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The Amin wheat cultivar, with the pedigree "KAUZ/LUCO-M//PVN/STAR/3/ Yaco/2*Parus/4/Pishtaz", was developed through a national irrigated bread wheat breeding program for the temperate climate of Iran. Initial and advanced crosses were conducted at the Seed and Plant Improvement Institute in Karaj, Iran, while the evaluation and selection of segregating generations (F2-F6) carried out at the Zarghan Research Station in Fars Province. Selected lines, including M-94-14, advanced to both preliminary and advanced yield trials. Under optimal irrigation conditions in temperate climate adaptation trials, the M-94-14 line (Amin cultivar) achieved an average grain yield of 6950 kgha-1, representing a 3.9% and 5.7% yield advantage over the control cultivars Parsi and Baharan, which yielded 6688 and 6574 kgha-1, respectively. This line exhibited desirable baking quality traits, including favorable grain protein content, Zeleny sedimentation volume, bread loaf volume, grain hardness index, and SDS sedimentation height. Additionally, it demonstrated acceptable resistance to yellow and leaf rusts. On-farm trials across various regions showed that the Amin cultivar achieved a grain yield of 6820 kgha-1 under optimal irrigation conditions, outperforming the average grain yield of control cultivars, which was 6609 kgha-1. Given the superior performance of this line compared to existing cultivars in temperate climate of Iran, the M-94-14 line was officially released as the Amin cultivar in 2019.

In crop season 2012-2013 wheat genotype "Frncln/Rolf07" was introduced to Iran within an international nursery received from CIMMYT and was studied in experiment of evaluation of yield and agronomic characteristics of spring wheat genotypes in international nurseries in temperate regions. Then in 2013-2014 crop season, it was selected in a preliminary regional wheat yield trial under normal irrigation with an average yield of 8114 kgha-1 compared to the check cultivars Parsi, Sirvan, Pishtaz and sivand, respectively, with grain yield of 8.035, 8.022, 6.914 and 7.985 kgha-1. This cultivar was further investigated in the advanced regional wheat yield trial of temperate regions of the country during 2014-2015 and with average grain yield of 7093 kgha-1 compared to 6495 and 6423 kgha-1 yield of check cultivars Parsi and Sirvan, respectively, and was selected for adaptation evaluation. The average yield of M-94-15 line in temperate climate adaptation experiment during the 2015-2017 crop season under normal conditions was 7231 kgha-1 verses 6688 kgha-1 of Parsi cultivar and 6574 kgha-1 of Baharan cultivar and in general, total mean grain yield was 3% higher than the average of whole genotypes. Due to the good condition of M-94-15 line reaction to stripe rust (O-30MR) and leaf rust (O-30MSS) diseases, as well as the resistance to grain shattering and good bread making quality, this line was selected for study at the level of farmers' fields. Wheat line M-94-15 based on its favorable agronomic characteristics, suitable earliness and good bread making quality was released in 2019 as Farin for cultivation in temperate agro-climatic regions.

