gholam reza abediasl

IntroductionDurum wheat (Triticum turgidum var. durum) is grown for human consumption, mainly as pasta products, e.g., spaghetti and macaroni, couscous, bulgur, frike, flat breads, etc. Worldwide, the area annually planted to durum wheat is estimated to be around 17-18 million hectares, i.e., 8 percent of total wheat area, with a production averaging about 30 million tons annually, which is 5.5 percent of total wheat production. Although durum is grown in various regions of the world, the great bulk of durum area and production is concentrated in the Mediterranean basin and North America. Eight countries (Algeria, Canada, Italy, Morocco, Syria, Tunisia, Turkey, and USA) account for nearly two thirds (2/3) of world durum area and production. In Iran, the area under durum cultivation is about 400-500 thousands hectares with an annual production of 400-500 thousand tons, which covers about 60% of country demands. In spite of the importance of durum for Iranian rural economies, the country has not all succeeded in its research and development efforts to substantially improve durum productivity. The combinations of increasing demand for durum and durum products, as a result of demographic pressure, and relatively low durum productivity partly due to abiotic stresses (i.e. cold, terminal heat, moisture and nutrient deficiency stresses) made the country to an importer of durum. These are frequently exacerbated by biotic stresses, e.g., diseases and insects that may severely inhibit crop growth.
Materials and methodsThe main purpose of this study was to achieve high yielding durum wheat genotypes with higher yield stability in different environmental condition, tolerance to environmental stresses such as cold damage, drought and end of season heat stress. Hence, 17 durum wheat lines were evaluated for grain yeild and morphlogical traits in Maragheh, Sararood, Qamloo, Ardabil and Shirvan agricultural research stations in 2011-14. In each location, the experiments were conducted in a randomized complete block design with three replications.
Results and discussionBased on combined ANOVA, there was significant difference among the environments, genotypes and G×E. GGE-biplot models showed that the 5 environments were belonged to 3 mega-environments, and different genetopes had higher yield in each mega-environments. Sumplimentary irrigation, at sowing time and flowering growth stages, could increase grain yield of lines 30 and 70 percent in Maragheh and Qamloo locations, respectively. The increase of grain yield was 42 percent for line Rascon under suplimentary irrigation. The AMMI and GGE results also confirmed genotype 5 was the most high-yielding durum line with reasonable yield stability in cold areas (Maragheh, Qamloo and Ardabil). Also, genotype 13 was the most high yielding and stable line in Sararood. Hence, these line can be candiatted to release new durum varieties for cold and moderat rainfed areas. Complementary irrigation could increase grain yield up to 30 and 70 percent in Maragheh and Sararood, respectively.
ConclusionsIt can be concluded that finding of new stable high-yielding durum lines, with better performances than that the existed varieies, is a great progress in durum breeding programs in cold rainfed areas. Both GGE biplot and AMMI analyses could be used in grain yield stability and adaptability under rainfed conditions and sumplementary irrigations, however, the results of GGE biploet were more applicable and can be use extensively in the study of grain yield adaptability and stability under rainfed and sumplementary irrigations conditions in durum wheat breeding programs.

Genotype × environment interactions make it difficult to release high yielding durum varieties for diverse environmental conditions. The main purpose of this study was to achieve high yielding durum wheat genotypes with higher yield stability in different environmental conditions, tolerance to environmental stresses such as cold damage, terminal drought, and heat stresses. Hence, 16 durum wheat lines were evaluated for grain yield stability and morphological traits in Maragheh, Sararood, Qamloo, Ardabil and Urmia Agricultural Research Stations in 2012-15. In each location, the experiments were conducted in a randomized complete block design with three replications. Based on combined ANOVA, there were significant differences among the environments (E), genotypes (G) and G×E. GGE-biplot analysis showed that the 14 environments belonged to 3 mega-environments, and different genotypes had higher yield in each mega-environments. The AMMI and GGE results also confirmed that genotypes 2 (G-1252) and 3 (61-130/414-44//…) were the most high-yielding durum lines with reasonable yield stability across environments. Also, genotype 10 was the most adapted genotype to Ardabil. Line 61-130/414-44//… had 60, 11, 31, 10 and 17% more yield than check line (Saji) in Maragheh, Sararood, Qamloo, Ardabil and Urmia under rainfed conditions, respectively. Hence, these lines can be candiates to release as new durum varieties for cold and moderate rainfed areas. Complementary irrigation could increase grain yield up to 14 and 68% in Maragheh and Sararood, respectively. It can be concluded that finding new stable high-yielding durum lines, with better performances, as compared to the existed varieties, is a great progress in durum breeding programs in cold rainfed areas. Moreover, the GGE biplot and AMMI analysis had good performance in adaptability and yield stability analysis in durum genotypes and could be used to evaluate durum genotypes at different locations over the years in durum breeding programs.

