Wheat breeders in Turkey have been developing new varieties since the 1920s, but few studies have evaluated the rates of genetic improvement. This study determined wheat genetic gains by evaluating ...22 winter/facultative varieties released for rainfed conditions between 1931 and 2006. The study was conducted at three locations in Turkey during 2008–2012, with a total of 21 test sites. The experimental design was a randomized complete block with four replicates in 2008 and 2009 and three replicates in 2010–2012. Regression analysis was conducted to determine genetic progress over time. Mean yield across all 21 locations was 3.34tha−1, but varied from 1.11tha−1 to 6.02tha−1 and was highly affected by moisture stress. Annual genetic gain was 0.50% compared to Ak-702, or 0.30% compared to the first modern landmark varieties. The genetic gains in drought-affected sites were 0.75% compared to Ak-702 and 0.66% compared to the landmark varieties. Modern varieties had both improved yield potential and tolerance to moisture stress. Rht genes and rye translocations were largely absent in the varieties studied. The number of spikes per unit area decreased by 10% over the study period, but grainsspike−1 and 1000-kernel weight increased by 10%. There were no significant increases in harvest index, grain size, or spike fertility, and no significant decrease in quality over time. Future use of Rht genes and rye translocations in breeding programs may increase yield under rainfed conditions.
The study estimated genetic gain for yield and other traits in winter wheat released for irrigated environments in Turkey from 1963 to 2004. Yield trials including 14 varieties were grown in 16 ...environments from 2008 to 2012 in provinces of Konya, Eskişehir, Ankara, and Edirne. The highest yields were achieved by recent varieties Kinaci-97 (5.48tha−1), Cetinel-2000 (5.39tha−1), Alpu-2001 (5.44tha−1), Ahmetaga (5.35tha−1), and Ekiz-2004 (5.42tha−1) compared to older varieties Yektay-406 (4.17tha−1) and Bezostaya-1 (4.27tha−1) released in the 1960s. The progress reached in grain yield in 20years was 1.16tha−1 or 58kgha−1 (1.37%) per year. This gain was mainly achieved through shorter plant height and increased harvest index. There was no clear tendency of changes in specific yield components demonstrating that new high-yielding varieties may have different ways to reach their yield potentials. The yield gains were accompanied by improved stripe rust and leaf rust resistances primarily based on adult plant resistance genes. The grain quality of the new varieties did not deteriorate over time although most of them were inferior to the bread-making quality check Bezostaya-1, a feature that may require attention in future breeding.
Developing varieties adapted to dry conditions is one of the biggest targets for breeders. It is important to use inexpensive spectral sensing methods saving time in variety development. The aim of ...this study was to select bread wheat genotypes having high grain yield by using spectral sensing methods. Twenty-five bread wheat (Triticum aestivum L.) genotypes were evaluated under rainfed condition at three locations in Central Anatolia Region. The experiment was arranged in randomized complete block design with three replications. Grain yield (GY), Canopy Temperature (CT), Soil Plant Analysis Development (SPAD) and Normalized Difference Vegetation Index (NDVI) values were recorded. GY, CT, SPAD and NDVI were found to be statistically significant in terms of both genotype and environment. The relationship between grain yield and NDVI (R2=0.321**) values was linear. The positive correlation of GY (0.5671**) and SPAD (0.1729*) with NDVI suggest that NDVI can be used as efficient and precise selection criteria for identifying high effiency wheat varieties under rainfed conditions.
Developing varieties adapted to dry conditions is one of the biggest targets for breeders. It is important to use inexpensive spectral sensing methods saving time in variety development. The aim of this study was to select bread wheat genotypes having high grain yield by using spectral sensing methods. Twenty-five bread wheat (Triticum aestivum L.) genotypes were evaluated under rainfed condition at three locations in Central Anatolia Region. The experiment was arranged in randomized complete block design with three replications. Grain yield (GY), Canopy Temperature (CT), Soil Plant Analysis Development (SPAD) and Normalized Difference Vegetation Index (NDVI) values were recorded. GY, CT, SPAD and NDVI were found to be statistically significant in terms of both genotype and environment. The relationship between grain yield and NDVI (R2=0.321**) values was linear. The positive correlation of GY (0.5671**) and SPAD (0.1729*) with NDVI suggest that NDVI can be used as efficient and precise selection criteria for identifying high effiency wheat varieties under rainfed conditions.
This study was conducted to determine the farinograph parameters and some quality characteristics of 15 bread wheat varieties grown in rainfed conditions in 2011-2012, 2012-2013 and 2013-2014 ...according to a randomized block trial design with two replication. The farinograph parameters (development time, water absorption, stabilsity and softening at the 12th minute), protein ratio, grain hardness, Zeleny sedimentation and bread volume of bread wheat varieties were investigated. Three-year average value ranges of quality traits; protein ratio 13.51-16.02%, grain hardness PSI 45.74-71.05, Zeleny sedimentation 34.67-63.67 ml, bread volume 340-519.17 cm3, farinograph development time 3.75-12.30 min., farinograph water absorption 57.43-65.72%, farinograph stability 4.62-16.92 min. and the farinograph 12 min. softening value 38.66-132.33% was determined as. Significant quality differences were determined between varieties and years, and the highest values in terms of quality traits were obtained in 2013-2014. High values were obtained in Konya-2002, Tosunbey, Karahan-99 and Eraybey varieties in terms of farinograph development time, water absorption and stability values.
