Realized gains from selection for spring wheat grain yield are different in conventional and organically managed systems

Breeding spring wheat (Triticum aestivum L.) specifically for organic production has been suggested by producers and researchers alike. To investigate the effects of management systems on selected spring wheat breeding line performance in multi-location tests in the northern Great Plains, we used a randomly derived population of 79 F6-derived recombinant inbred lines (RILs) from a cross between the Canadian hard red spring wheat cultivar AC Barrie and the CIMMYT derived cultivar Attila. The population, including the parents, was grown on conventionally and organically managed land in 12 environments over 3 years. Direct selection in each management system (10% selection intensity based on grain yield) resulted in three lines being retained in each management system, over the multi-location testing. Gains from 10% selection for grain yield in a ‘selection’ year were 3.4 times greater in conventional multi-site yield trials than in organically managed trials. Two lines (BA 05 and BA 36) ranked in the top 10% of both the conventional and organic selection trial of 2005, remained ranked 2nd and 1st, respectively, under conventional management in multi-site yield trials. However, these lines ranked 53rd and 21st, respectively, for grain yield in the multi-site organic yield trials. Selected lines were each yield stable within the management system in which they were selected. Following replicated multi-location yield trials, three lines from the population (BA 02, 29 and 58) ranked within the highest 10% yielding lines in both conventional and organic systems. The results of this study suggest that selection differences occur across multi-location tests, and that selection for grain yield in organic systems should be conducted within organic systems. It is evident, however, that data obtained from conventional yield trials also has some relevance towards breeding for organic environments.     

Effekte der Sorten- (Weizen)und der Arten- (Weizen, Roggen) Mischung auf die Ertragsleistung krankheitsfreier Bestände

Effects of cultivar (wheat) and species (wheat, rye) mixtures on grain yield of desease-free stands
Cultivar mixtures (winter wheat) and species mixtures (winter wheat/winter rye) grown free from pests and diseases in different environments are compared to pure stands and analyzed with respect to inter-component relationships relevant for yield. All mixtures consisted from two components which were planted 1:1. Mixing effects (i.e. deviations from arithmetic mean of respective components grown in pure stands) on grain yield/ha and yield structure were dependent on components and growing conditions, particularly nitrogen availability. Under conditions suboptimal for one component, ontogenetic differences between components resulted in positive mixing effects on grain yield since the yield proportion of the accompanying partner increased more than proportionally. In several instances, yield proportions shitted without leading to mixing effects. In some experiments and/or mixtures mixing effects could not be observed at all.     

Reciprocal performance of winter wheat in Hungary and Oklahoma, USA

International wheat ( Triticum aestivum L.) performance trials have revealed adaptive responses in vernalization and photoperiod for certain Eastern European cultivars when field-tested in Oklahoma in south central USA. Common experiments were conducted in Hungary and Oklahoma with 12 elite germplasm varieties or lines from each locale to uniformly and directly compare the agronomic potential of hard red winter (HRW) North American wheat and Hungarian bread wheat and to identify potential benefits or hazards for introducing germplasm into reciprocal breeding programmes. Results from four Oklahoma and six Hungarian environments showed that non-native cultivars were 14% and 25% lower in grain yield than native ones in Hungary and Oklahoma, respectively, although one HRW cultivar (2163) exhibited exceptional yield potential in both locations. The lower grain yield potential of Hungarian genotypes in Oklahoma was reflected primarily in lower spike production at harvest. Yield performance in one location did not correlate with performance in the other. Greater consistency between locales was found for test weight (r = 0.6, P < 0.05) and heading date (r = 0.9, P < 0.01); thus, screening for those traits prior to introduction of parent material may be useful. Although some recovery of the genetic yield potential of native material will be necessary, intergroup crossing between these apparently distinct gene pools should provide a new and valuable resource for bread wheat cultivar development.     

