği için yapılan seçimin etkinliği üzerine bir çalışma

Six chickpea (Cicer arietinum L.) lines derived from single plant selections in both p4 and fs generations were grown with two check varieties in a randomized complete block design with three replicates at Bornova in Izmir during 1996-1997, 1997-1998, 1998-1999 and 1999-2000 growing seasons in winter sowing in order to evaluate the effectiveness of selections for seed yield and seed size in advanced generations of bulk populations. Realized heritabilities and predicted and actual gains from selection for seed yield (kg/da) and 100-seed weight (g) were estimated. Realized heritabilities based on the selection among the lines derived from single plant selections in both generations were in agreement with the realized ones based on the identification of two best lines among these selected lines for the relative effectiveness of selections. Considering the realized heritabilities estimated in both selection stage, it was concluded that selections in F4 -derived lines for seed yield and also in F5-derived lines for 100-seed weight were more effective.İleri kademedeki nohut (Cicer arietinum L.) bulk populasyonlarmda tane verimi ve tane iriliği için yapılan seçimlerin etkinliğini belirleyebilmek amacıyla F4 ve F5 generasyonlarmda tek bitki seçimleriyle oluşturulmuş altışar hat, ikişer kontrol çeşidiyle birlikte Bornova koşullarında dört yıl süreyle (1996-1997, 1997-1998, 1998-1999 ve 1999-2000) üç tekrarlamalı tesadüf blokları desenine göre kurulan denemelerde kışlık olarak yetiştirilmiştir. Tane verimi (kg/da) ve 100-tane ağırlığı (g)için seçimden beklenen ve gerçekleşen kazanç oranlan ile gerçekleşen kalıtım değerleri tahmin edilerek her iki hat grubunda seçimin etkinliği incelenmiştir. Gerek her iki generasyonda tek bitki seçimleriyle oluşturulmuş hatlar arasında yapılan seçimde gerekse seçilen hatlar arasında en iyi ikişer hattın belirlenmesinde gerçekleşen kalıtım derecesi tahminleri benzer sonuçlar vermiştir. Her iki aşamada gerçekleşen kalıtım derecelerine göre ; F4 kökenli hatlarda tane verimi ve F5 kökenli hatlarda da 100-tane ağırlığı yönünden seçimin daha etkili olduğu sonucuna varılmıştır

Melez mısır ( Zea Mays L . ) ıslahında kombinasyon yeteneği kovaryanslarında yaralanma olanağı üzerine bir çalışma

: In this study the possibilities for utilising of combining ability covariances among grain yield per plant, yield components and plant traits in order to identify the most-promising parental inbred lines and crosses vere investigated in two maize (Zea mays L.) populations, one of them consisted of six parental lines and other one did nine inbreds with their half-diallel crosses. Results from general (GCA) and specific (SCA) combining ability covariances among grain yield per plant and other traits indicated that screening the parental lines and crosses based on combining ability effects for J 00 kernel weight and ear length should be effective. It was concluded that combining ability covariances in addition to its variances and effects might be useful in developing hybrid maize.Bu çalışmada, birinde altı diğerinde de dokuz kendilenmiş hat ve, onların yarım diallel melezlerinden oluşan iki mısır populasyonunda bitki dane verimi, verim öğeleri ve bitki özelliklerine ilişkin kombinasyon yeteneği etkileri arasındaki kovaryansların üstün ebeveyn hat ve melezlerin belirlenmesinde kullanılabilme olanakları araştırılmıştır. Bitki verimi ile diğer özellikler arasındaki genel ve özel kombinasyon yeteneği kovaryanslarmdan elde edilen bulgular; verim öğelerinden 100 tane ağırlığı ile koçan uzunluğu için ebeveyn hatlar ve melezler arasında kombinasyon yeteneği değerlerine göre yapılacak seçimlerin daha etkili olabileceğini göstermiştir. Kombinasyon yeteneği varyansları ve etkilerine ek olarak kovaryans tahminlerinin de melez mısır geliştirme çalışmalarında yarar sağlayabileceği sonucuna varılmıştır

Nohutta ileri generasyonlarda verim ile verim ögeleri arasındaki ilişkiler üzerine bir değerlendirme