2002-2003 yılı yetiştirme döneminde, 9 çevrede denenen 25 ekmeklik buğday genotpnin tane verimi değerlerine. GGE-biplot analizi (G, genotip +- GEl. genotip çevre interaksiyonu uygulanmıştır. Toplam ...varyasyonun (G + E + GEl % 81 'ini E, % 7.3 ünü G ve % 11.7'sini ise GEl açıklamıştır. Biplotu oluşturmak için kullanılan ilk iki ana bileşen (PC1 ve PC2). GGE kareler toplamının % 46.2 ve % 15.8'inı oluşturmuştur. PCI değerleri >0 olan genotipler yüksek verimli ve/veya uyumlu iken, PC1 değerleri <0 olan genotipler ise düşük verimli ve/veya uyum sağlayamayanlar olarak beklenmiştir. Genotiplerin PC1 değerlerinden farklı olarak, sıfıra yakın PC2 değerleri stabil genotiplerle ilgili iken. mutlak değerleri büyük olan PC2 değerleri ise stabilitesi düşük genotiplerle ilgili olmuştur. Diğer taraftan çevrelerin PC1 değerleri, çapraz olmayan GEl, PC2 değerleri ise çapraz GEl'ne işaret etmiştir. Denemede G7. G19 ve G24 genotiplerinin yüksek verimli ve stabil oldukları belirlenmiştir. Orta Anadolu Platosundan örneklenen deneme çevreleri iki büyük çevreye (ME1 ve ME2 ayrılmış, E1 (Konya), E3 (Obruk, E5 (Haymana) ve E8 (Uşak) ilk büyük çevreyi (ME1, E2 (Çumra). E4 (Ereğli, E6 (Ulaş, E7 (Eskişehir) ve E9 (Albntaş ise ikinci büyük çevreyi (ME2) oluşturmuştur. Diğer taraftan E2 (Çumra) ise tüm deneme çevrelerini temsil etme ve denenen genotipleri en güçlü ayırma özelliğine sahip olmuştur.
Yield data of 25 bread wheat genotypes tested across 9 rain-fed environments during the 2002-2003 growing season were analyzed using the GGE (i.e. G, genotype + GE1, genotype-by-environment interaction) biplot method. E (environment) explained 81% of the total (G + E + GE) variation, whereas G and GEI captured 7.3% and 11.7%, respectively. The first 2 principal components (PCI and PC2) were used to create a 2-dimensional GGE-biplot and explained 46.2% and 15.8% of GGE sum of squares (SS), respectively. Genotypic PCI scores >0 detected the adaptable and/or higher-yielding genotypes, while PCI scores <0 discriminated the non-adaptable and/or lower-yielding ones. Unlike genotypic PC1 scores, near-zero PC2 scores identified stable genotypes, whereas absolute larger PC2 scores detected the unstable ones. On the other hand, environmental PCI scores were related to non-crossover type GEIs and the PC2 scores to the crossover type. Of the tested genotypes, G7, G19 and G24 were desirable in terms of higher yielding ability and stability. Nine test environments were sampled from the Central Anatolian Plateau and constituted 2 mega-environments (ME1 and ME2). The former included environments El (Konya), E3 (Obruk), E5 (Haymana) and E8 (Uşak), and the latter included E2 (Çumra), E4 (Ereğli), E6 (Ulaş), E7 (Eskişehir) and E9 (Altıntaş). On the other hand, E2 (Çumra) was the best representative of the overall environments and the most powerful to discriminate genotypes.
This study was carried out to determine the yield performances of 20 bread wheat genotypes across six environments in Central Anatolia, Turkey, in the 2000-2001 growing season. The experimental ...layout was a randomized complete block design with four replications. Additive main effects and multiplicative interactions analysis (AMMI) indicated that the yield performances of genotypes were under the major environmental effects of genotype by environmental interactions. The first two principal component axes (PCA 1 and 2) were significant (p < 0.01) and cumulatively contributed to 78.64% of the total genotype by environment interaction. A biplot generated using genotypic and environmental scores of the first two AMMI components also showed that genotypes with larger PCA 1 and lower PCA 2 scores gave high yields (stable genotypes), and genotypes with lower PCA 1 and larger PCA 2 scores had low yields (unstable genotypes), as in the sites tested.