Analysis of adaptation of barley,triticale, durum and bread wheat under Mediterranean conditions

Summary Yield data obtained from a comparative small grain cereals trial, grown for five consecutive growing seasons at a total of 23 environments in Cyprus, were subjected to regression analysis. Within each environment, yield trials consisted of a standard set of three cultivars or elite lines of barley, triticale, durum and bread wheat. The regression coefficient (b) of crop mean on the environmental index (I) and the mean square deviation from regression (sd²) were calculated for each crop. Each crop tended to have its own characteristic value of sd² and its magnitude was an excellent indicator of specific crop-environment interaction. The causes of large sd², for two of the four crops, were the susceptibilith of barley to lodging, when favourable conditions were encountered at high yielding environments, and triticale dependence on late season precipitation. Durum wheat and triticale had an average response to different yielding environments (b>1.19) and both were significantly different from those of bread wheat (1.08) and barley (0.54). Hence, barley, bread and durum wheat are specifically adapted to low, average and high yielding Mediterranean environments, respectively. The cultivation of triticale at the expence of durum wheat is not feasible. Furthermore, interactions between crops and environments demonstrated by the regression parameters, should constitute the basis for decision making, regarding crop adaptation in a region. The average yield in all environments should not be considered as a proper criterion for adaptation. In this study, triticale had a similar mean grain yield (3,842 kg/ha) to that of bread wheat, but was significantly higher yielding than barley or durum wheat (5 and 7%, respectively).     

Genetic improvement trends in agronomic performances and end-use quality characteristics among hard red winter wheat cultivars in Nebraska

Evaluation of wheat cultivars from different eras allows breeders to determine changes in agronomic and end-use quality characteristics associated with grain yield and end-use quality improvement over time. The objective of this research was to examine the trends in agronomic and end-use quality characteristics of hard red winter wheat cultivars grown in Nebraska. Thirty historically important and popular hard red winter wheat cultivars introduced or released between 1874 and 2000 were evaluated at Lincoln, Mead and North Platte, Nebraska in 2002 and 2003. An alpha lattice design with 15 incomplete blocks of two plots and three replications was used at all locations. Agronomic (days to flowering, plant height, spike length, culm length, grain yield and yield components, and grain volume weight) and end-use quality (flour yield, SDS-sedimentation value, flour protein content, and mixograph time and tolerance) traits were measured in each environment. Highly significant differences were observed among environments, genotypes and their interactions for most agronomic and end-use quality characteristics. Unlike modern cultivars, older cultivars were low yielding, and less responsive to favorable environments for grain yield and yield components. Semidwarf cultivars were more stable for plant height than traditional medium to tall cultivars. All cultivars had high grain volume weight since it is part of the grading system and highly selected for in cultivar release. Modern cultivars were less stable than older cultivars for SDS-sedimentation and mixing tolerance. However, the stability of older cultivars was attributed to their having weak mixing tolerance and reduced SDS-sedimentation values. The reduced protein content of modern cultivars was offset by increased functionality, as measured by mixograph and SDS sedimentation. In conclusion, breeders have tailored agronomic and end-use quality traits essential for hard red winter wheat production and marketing in Nebraska.     

Wild wheat adaptation in different soil ecosystems as expressed in the mineral concentration of the seeds

Wild emmer wheat, Triticum dicoccoides, grows naturally in several habitats in northern Israel. The assumption that a genotype is better adapted to the `native' soil from which it was collected than to other soils, was tested. Each of nine T. dicoccoides accessions from nine different habitats and three wheat cultivars was sown in soils taken from all habitats, and grown in a greenhouse over 3 years. To enhance the biological nutrition absorption forces from the soil, three common wheat cultivars were added to the wild genotypes. No interaction in grain yield between wild wheat genotype and soil type was found within experiments. Soil type was the main factor that affected development and yield. Seed nutrient ability (SNA) of each soil was defined as the mineral element content in the seeds, averaged over all genotypes. Multiple regression analysis revealed diversity between the SNA related to growth and yield of the genotypes. Total seed yield per plant of each accession was related to several SNAs, and mainly to S and K, R² = 0.5–0.85. The spikelet number per spike was determined by N and Na in five accessions and by Ca in the other four (R² = 0.39–0.93).Heading date was affected mainly by the genotype, and the soil effect exhibited Fe and P dependence. A genotype-habitat adaptation exhibited by yield components was related to yield quality rather than to yield quantity. When a mineral nutrient is deficient in a natural soil, natural selection leads to establishment of plants that store a higher concentration of that nutrient in the seed, for the benefit of the succeeding generation. This revised version was published online in July 2006 with corrections to the Cover Date.     