IntroductionProduction of high-yielding and stable cultivars is the most important objective of crop breeding programs, including wheat. The final yield of each plant is determined by the potential of genotype (G), the effect of environment (E) and the interaction effect of genotype × environment (GE). Several methods have been presented to study the genotype × environment interaction and determine stable genotypes, which can totally be divided into two main categories, univariate and multivariate. Univariate methods do not provide a complete view of the complex and multidimensional nature of GE interaction, therefore, the use of multivariate methods is suggested to solve this problem. Among the multivariate methods, AMMI and GGE-Biplot methods are more important. The objective of the current experiment was to investigate the interaction between genotype and environment for grain yield of 20 wheat genotypes and to identify stable and high-yielding genotypes.Materials and methods The plant materials of this experiment were 20 wheat genotypes including 18 irrigated wheat lines along with two control cultivars, Rakhshan and Baharan. The experiment was carried out in a randomized complete block design with three replications in five temperate regions (Karaj, Kermanshah, Zarghan, Boroujerd and Mashhad stations) during two cropping years 2019-2020. Two multivariate methods, AMMI and GGE-Biplot, were used to investigate the interaction effect of genotype × environment and to evaluate the stability of genotypes. R software was used to analyze the experimental data using the AMMI method, and Genstat software was used to analyze the data using the GGE biplot graphic method.Research findingsThe results of combined analysis of variance showed that the interaction effect of genotype × year and genotype × year × location were significant at the 1% probability level. Based on the results of AMMI analysis, the effect of environment, genotype and genotype × environment interaction were significant. Based on AMMI1 and AMMI2 models, AMMI stability value (ASV) parameter and genotype stability index (GSI), genotype 12 with an avearage grain yield of 8.27 tons per hectare was determined as the best genotype. The study of GGE-biplot polygon led to the identification of three mega-environments, that Boroujerd had the highest power of representation and differentiation among different environments. Genotypes 12 and 9, in addition to having high yield, had higher yield stability. Genotypes 12 and 9 were placed in the center of the circle as the ideal genotype and genotypes 5, 7 and 18 were ranked next. Based on the results of both methods, genotype 12 was identified as the most stable genotype.ConclusionThe results of AMMI, AMMI stability index (ASV) and genotype stability index (GSI) compared to GGE biplot results showed that all these indices have a good potential to evaluate the performance stability of genotypes. Nevertheless, GGE biplot results are more effective and practical in examining the compatibility and stability of genotypes' performance in different environments due to the ease of interpreting graphical results.

A bread wheat breeding line that led to release of Tallaei cultivar introduced from International Research Center for Maize and Wheat (CIMMYT) to Iran through an international nursery in 2009 and was evaluated in a primary trial in Islam Abad-Gharb research station and due to its favorable characteristics was selected for further evaluation. This line showed grain yield of 6967 and 5370 kgha-1 under normal irrigation and terminal drought conditions, respectively, while mean grain yields of four check cultivars: Parsi, Sivand, Bahar and Pishtaz for those two conditions were 6857 and 3850 kgha-1, respectively, Aforementioned line showed grain yield of 4851 kgha-1 in advanced yield trial of temperate regions breeding program under water deficit conditions compared to 4631 khha-1 of drought tolerant check cultivar "Sirvan" in three locations, hence selected for final evaluation in adaptation trial. Grain yield of this line which was presented as M-91-18 at the adaptation trial was 7563 and 6385 kgha-1 against 8022 and 6200 kgha-1 of Parsi check cultivar under normal and water stress conditions, respectively, during two cropping seasons 2012-13 and 2013-14. This line showed overall mean grain yield, of 9583 and 8042 kgha-1 in normal irrigation and water deficit conditions under extensional farmer fields, respectively. For these two conditions check cultivar Parsi showed 7875 and 6828 kgha-1 records. Grain yield potential of this line was recorded as 10070 and 10670 kgha-1 in Alborz and Kermanshah farmers' fields, respectively. According to the latest evaluations the response of this line to yellow and leaf rusts was moderately resistant under severe artificial infection. Wheat line M-91-18 has considerable earliness and good bread making quality and based on its good agronomic characteristics in 2017 this line was released as Tallaei, for cultivation under normal and terminal moisture stress conditions in temperate agro-climatic regions.