The development of genotypes, which can be adapted to a wide range of
environments, is the one of the most important goal of plant breeders in a crop
improvement program. In this study, 6 six ...stability measures consisting of 4 parametric and 2 nonparametric were used to evaluate the genotype by environment interaction (GEI) in 20 durum wheat genotypes. The genotypes were evaluated for grain yield at fourteen environments in the Central Anatolian Region of Turkey for two years. The experimental layout was a randomized complete block design with three replications. Genotypes, environments main effects and GEI were significant at P < 0.01. Both parametric ($b _i, S^2 _ {di} R_i^ 2 , P_{i}$) and nonparametric ($S_i^ {(1)} , S_i^{(2)}$) univariate stability statistics were used to determine stability of the durum wheat genotypes. Genotypes 20, 13 and 12 were most stables based on genotypes according to six stability measures. The level of associations among the stability measures was assessed using Spearman's rank correlation. Regression coefficient $(b_i)$ was negatively and significantly correlated (P < 0.01) with superiority index $(P_i)$. On
the other hand, $S_i^ {(1)} , S_i^{(2)}$ and $S^2 {di}$ were positively and significantly correlated with $P_i$. As a result, these relationships reveal that only one of them could be sufficient to select
genotypes of interest in a durum wheat breeding program.
Bu araştırma, 13 makarnalık buğday (Triticum turgidum var. durum Desf.) genotipinde tane verimi yönünden genotip çevre interaksiyonunu açıklamak ve stabil genotipleri belirlemek amacıyla Orta ...Anadolu'da yağmur koşullarında tesadüf blokları deneme desenine göre 4 tekerrürlü olarak, 3 lokasyonda 2 yıl sure ile yürütülmüştür. Genotip x çevre interaksiyonunun analizinde doğrusal regresyon teknikleri kullanılmış ve tane verimi bakımından genotipler ve çevreler açısından önemli varyasyonlar belirlenmiştir. Genotiplerin tane verimi stabilitesinin belirlenmesinde Eberhart-Russell metodu kullanılmıştır. Stabilite analizi sonucuna göre regresyon katsayısı (b,) 1.0 yakın ve en düşük regresyondan sapma kareler ortalamasından birisine sahip $(s^2_{di})$ olan 10 numaralı genotip en stabil olmuştur. Bu genotipin belirtme katsayısının da 0.98 olması stabil bir genotip olduğunu ayrıca doğrulamıştır. Buna karşılık, 2, 7, 8, 11, 12 ve 13 numaralı genotipler ise 1.0 dan büyük regresyon katsayısı ve ortalamadan yüksek tane verimleri ile çevresel değişikliklere en duyarlı genotipler olarak değerlendirilmiştir. Bu genotipler içerisinde 12 ve 13 tüm çevreler üzerinden en yüksek tane Verimini vermiştir. Bu genotipler aynı zamanda düşük regresyondan sapma kareler toplamına $(s^2_{di})$ sahip olmuşlar ve iyi çevrelere önerilebilen, çevre değişikliklerine olumlu cevap veren genotipler olarak değerlendirilmişlerdir.
The objectives of this research were to assess genotype-environment (GE) interaction and to determine stable durum wheat (Triticum turgidum var. durum Desf.) genotypes for grain yield in the Central Anatolia. Thirteen durum wheat genotypes were evaluated under rainfed conditions using a randomized complete block design with 4 replications. The study was repeated for 2 years and at 3 different locations around Central Anatolia, Turkey. GE interaction was analyzed using linear regression techniques. There was considerable variation for grain yield among both genotypes and environments. Stability was estimated using the Eberhart and Russell method. According to the stability analysis, genotype 10 was the most stable for grain yield. The regression coefficient ( $b_i$ ) for genotype 10 was almost unity ( $b_i$ = 1) and had one of the lowest deviations from regressions (s2di). The coefficient of determination $(R_i^2)$ for genotype 10 was as high as 0.98, confirming its stability. In contrast, genotypes 2, 7, 8, 11, 12 and 13 showed regression coefficients greater than 1.0, indicating sensitivity to environmental changes for grain yield. Among the genotypes, the highest grain yield was obtained from genotypes 12 and 13 (3.49 t $ha^{-1}$ and 3.38 t $ha^{-1}$ ) across environments. These genotypes (12 and 13) had deviations from regression values $(s^2_{di})$ around zero, suggesting that they were responsive to changing environments and could be recommended for favorable environments.
The objectives of this research were to assess genotype environment interaction and determine stable oat (Avena sativa L.) cultivars for grain yield in Central Anatolian Region of Turkey. Stability ...analysis 9 were to performed on results for grain yield of 5 oat cultivars (Chekota, Yesilkoy-1779, Yesilkoy-330, Faikbey-2004, Seydisehir-2004) from 24 trials (6 irrigated, 18 rain fed ) was conducted over 6 years in the Central Anatolian Region, Turkey. There was considerable variation in grain yield within and across environments. Year by location and location variability were dominant sources of interactions. The cultivar, “Seydisehir-2004” with respective regression coefficient value of 1.03, the smallest deviations from regressions (S2di) value and the highest grain yield could be considered the most widely adapted cultivar. The other test cultivars were sensitive to production-limiting factors, their wider adaptability, stability and general performance to the fluctuating growing conditions within and across environments being lowered.
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