Factors influencing the development of bread wheat plant types to be grown in the ‘transitional zone’ in northern Syria

Summary This study sought to identify factors that influence wheat development in the transitional wheat growing zone of northern Syria. Three development factors were studied, intrinsic earliness, and responses to vernalization and to photoperiod. Two sets of wheat were studied, each composed of lines with differing combinations of development factors. Set 1 comprised 20 parental and breeding lines utilized by the CIMMYT/ICARDA facultative and winter wheat breeding program based at Tel Hadya. Set 2 comprised 19 parental and breeding lines utilized by an Australian winter wheat breeding program based at Temora. Field development was recorded in greatest detail at one site. Tel Hadya, using the state of differentiation of the apex of the main tiller of sampled plants. To extend findings, development was also recorded as the time from sowing to ear emergence for later sowings of wheat at Tel Hadya, and in sowings at four other regional sites.The significance of each development factor was tested in multiple regressions that predicted either stage of apical development at Tel Hadya, or time to ear emergence in all trials. It was found that intrinsic earliness was the major factor associated with development, in both sets of wheat. Response to photoperiod had a much smaller and less consistent effect. Response to vernalization had least effect on development, possibly because low temperature in winter delayed development for a longer period than was required to fully vernalize winter wheats. Our results suggested it may not be directly relevant whether spring or winter wheats are grown in the transitional zone of northern Syria. The desired phenotype for the region, of slow development prior to double ridge, then fast development to ear emergence, cannot be simply achieved from combinations of the three development factors. Selection for improved adaptation to the region must continue to rely on direct field observations.     

Recurrent selection for broad adaptation affects stability of oat

A recurrent selection program for adaptation to diverse environments was successful in improving mean oat (Avena sativa L.) grain yield within and across testing environments. The objectives of this research were to determine if this selection program also resulted in changes in other agronomic traits or altered yield stability. Additionally, we investigated how selection modified the response of genotypes to climatic conditions. We evaluated random samples of 100 families from the original population and each of three selection cycle populations in replicated yield trials in Idaho, Iowa, and Norway for two years. Yield stability was assessed via joint regression analysis and superiority analysis. For each cycle, genetic relationships among yields observed indifferent environments were assessed by estimating phenotypic correlations between pairs of target environments. The effect of climate variables on genotype-by-environment interaction (GEI) responses was determined with partial least squares regression. Selection resulted in a small increase in mean heading date, a decrease in mean test weight, and no change in total above-ground biomass or plant height. Genotypic regression coefficients on environmental indices and deviations from regression were larger in the last cycle population, but superiority analysis demonstrated that selection significantly improved the adaptability of the population to the target testing environments. Improved adaptation was also demonstrated by increased phenotypic correlations among the most divergent pairs of environments in the later cycles. Partial least squares regression of GEI effects on climate variables suggested that later cycle families tended to respond more favorably to cooler than average conditions than the original population. Selection resulted in improved yield stability as well as improved mean yield. This revised version was published online in August 2006 with corrections to the Cover Date.     

Dissecting gene × environmental effects on wheat yields via QTL and physiological analysis

Crops frequently display genotype × environment interaction for yield and end-use quality in response to different environments, particularly when stresses such as water limitation and temperature are components of the interaction. Plant breeders usually exploit this variation via phenotypic selection to develop varieties with both general and specific adaptation. However the individual genes and physiological processes underlying the basis of general and specific adaptation have rarely been elucidated. We are combining large-scale QTL analysis of several doubled haploid populations of wheat, grown over different environments and seasons, with detailed physiological analysis, to dissect the genes and mechanisms responsible for yield and yield × environment variation in adapted European winter germplasm. Analysis of populations grown under irrigated and non-irrigated conditions on drought-prone soils has revealed individual genes showing stable and differential expression over environments, and the analysis has also identified physiological traits that contribute to differential yield performance. Genes on the homoeologous group 2 chromosomes were associated with flag leaf senescence (stay-green) variation and were the most significant in drought interactions. Variation for stem soluble carbohydrate reserves was associated with the 1RS arm of the 1BL/1RS translocated chromosome, and was positively correlated with yield under both irrigated and non-irrigated conditions, and thus general adaptability. Separate analyses of populations grown over three seasons in England, Scotland, France and Germany revealed QTL for yield performance showing both general and specific effects. A stable QTL on chromosome 6A, consistent in different populations, showed significant effects over seasons and environments, whilst other QTL were specific to season and/or environments.     