The possibilities of using the yield components as selection criterion to improve the seed yield were investigated in chickpea (Cicer arietinum L.) bulk populations, The relationships among seed yield per plant and pods per plant, seeds per pc.i and seed weight of individual plants selected from bulk populations in $F_4$ and $F_5$ generations were studied by correlation and path analyses. The effectiveness of identifications among the single plants (genotypes) based on high and low values for yield components on seed yield of their progenies was evaluated. Correlation and path coefficients indicated that the pods per plant mostly influenced the seed yield in both generations. However, it was detected that there were no significant differences between mean seed yields of the progenies of the high and low groups selected for yield components. It was concluded that a yield component should have high heritability in addition to a positive association with grain yield to be used as a selection criteria for high yielded chickpea.Bu çalışmada ileri generasyonlarda nohut (Cicer arietinum L.) bulk populasyonlarmda verim öğelerinin, verimin iyileştirilmesinde seleksiyon ölçütü olarak kullanılabilme olanakları araştırılmıştır. Bu amaçla, $F_4$ ve $_5$F generasyonlarından seçilen tek bitkilerde korelasyon ve path analizleriyle bitki başına tane verimi ve bitkide bakla sayısı, baklada ortalama tane sayısı ve tane ağırlığı arasındaki ilişkiler incelenmiştir. Verim öğeleri bakımından tek bitkiler (genotipler) arasında yapılan seleksiyonlann döl generasyonlannda tane verimi üzerindeki etkinliği değerlendirilmiştir. Korelasyon ve path analizleri, her iki generasyonda da tane verimini en çok, bitkide bakla sayısının etkilediğini göstermiştir. Bununla birlikte, verim öğeleri bakımından yüksek ve düşük değerli olarak belirlenen genotip gruplarının, döl generasyonlarındaki ortalama tane verimleri arasında önemli farklılıkların bulunmadığı gözlenmiştir. Bir verim öğesinin verimi iyileştirme amacıyla seleksiyon ölçütü olabilmesi için verim ile pozitif bir ilişkinin yanısıra kalıtsal bir varyasyona da sahip olması gerektiği sonucuna varılmıştır

Azotlu gübre dozlarının bazı T.dicoccoides w T.durum melezlerinin dane oranına etkisi

This study was carried out in order to determine the effect of fertilization with nitrogen on the grain protein percentage of some T.dicoccoides x T.durum crosses under green house conditions. In experiment conducted in competely randomized design with three replications by factorial arrangement, half of nitrogen in sowing and other one in boot stage were applied in the form of amonium nitrate as 0, 5,10 and 15 kg/da N doses. Results from analysis of variance for grain protein percentage indicated that significant differences among mean values for both nitrogen doses and crosses existed. Also, the fact that dose x cross interaction was significant revealed the effect of fertilization of nitrogen on grain protein percentage varied with cross. For one of the crosses (T.dicoccoides x Gediz-75) fertilization with nitrogen didn't affect the grain percentage but in two crosses (T.dicoccoides x Yavaros and T.dicoccoides x Ege-88), protein percentage was enhanced with increasing amounts of N fertilization. It was found that most appropriate dose was 10 kg/da N for the combination of T.dicoccoides x Altar-84. It was concluded that the results from this study might contribute at some extent to identify the crosses which breeding lines with high protein percentage could be developed.Bu çalışma sera koşullarında yetiştirilen dört T.dicoccoides x T.durum melezinin Fi generasyonunda azotlu gübrelemenin dane protein oranına etkisini incelemek amacıyla yapılmıştır. Basit faktöriyel deneme düzeninde tesadüf parselleri desenine göre üç tekrarlamak olarak kurulan denemede azotun yarısı ekimle yarısı da sapa kalkma döneminde olmak üzere amonyum nitrat formunda 0, 5, 10, ve 15 kg/da N hesabıyla azotlu gübre uygulanmıştır. Dane protein oranına ilişkin varyans analizinden elde edilen bulgular hem azot dozları hem de melezler arasında önemli düzeyde farklılıkların bulunduğunu göstermiştir. Ayrıca melez x doz interaksiyonuna ilişkin varyansm da önemli olması azotlu gübrelemenin danede protein oranına etkisinin meleze göre değiştiğini ortaya koymuştur. Melezlerden birinde (T. dicoccoides x Gediz-75) azotlu gübrelemenin danede protein oranını etkilemediği, iki melezde ise (T.dicoccoides x Yavaros; T.dicoccoides x Ege-88) doz artışlarına paralel olarak danede protein oranının önemli düzeyde arttığı belirlenmiştir. T.dicoccoides x Altar-84 kombinasyonunda ise en uygun azot dozunun 10 kg/da olduğu saptanmıştır. Çalışmadan elde edilen bulguların danede yüksek protein oranına sahip hatların geliştirilebileceği bazı .melezlerin belirlenmesinde bir ölçüde katkıda bulunabileceği sonucuna varılmıştır