This study was conducted with the objective of analyzing genotype × environment (GE) interaction on grain yield of 20 bread wheat promising lines. The experiment carried out using randomized complete blocks design with three replications in eight experimental stations in temperate regions of Iran in two cropping seasons (2015-2017). To assess the yield stability and adaptability of genotypes non-parametric ranking statistic and some univariate stability statistics as well as GGE biplot method were used. Combined analysis of variance revealed that genotype × year × location and year × location interaction effects on grain yield were significant. Mean comparison showed that promising lines; G16, G12, G10 and G15 had the highest grain yield, respectively. Nonparametric ranking analysis showed that genotypes; G4, G12, G14, G15 and G16 with the lowest ranks and standard deviation of ranks had the highest yield stability. The GGE biplot analysis differentiated environments into three sub-environmental groups with top-yielding genotypes. Using GGE biplot showed that genotypes; G2, G3, G13, G14, G18, G4 and G1 had higher grain yield stability, respectively. Based on non-parametric ranking statistic and GGE biplot, genotype G14 was identified as genotype with highest yield stability. According to the results of this tsudy genotypes G14: KAUZ/LUCO-M//PVN/STAR/3/Yaco/2*Parus/4/Pishtaz (Amin), G15: FRNCLN/ROLF07 (Farin), and G16: MUU/KBIRD had high grain yield potential and stability performance and have been recommended for release as new cultivars for the temperate agro-climatic zone of Iran.

Torabi wheat cultivar introduced to iranian wheat breeding program through an international nursery from CIMMIT (28th SAWSN) in 2010 and was evaluated under terminal drought stress implemented from the flowering stage in 2010-2011 cropping season. Then in 2011-2012 cropping season it was tested in the preliminary regional wheat yield trial under terminal drought stress in Karaj and was selected based on its average grain yield of (4878 kgha-1) compared to the average grain yield of (3939 kgha-1) Parsi check cultivar. This cultivar was further studied in the advanced regional wheat yield trial in the temperate regions of the country during 2012-2013 and with average grain yield of 6634 kgha-1 under drought stress condition compared to 6073 and 6768 kgha-1 yields of check cultivars Parsi and Sirvan, respectively, was selected for evaluation in the adaptability and yield stability. The average grain yield of Torabi (line M-92-20) in adaptability experiment during the years 2013-2015 under drought stress conditions was 6516 kgha-1 compared to 6110 kgha-1 of Sirvan check cultivar and 5697 kgha-1 of Parsi check cultivar and also its total grain yield mean was 3% higher than the average grain yields of all genotypes. Due to the resistant reaction of the line M-92-20 to stripe and leaf rust diseases, as well as the early maturity and very good bread making quality, this line was selected for evaluation in the on-farm trials in farmer’s fields. Overall in farmer’s fields, this line had grain yield mean of 8637 kgha-1 under normal irrigation, and 5672 kgha-1 under water deficit conditions compared to the average yield of check cultivars with 6150 kgha-1 under optimal conditions and 5104 kgha-1 under water deficit conditions.

Salinity stress is one of the major problems for crop production. Barley is one of the best salt tolerant plants and is widely cultivated in the saline soils, but all stages of its growth as well as its grain yield are affected by salt stress. Golshan  was resulted from the cross between Nik cultivar as female parent and an Iranian landrace with 1-BC-80320 collection code, as male parent. Crossing and selection processes of this variety were carried out in experimental farm of Seed and Plant Improvement Institute (SPII), Karaj, Iran. Yield trials were performed under salinity stress in Yazd, Isfahan and Birjand research stations (EC of soil and water: 10-14 dsm-1). The result showed that Golshan with grain yield of 4392 kgha-1 had 17% higher yield performance compared to check cultivar Khatam with grain yield of 3752 kgha-1. Evaluation of salt tolerance related traits such as chlorophyll content, plant height, number of yellow leaves, root length, root weight, shoots to root ratio, biomass and potassium to sodium ratio under hydroponic controlled condition showed that Golshan had high tolerance to salinity stress. This new variety has spring growth habit and its average plant height under salinity condition was 65 cm. Golshan has semi-susceptible to susceptible reaction to the barley leaf diseases. Golshan has six-rowed spike with average of 12.3% protein content and is recommended for cultivation in the saline areas in the temperate regions of the country.