Die Ertragsentwicklung von Wintergetreide und Zuckerrüben bei dauerhafter Senkung des N-Düngungsniveaus

Effects of Long-term Fertilizer N Reduction on Winter Grain and Sugar Beet Yields
The results of recent field experiments concerning the effect of long-term N-reduction on the yield and quality of sugar beet, winter wheat and winter barley on plots which had previously had received ample amounts of N are studied in this paper.
The yield and quality of crops harvested on plots where N-dressings had been reduced for 6–8 years were similar to those of crops grown on plots where N-application had been reduced for only 1 year. Grain yield of winter wheat and winter barley grown without any N-application decreased to about 60 % of amounts normally harvested under local conditions with recommended N dressings, whereas the white sugar yield still remained at 90 %. The yields decreased slightly with an increase in the duration of the experiments. Yields of both cereals and beets remained constant within each level of fertilization, even 6 years after inition of trials with 50, 75 and 125 % of locally recommended N dressings.
On plots that did not receive nitrogen fertilization, N-contents of grain were between 1.5 and 1.7 % for winter wheat and 1.0 and 1.6 % N for winter barley. These contents remained constant over a trial period of 6 years. The amount of annual export of 55–91 kg N/ha also remained constant. Limited N availability causes a decrease in grain protein content rather than in grain yield.
Compared to winter grain species, sugar beet (with 74–117 kg N/ha in the beet body) could realize the highest annual export of nitrogen from the plot. Differences in annual N export existing between the various locations of the plots cannot be explained by differences in soil quality. Continuous high yields that were found even without any N-dressings may be explained by asymbiotic N-fixation, deposition of atmospheric N and a progressive decrease in soil N with 17–56 kg N/ha removed from soil resources annually.     

Breeding progress for yield in winter wheat genotypes targeted to irrigated environments of the CWANA region

The international winter wheat improvement program (IWWIP), an alliance between Turkey–CIMMYT–ICARDA, has distributed improved germplasm to different National Agricultural Research Systems (NARS) partners through international nurseries and yield trials for the last 25 years. This study was carried out in order to determine the rate of breeding progress for yield and yield related traits at IWWIP using data of the international winter wheat yield trials (IWWYT), IWWYT 1–13, collected from 1997 to 2010 in irrigated environments across different countries. The relative grain yield of the best line expressed as percent of the best check (Kinaci-97), widely grown cultivar (Bezostaya) and trial mean (TM) increased at a rate of 0.6, 1.6 and 0.2 %/year, each non-significant (P > 0.05), respectively. Regression analysis indicated that TM has increased at a rate of 91.9 kg/ha/year (P = 0.007). The net realized breeding progress was estimated by accounting the variability due to management and weather conditions using surrogate variables such as integrated biological indices taken as means of common checks. The net realized gain for the BL was 66.2 ± 19.7 kg/ha/year (P = 0.01). Success rate of the BL, per cent of sites where the BL exceeds the local check in grain yield, ranged from 50 to 87 % across trials. To date, more than 55 varieties of IWWIP origin have been released in 10 countries of Central and West Asia including Afghanistan, Turkey, Iran, Uzbekistan and Tajikistan. Some varieties, such as Solh and Kinaci-97, have been released under different names in different countries indicating their broad adaptation. Cluster analysis of IWWYT sites indicated that IWWIP sites in Turkey and Syria are associated with most of the testing sites in Central and West Asia and North Africa (CWANA) region. The recently identified high yielding genotypes are recommended for direct release and/or parental purposes by the respective NARS.     

Yield of synthetic backcross-derived lines in rainfed environments of Australia

Wheat is one of the major food crops in the world. It is Australia’s largest crop and most important agricultural commodity. In Australia the crop is grown under rainfed conditions with inherently important regional environmental differences; wheat growing areas are characterized by winter dominant rainfall in southern and western Australia and summer rainfall in northern Australia. Maximizing yield potential across these diverse regions is dependent upon managing, either genetically or agronomically, those factors in the environment that limit yield. The potential of synthetic backcross lines (SBLs) to increase yield in the diverse agroecological zones of Australia was investigated. Significant yield advantages were found for many of the SBLs across diverse environments. Depending on the environment, the yield of the SBLs ranged from 8% to 30% higher than the best local check in Australia. Apart from adaptation to semiarid water stressed conditions, some SBLs were also found to be significantly higher yielding under more optimal (irrigated) conditions. The four testing environments were classified into two groups, with the northern and southern environments being in separate groups. An elite group of SBLs was identified that exhibited broad adaptation across all diverse Australian environments included in this study. Other SBLs showed specific adaptation to either northern or southern Australia. This study showed that SBLs are likely to provide breeders with the opportunity to significantly improve wheat yield beyond what was previously possible in a number of diverse production environments.     

