پديد آورندگان :
محمدي، رضا سازمان تحقيقات، آموزش و ترويج كشاورزي - موسسه تحقيقات كشاورزي ديم كشور , آرميون، محمد سازمان تحقيقات، آموزش و ترويج كشاورزي - مركز تحقيقات كشاورزي و منابع طبيعي ايلام , صادق زاده، بهزاد سازمان تحقيقات، آموزش و ترويج كشاورزي - موسسه تحقيقات كشاورزي ديم كشور , گلكاري، صابر سازمان تحقيقات، آموزش و ترويج كشاورزي - موسسه تحقيقات كشاورزي ديم كشور , خليل زاده، غلامرضا سازمان تحقيقات، آموزش و ترويج كشاورزي - مركز تحقيقات كشاورزي و منابع طبيعي آذربايجان غربي , احمدي، حسن سازمان تحقيقات، آموزش و ترويج كشاورزي - مركز تحقيقات كشاورزي و منابع طبيعي كردستان , عابدي اصل، غلامرضا سازمان تحقيقات، آموزش و ترويج كشاورزي - مركز تحقيقات كشاورزي و منابع طبيعي اردبيل , اسكندري، مسعود سازمان تحقيقات، آموزش و ترويج كشاورزي - مركز تحقيقات كشاورزي و منابع طبيعي خراسان شمالي
كليدواژه :
گندم دوروم , اثرات متقابل ژنوتيپ x محيط , آماره هاي پايداري , GGE باي پلات , پايداري و استقامت
چكيده لاتين :
Introduction: Durum wheat (Triticum turgidum L. var durum) makes up only 5% of the world`s total cultivated wheat area and contributes about 10 % to the total global wheat production. In recent years, the production level of durum wheat has risen to more than 30 million tons with EU, USA and Canada together representing 60% of the production. Durum wheat in Iran is grown on 300-400 thousand hectares with an average annual production of 500-600 thousand tons. Iran has been cooperating with International Center for Agricultural Research in the Dry Areas (ICARDA) on increasing wheat production since 1992. Increase in yield is one of the primary aims pursued in plant breeding programs (Reynolds et al., 2009). This can be achieved through increasing yields under mild stress conditions or improving yield stability (Blum, 2005). Similar to other crops, insufficient yield stability in durum wheat is recognized as a one of the factors responsible for the gap between actual yield and potential yield, particularly in the stressful environments (Cattivelli et al., 2008). In breeding programs, the identification of superior genotypes is difficult due to environmental variability of target locations and the interaction of these variabilities with the investigated genotypes. Therefore, it is important to evaluate the advanced agronomic lines across various environments and over multiple years to ensure their yield stability and production (Yan and Rajcan, 2002). A genotype typically gives differential yield responses 2016in different environments so that its ranking varies across various environments. These yield variabilities, which stem from the interaction between genotype (G) and environment (E), are known as genotype x environment interaction (GE) (Al-lard and Bradshaw, 1964). Many statistical models have been suggested to analyze GxE interaction. GGE (genotype plus genotype-by-environment) biplot method proposed by Yan et al. (2000) is a multivariate model, which is based on principal component analysis, that simultaneously represents G, E and GxE interaction on a graph known as biplot. GGE biplot is widely used in agricultural research as it provides a simple graphical interpretation of GxE interaction. The aim of the study was to evaluate grain yield stability and adaptability in some improved durum wheat lines relative to the check cultivars grown under rainfed conditions by farm-ers in the cold, mild cold and moderate warm regions of Iran. Materials and Methods :Twenty one improved durum wheat lines (G1-G21) along with newly released durum wheat cultivar Saji (G22), two local durum wheat cultivars Zardak (G23) and Gardish (G24) as well as one local bread wheat cultivar Sardari were investigated for three cropping seasons (2011-2013) at seven Agri-cultural Research Stations (Maragheh, Qamloo, Shirvan, Uromieh and Ardebil with a cold climate, Sararood with a mild cold climate and Ilam with a moder-ate warm climate) under rainfed and complementary irrigation conditions. The experimental design at all locations was a randomized complete block with three replicas. Some agronomic attributes such as the number of days until anthesis, pant height, the number of days till physiological maturity, 1000-kernel weight and grain yield were determined for each genotype. However, only the grain yield data was used to analyze GxE interactions. Combined analysis of variance for grain yield was performed using GenStat (ver.12) software. For the combined analysis, the environments (location–year combination) were considered as random effects and the genotypes were regarded as fixed effects. Hence, the analysis of variance was carried out based on a mixed-design model. The GGE biplot methodology was employed to analyze GxE interaction (Yan, 2001). To determine probable mega environments, the which-won-where pattern of the GGE biplot was used in the durum wheat breeding program. Also the GGE biplot model was used for the following purposes; (i). evaluation of yield stability, (ii). the simultaneous selec-tion for yield and stability, (iii). identification of ideal durum wheat genotypes, (iv). assessment of the characteristics of and relationships among the testing envi-ronments.Results and discussion: The combined analysis of variance showed significant differences among the main effects due to E and G and G × E interaction. The sum of squares of GE interaction was 15 times larger than that of the genotypes, suggesting the possible existence of mega-environmental groups for the genotypes. Grouping of the environments was not repeatable among the years. Many of the wheat durum breeding lines exhibited a high combination of yield and stability across both drought and cold environments, comparable to check cultivars. The evaluation of genotypes based on phenotypic stability statistics showed that the breeding lines G8, G2, G7 and G11 and the cultivar Saji outperformed the other genotypes in terms of the best combination of high yield and good stability. Graphic analysis of GE interaction using the GGE biplot model indicated that the cold environments of Maragheh, Ardebil, Qamloo, Shirvan and Uromia differed from the mild cold and moderate warm environments of Kermanshah and Ilamin in identifying specific adapted genotypes. The wheat breeding lines, which gave higher yields and had a greater average 1000-kernel weight and plant height as well as maturity earliness, were found to be more adapted to the moderate environments rather than the cold environments. Because of the lower mean yield in the colder environments, there was clear discrimination between cold-tolerant (old varieties i.e., Zardak and Sardari) and cold-susceptible (i.e., breeding lines) genotypes. Clear discrimination was possible for drought because the trials were conducted under both rainfed and irrigated conditions. Positive increase in yield and yield stability of the breeding lines compared to the check cultivars indicated genetic improvement for both high yield and stability performance in the durum wheat breeding program. Based on GGE biplot analysis, the locations with high repeatability were Shirvan with high representativeness, Qamloo with average representativeness and Ilam with zero representativeness. Locations with low repeatability included Kermanshah and Uromieh with average representativeness and Ardabil and Maragheh with negative representativeness. These results verified high GE interaction in some locations (i.e. Ardabil and Maragheh ) compared to others (i.e., Shirvan, Qamloo and Ilam). Conclusion: The current durum wheat selection program may lead to yield stability and specific adaptation. This will provide opportunities for genetic improvement of both drought and cold tolerance characteristic in durum wheat.