Because of unpredictable conditions in Mediterranean environments, successful crop production requires improved adaptation and yield stability to mitigate major abiotic stresses such as drought and cold. Consequently, the objectives of genetic improvement should include obtaining genotypes with high potential yield and stability in unpredictable conditions. The main objective of this study was to evaluate grain yield stability and adaptability of 25 durum wheat genotypes grown at seven agricultural research stations (Kermanshah, Maragheh, Qamloo, Shirvan, Uromieh, Ardebil and Ilam) for three cropping seasons (2011-2013) using the univariate and multivariate statistical methods. The combined analysis of variance showed significantly differences among the main effects due to environment and genotype x environment (GE) interaction. GE interaction sum of square was 15 times larger than that for genotypes, suggests the possible existence of sub-environmental groups for the genotypes. Grouping of environments was not repeatable among the years. Many of the durum brreding lines exhibited a high combination of yield and stability across both drought and cold environments, comparable to check cultivars. Evaluation of genotypes based on phenotypic stability statistics showed that breeding lines G8, G2, G7 and G11 and Saji cultivar had the best level of combination of yield and stability performances. Graphic analysis of GE interaction using the GGE (G GE) biplot model indicated that the cold environments of Maragheh, Ardebil, Qamloo, Shirvan and Uromia differed from moderate cold and warm environments of Kermanshah and Ilam in identifying specific adapted genotypes. Breeding lines with high yield productivity, average 1000-kernel weight and plant height and earliness were more adapted to moderate than cold environments. In this study the genetic materials were evaluated under two limiting factors (cold and drought) of durum yield production in highland rainfed conditions of Iran. Because of lower mean yield in 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 breeding lines compared to the check cultivars, indicating genetic improvement for both high yield and stability performances in durum wheat breeding program. Most breeding lines originating from the International Center for Agricultural Research in the Dry Areas (ICARDA) gene bank could be considered as a genetic resource for specific adaptation, and yield stability. However, durum breeding in the Mediterranean basin, particularly in Iran, has made little progress in cold regions and most progress was in warm and moderate cold regions, highlighting the difficulty to increase yield of durum wheat under cold conditions. The GGE biplot methodology, as has been shown to be very effective for analyzing GE interaction data, allowed a meaningful and useful summary of GE data and assisted in examining the natural relationships and variations in genotype performance among various testing environments. The finding that some test environments may be better than others for genotype evaluation suggests that the genotypes may be evaluated in fewer but more representative environments while still achieving the same or even better evaluation. Based on GGE biplot analysis, 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). In conclusion, current durum wheat selection may lead to yield stability and specific adaptation, which provides opportunities for this collection to be useful for genetic improvement of both drought and cold tolerance in durum.

Tak-Ab is a new winter bread wheat cultivar developed from evaluation of ICARDA-Turkey-CIMMYT international bread wheat germplasm to supplementary irrigation areas. Study of new cultivars under supplementary irrigation in Maragheh and Ardebil Research Stations (2005-2012) showed that, Tak-Ab had high grain potential under supplementary irrigation conditions. Based on results means of grain yield for Tak-Ab, Azar2 and Alvand with one time irrigation at sowing date were 3636, 2785 and 2556 kg ha-1 respectively. Average of grain yield of Tak-Ab and Azar2 with two times irrigation (Sowing Bolting) was 4737 and 4346 kg ha-1 respectively. Results revealed that this line is more tolerant to cold, moderate resistant to rusts and resistant to logging, thus it is suitable for supplementary irrigation in cold dry lands of Iran, and it has higher 1000 kernel weight and good bread quality as well. It is a winter habit and early maturity, 80 cm plant height, 36gr. 1000 kernel weight, grain color red and with 12% protein content. Based on these results, thenew line (Manning/Sdv1//Dogu88 OYC-OYC-OYC-12YC-OYC) was released in 2013 under the name of Tak-Ab.