Breeding aspects of clustering winter wheat cultivars for yield response

The objective of this study was to compare the yield response of several present day winter wheat cultivars of different origin with the aim of broadening breeders' information from multi-year/location tests by using an appropriate cluster procedure. Yield response of 18 cultivars was analysed using data from two series of official yield performance tests in Germany. Similarity of yield response between two cultivars is defined by a positive correlation coefficient (nearly one) for the yields over all test environments. A hierarchical agglomerative procedure was used to establish clusters of similarly responding cultivars. The smallest distances in yield response were established between closely related cultivars of equal maturity. Clusters of cultivars with distinct maturity and also the groups of East and West German cultivars tested exhibited clear differences in yield response.     

CIMMYT's approach to breeding for wide adaptation

Summary The wheat area in developing countries, including China, is around 100 million ha. To address the needs of these very diverse wheat growing areas, CIMMYT has defined 12 wheat mega-environments (ME). A ME is defined as broad, not necessarily continuous often transcontinental area with similar biotic and abiotic stresses, cropping systems and consumer preferences. The factors describing each ME are presented.CIMMYT's breeding methodology is centered around the development of widely adapted germplasm with high and stable yield across a wide range of environments. Segregating populations are alternating screened in two diverse environments in Mexico. One key requirement is that all germplasm is tested under near optimum conditions for its yield potential. The second one is multi-locational testing of advanced lines at sites that represent a given ME (key locations) and careful screening of germplasm for tolerance to abiotic and biotic stresses specific to that environment. This methodology has permitted the pyramiding of a large number of multiple resistance genes for use against a wide spectrum of diseases and tolerance to abiotic stresses within each ME. In addition, the widespread testing of lines allows the identification of traits which are beneficial in several environments. Data from international nurseries are used to further delineate environments within an ME. This approach has proven to be successful since around 70% of the spring wheat area in developing countries (excluding China) is planted to varieties derived directly or indirectly from CIMMYT germplasm. The performance of the bread wheat cultivar Pastor in international trials is given as an example for a wide adaptation.     

Classification of Global Environments and Cultivars of Spring Barley Based on Heading Time Interactions

Global heading time data collected by the International Center for Maize and Wheat Improvement (CIMMYT) during the International Barley Yield Trials were used to assess similarity of environments, variation among cultivars, and genotype × environment interactions. Data for 29 spring barley cultivars grown in 89 environments over three years were analyzed by cluster analysis. The deviation m days to heading of the mean of 28 photoperiod sensitive cultivars from the cultivar ‘Mona’ and the mean of ‘Mona’, homozygous recessive for the ea_k gene conferring photoperiod insensitivity and thermal stability, were used as environmental coordinates. In addition, diversity of heading time responses among genotypes was illustrated by differences among overall means and patterns of deviation for days to heading from ‘Mona’ in selected environments. Three main clusters were identified. Mexican environments were similar to warmer Mediterranean, eastern and southern African, West Asian, and Latin American environments. Heading time responses in Syria were similar to those observed m other cool Mediterranean environments. Early heading cultivars exhibited greater variation for heading response, especially in extremely warm-and equaiorial- short daylength environments, com-pared to late heading cultivars, presumably because of larger photothermal × genotype interactions. Photoperiod flux about the winter solstice appeared to be a major environmental cue for heading time in photoperiod sensitive spring barleys.     

Agronomic performance of winter wheat grown under highly divergent soil moisture conditions in rainfed and water‐managed environments

Even in the temperate climates of Europe, increasing early season drought and rising air temperature are presenting new challenges to farmers and wheat breeders. Sixteen winter wheat (Triticum aestivum L.) genotypes consisting of three hybrids, six line cultivars and two breeding lines from Germany as well as five line cultivars from France, Austria, Slovakia, Hungary and the Ukraine (referred to as “exotic” lines) have been included in this study. The genetic materials were evaluated over three growing seasons under a range of soil moisture regimes at the three North German sites Braunschweig (irrigated and drought‐stressed), Warmse (rainfed) and Söllingen (rainfed). The average grain yields in the twelve growth environments (water regime × season combinations) ranged from 6.1 to 13.5 t ha^?1. The exotic lines showed little evidence of specific phenological adaptation to drought although they are frequently faced with water scarcity in their countries of origin. The hybrids and German lines exhibited higher regression coefficients (b_i) to environmental means than the exotic lines, indicating particular adaptation to favourable growing conditions. The phenotypical correlations of grain yield between the various environments were high, ranging for instance from 0.6 to 0.8 for the irrigated and drought‐stressed environments at Braunschweig. It is thus expected that in the foreseeable future continued selection aiming at high yield potential will suffice as a means to counter the expected increase in droughts.     