To date, wheat counts as one of the most important cereal grains, feeding the increasing world population (Feldmann, 2001). Evaluation of the genetic diversity of wheat genotypes will provide a great opportunity to improve its yield quality and increase its grain output. The results of previous studies on wheat have shown correlations among grain yield and its components such as number of tillers, spike length, grain number per spike, thousand-kernel weight and harvest index. However, because of complex relations among different traits and their interactions with grain yield of wheat, simple correlations of these traits can not be directly and unequivocally used to clarify those relationships. Therefore, different statistical techniques can be employed in modeling the crop yield, including correlation, regression, path analysis, factor analysis, factor components, and cluster analysis (Leilah & Al-Khateeb 2005). The goal of this study was to identify variability in grain yield and some agronomic and morphological traits and their relationship among 150 doubled haploid wheat lines. Materials and Methods In this study, morphological and phenotypic traits of 150 doubled haploid wheat lines derived from three different crosses: 1) DH-26: Ghods*3/MV17, 2) DH-27: Flanders/3*Ghods, 3) DH-28: Hybrid Bersee/*3Ghods, which consisted of 75, 45 and 30 individuals, respectively, were evaluated. The experiment was conducted using an augmented design with six check cultivars including Parsi, Mihan, Bolani, Ghods, Hybrid Bersee and MV17, which were repeated over five blocks. Some agronomic traits such as days to %50 of flowering, days to maturity, spike length, number of spikelets per spike, number of grains per spike, grain weight per spike, thousand kernel weight, plant height, grain density per spike and grain yield of DH lines as well as check cultivars were evaluated. DH lines were classified with hierarchical cluster analysis using Ward method as well as using multivariate statistical methods such as factor analysis, stepwise regression and path analysis. Statistical procedures were carried out using SAS 9.0 and SPSS 16 software packages. Results and Conclusion The analysis of variance showed that there were significant differences for days to %50 of flowering, days to maturity, spike length, number of spikelets per spike, number of grains per spike, grain weight per spike, thousand kernel weight, plant height, grain density per spike and grain yield. The determination of coefficients of variations for phenotypic and physiological traits of all three DH populations indicated that most of the studied traits had a high genetic variability. Evaluation of grain yield among different population showed that DH-26 population with an average grain yield of 4.885 T/ha had higher grain yield compared to other two populations, although within each population several lines with higher yields and superior agronomic and morphological traits than their parents and control cultivars were identified. The coefficients of correlations among yield components showed that grain yield had a positive and significant correlation with grain weight per spike and thousand-kernel weight while its correlation with days to 50% of flowering, days to maturity and number of spikelets per spike was negative and significant. The results of factor analysis indicated that three major factors effective on earliness, spike and plant height explained %68.47 of the total variation. The results of stepwise regression analysis showed that thousands kernel weight had the most important effect on grain yield and explained 8.8% of the variation. The path analysis of data indicated that, number of spikelets per spike and thousand-kernel weight had the highest direct effects on grain yield. The current genetic variability of DH lines, which are derived from parents with good agronomic traits, especially yellow rust resistance (Bakhtiar et al., 2015), can be employed for the selection of the superior genotypes that possess all beneficial characteristics. 

In this study, adaptability and grain yield stability of 18 bread wheat promising lines and two commercial cultivars (Parsi and Baharan) were evaluated using randomized complete blocks design with three replications in 2015-17 cropping seasons in eight experimental stations; Karaj, Kermanshah, Zarghan, Broujerd and Mashhad (under normal irrigation), Neishabour, Isfahan and Varamin (cessation of irrigation at the 50% heading stage), Iran. Combined analysis of variance showed significant genotype × year × location and year × location interaction effects on grain yield. Due to the significant effects of these interactions, the grain yield stability of genotypes as well as genotypes × environments interaction effects were evaluated using non-parametric ranking statistic and AMMI multivariate stability analysis. Mean comparison of grain yield showed that promising lines 16, 12, 10 and 15 had the highest grain yield, respectively. Non-parametric ranking analysis showed that promising lines; 4, 12, 14, 15 and 16 with the lowest ranks and standard deviation of ranks had the highest grain yield stability, respectively. By using biplot graphic of the first two components of AMMI, genotypes 2, 4, 13 and 14 were identified as genotypes with high yield stability, respectively, which also had the least AMMI stability values. Considering grain yield and other agronomic characteristics, promising lines; 14, 15 and 16 that had high grain yield and yield stability and were selected for being released as new commercial cultivars in temperate regions of Iran.