Breeding winter wheat for a dual-purpose management system

Breeders attempt to conduct selection under environmental conditionsrepresentative of the target environment. In the U.S. southern Great Plains,more than 50% of the wheat area may be used for the dual purpose ofproducing forage for cattle grazing and harvesting grain, but breeding ofcultivars likely occurred in an environment managed for grain production.We tested the hypothesis that genetic improvements accrued over time inagronomic performance may be compromised, or be differentiallyexpressed, in a forage-plus-grain system compared to the grain-only systemunder which improvement was initially targeted. Two field experimentswere conducted in each of three years, employing managementcomponents appropriate to each system, and using a historical set of 12cultivars chosen for their widespread adoption in the region. Substantialgenetic improvement has occurred in hard red winter wheat yield, withoutadverse effects on test weight or grain protein content. The magnitude ofgenetic gain was higher in the grain-only management system under whichthese cultivars were originally selected. In two of the three years, we foundno significant trend for improvement in grain yield under the dual-purposesystem, prompting an expansion of our breeding objectives to incorporateselection pressure for dual-purpose adaptation.     

Specific adaptation of barley varieties in different locations in Ethiopia

Barley is one of the most important cereal crops grown for the livelihoods of the poor farmers of Tigray region in northern Ethiopia. As many low input and marginal environments it has benefited less from the yield increases achieved by modern breeding. This has been largely attributed due to genotype × environment intraction (GEI). To investigate the causes of GEI, ten barley varieties including local checks (two farmers developed varieties, four modern varieties and three rare local varieties) were tested over 21 environments. Participatory methods were applied to sample an adequate number of environments spanning the regional diversity. The yielding ability and stability of the varieties was graphically depicted by GGE and PLSR biplot. There were two major groups of environments, the central and northern highlands, the latter with less rainfall and poorer soils. Rainfall per month and total nitrogen level were the environmental variables that differentiated these two groups. In Tigray, rainfall in June and July were negatively correlated with yield, reflecting waterlogging problems. The different varieties were either specifically or widely adapted across the two environments. The variety ‘Himblil’, originating in Tigray, was the highest yielding and also most stable in the region of origin. However, it was inferior to improved varieties (Shege and Dimtu) at high yield levels. The association of earliness with grain yield indicates that the trait can be effectively manipulated within the existing materials. We recommend breeding for drought/water logging resistance based on selection in the target environment as the best strategy to provide stable and high yielding varieties for Tigray.     

Identifying high yielding stable winter wheat genotypes for irrigated environments in Central and West Asia

Improved winter wheat (Triticum aestivum L.) cultivars are needed for the diverse environments in Central and West Asia to improve rural livelihoods. This study was conducted to determine the performance of elite winter wheat breeding lines developed by the International Winter Wheat Improvement Program (IWWIP), to analyze their stability across diverse environments, and to identify superior genotypes that could be valuable for winter wheat improvement or varietal release. One hundred and one advanced winter wheat breeding lines and four check cultivars were tested over a 5-year period (2004–2008). Grain yield and agronomic traits were analyzed. Stability and genotypic superiority for grain yield were determined using genotype and genotype × environment (GGE) biplot analysis. The experimental genotypes showed high levels of grain yield in each year, with mean values ranging from 3.9 to 6.7 t ha⁻¹. A set of 25 experimental genotypes was identified. These were either equal or superior to the best check based on their high mean yield and stability across environments as assessed by the GGE biplot analysis. The more stable high yielding genotypes were ID800994.W/Falke, Agri/Nac//Attila, ID800994W/Vee//F900K/3/Pony/Opata, AU//YT542/N10B/3/II8260/4/JI/Hys/5/Yunnat Esskiy/6/KS82W409/Spn and F130-L-1-12/MV12. The superior genotypes also had acceptable maturity, plant height and 1,000-kernel weight. Among the superior lines, Agri/Nac//Attila and Shark/F4105W2.1 have already been proposed for release in Kyrgyzstan and Georgia, respectively. The findings provide information on wide adaptation of the internationally important winter wheat genotypes, and demonstrate that the IWWIP program is enriching the germplasm base in the region with superior winter wheat genotypes to the benefit of national and international winter wheat improvement programs.