Variation and selection play a key role in breeding programs. The proper selection is related to the desired variation in the desired trait. In order to take advantage of the existing variation; the evaluation of germplasm resources is necessary. Genotype–environment interactions are particularly important for breeders and one of the complex issues in breeding programs is the selection of high yielding and stable crop genotypes. Therefore, knowledge of the genotype–environment interactions is a necessity to evaluate new cultivars in different environments. GGE biplot model is one of the most used multivariate methods in the study of genotype–environment interactions that is performed based on principal component analysis (Yan et al., 2010).

In order to select the superior lines from the elite spring bread wheat yield trial (17ESBWYT), 50 spring bread wheat lines (considering Parsi culivar as a local check) were studied at three stations (Karaj, Kermanshah and Zarghan), which represent moderate climate regions of Iran. The experiments were conducted in the randomized complete block design (RCBD) with three replications in the 2016- 2017 growing season. The plant materials had been received from the international center for agricultural research in the dry areas (ICARDA). The measured traits included days to heading (DHE), days to maturity (DMA), plant height (PLH), thousand grain weight (TKW), seed filling period (SFP), seed filling rate (SFR), grain yield (GY), relative yield to mean (RYM), relative yield to local check (RYLC) and plant response to yellow rust (YR) and leaf rust (LR). Homogeneity of the variances in different environments was tested following Bartlett's test. Then, the combined analysis of variance and stability analysis were performed using GGE biplot method. Data was analyzed using GGE biplot4, heatmapper, SAS and Excel.

The combined analysis of variance confirmed that the effects of environment, genotype and interaction between them were statistically significant. Mean comparison of grain yield showed that the highest grain yield (6.489-ton ha-1 ) was achieved with the genotype no 32 and the lowest grain yield (4.728-ton ha-1) was related to the genotype no 25. Total mean of grain yield at stations of Karaj, Kermanshah and Zarghan was 6.589, 5.317 and 4.753-ton ha-1 respectively. The correlation biplot of the environments revealed that the location of Kermanshah had a positive correlation with Karaj and Zarghan, because the angles of the vectors were less than 90◦, exhibiting a positive correlation among the environments. Also, there was a weak correlation between Karaj and Zarghan, indicating that two environments have been almost independent of each other because the angle of the vectors was 90◦ (Yan & Rajcan, 2002). The yield and stability of the genotypes were evaluated using the average-environment coordination (AEC) view. Presence of genotypes on this axis is approximation of grain yield (Yan et al., 2000). Hence, the genotypes no 32, 18, 24, 28, 31, 14, 33, 19, 29 and 2 had the highest grain yield. The vertical axis of AEC biplot also showed the interaction between genotype and environment and determined the stability of the genotypes. Therefore, among the genotypes that gave a high grain yield, the genotypes no 32, 18, 24, 14, 29 and 2 were the most stable for grain yield. The final selection of the genotypes was carried out considering the response of genotypes to yellow rust and leaf rust and other desirable traits.

In the current study, 50 genotypes of bread wheat were evaluated in terms of grain yield, response to yellow rust and leaf rust and some desirable agronomic traits at three stations (Karaj, Kermanshah and Zarghan) representing moderate climate regions of Iran. Considering the results of GGE biplot method and response to yellow rust, leaf rust and other desirable agronomic traits, eight genotypes: no 32, 24, 28, 14, 33, 19, 29, and 2 were selected as superior lines and were conducted to preliminary regional wheat yield trial (PRYWT) in the moderate climate regions of Iran. It is hoped that in the coming years a new cultivar will be released among the selected genotypes in wheat breeding programs in moderate climate regions of Iran, after preliminary and adaptation experiments.

Drought Stress is one of the most important and common environmental stresses that restricts agricultural production and reduces production efficiency in semi-arid and dryland areas (Sarmadnia, 1993). Information on yield stability of genotypes under both favorable and drought stress conditions is essential to identify drought-tolerant genotypes by plant breeders and genotypes with good performance in both environments are preferred (Uddin et al., 1992). In International Maize and Wheat Improvement Center (CIMMIT), the F3 and F4 generations are selected under limited irrigation conditions. The selected plant materials in the fifth and sixth generations are evaluated under normal conditions, and in seventh and eighth generations performance comparison and other evaluations are studied under water stress and natural conditions. This method of evaluation and selection under stress and non-stress conditions has been suggested and applied by many researchers on wheat and other crops (Ehdaie et al., 1988). The goal of this study was selection of drought tolerant bread wheat lines based on their tolerance indices and pedigree analysis.

In this experiment, 291 lines and cultivars of bread wheat along with four check cultivars including Parsi, Pishtaz, Sirvan, and Sivand were evaluated to identify tolerant genotypes for terminal drought using two identical experiments, one under non-stress condition and the other one under drought stress condition (irrigation cut-off after 50% of anthesis). Experiments were conducted using the observational method without replication. During the developmental stages, the traits including green percentage, days to heading, days to maturity, plant height, grain color, thousand-grain weight, lodging percentage, shattering and grain yield per plot were recorded. Drought susceptibility and tolerance indices such as STI, SSI, GMP, MP and TOL were calculated for all the investigated entries based on 1000-grain weight and grain yield. In order to investigate the genetic background of selected lines, the percentage of genetic contributions of each genotype was calculated based on the pedigree of the lines.

The results indicated that under both stress and non-stress conditions, the selected lines were relatively early mature. Comparison of arithmetic means (MP), geometric mean (GMP) and drought tolerance index (STI) of the genotypes revealed that selection based on these criteria leads to the selection of high yield genotypes under both stress and non-stress conditions. In terms of grain yield, genotypes 33, 2, 34, 23, 10 and 11 had the lowest SSI, which was associated with a higher yield of these lines under drought stress. Also, in terms of 1000-grain weight, genotypes 10, 11, 32, 33, 34, 8 and 5 had the lowest SSI indices where this trait was significantly correlated with high seed weight under drought stress. Lines 11, 14 and 34 had the highest STI index for grain yield and 1000-grain weight, which was significantly associated with high grain yield and 1000-grain weight under normal conditions. Finally, 34 superior drought tolerant lines were selected in two stages according to STI and SSI indices. Pedigree analysis of the selected lines showed that genotypes PASTOR, WBLL1, SKAUZ, and Y50E had contributions of 11.21%, 6.34%, 4.04%, and 4.04% in germplasm composition under drought condition, respectively, indicating their impact on drought tolerance. On the other hand, genotypes CHIBA, KACHU and 1-73-240 had 0.01%, 0.02%, and 0.02% contribution in germplasm composition under drought conditions, respectively, showing no influence in drought tolerance.

The results of this study showed that the genetic structure of some Iranian wheat cultivars such as Omid, Pishtaz, Parsi, Marvdasht, Alborz and Atrak, respectively, made contributions of 2.78%, 2.39%, 1.47%, 1.47% and 1.44% to the genome of the selected lines. Finally, it was suggested that, in addition to the above-mentioned Iranian cultivars, breeding lines derived from genotypes such as PASTOR, KAUZ, SKAUZ, WBLL1, PBW343, Y50E and MUNAL #1 can be used in breeding programs to produce suitable germplasm with early maturity and tolerance to terminal-drought stress for temperate climate of Iran.