m. roostaei

Kamal, is a new winter bread wheat cultivar developed by the national rainfed bread wheat breeding program for the cold and temperate dryland areas of Iran. New cultivar created by crossing between Sbn//Trm/k253 and 88Zhong218//Ctk/Vee/3/Kvz/Gv//Prl in Maragheh Research Station. Kamal was selected from segregating population from F2-F7 in Maragheh (2002-2008) based on agronomic characteristics. Based on results, Kamal grain yield means in preliminary and advanced regional yield trail was 2234 and 1719 kgha-1, respectively. Results of elite trail in cold and moderate research stations (2012-2015) showed that the grain yield mean of Kamal was 2120 and means of Azar2 and Ohadi cultivars were 2066 and 2083 kgha-1, respectively. Kamal cultivar in East Azerbaijan province was compared with conventional control cultivars in the farmer fields for 3 years and the results showed that the average grain yield of Kamal and checks were 2604 and 2230 kgha-1 respectively. Kamal is a winter type variety with time to heading of 143 days, 67 cm plant height, 40, gr. 1000 kernel weight, 11.4% protein content, 20 ml Zeleni numer, 41 degree of hardness, 27% wet gluten and 15 unit of gluten index. Results revealed that Kamal cultivar is tolerant to cold and drought stresses, with suitable earliness, and good bread quality but susceptible to yellow rust and leaf rust, this xultivar way and released in 2019 under the name of Kamal for cold and moderate cold dry areas of Iran.

Drought-tolerance and grain yield stability are among the most important aspects in adaptation and successful performance of rainfed winter bread wheat cultivars. The main objectives of this study were (i) to assess the effectiveness of drought tolerance indices for selection of drought-tolerant winter bread wheat genotypes, and (ii) to identify high-yielding genotypes with yield stability in variable environments. In this experiment, 24 winter bread wheat genotypes were evaluated in 12 yield trials under two moisture-regimes (rainfed and supplemental irrigation) in two dryland research stations differing in winter temperature (temperate and cold agro-climatic conditions) during three cropping cycles (2018-2021). Yield-based drought tolerance indices including; stress tolerance index (STI), geometric mean productivity (GMP), mean productivity (MP), tolerance index (TOL), stress susceptibility index (SSI) and yield stability index (YSI) were used to estimate drought tolerance levels of winter bread wheat genotypes across locations and cropping cycles. GGE-biplot technique was used for grain yield stability analysis. Combined-analysis of variance revealed that the main effects of cropping season, location, moisture-regime, genotype, and their interactions effects on grain yield were significant (P<0.01). The combined and yearly PCA-based biplots and correlation matrix analyses revealed that STI, GMP and MP were consistently correlated (P<0.01) with grain yield in either rainfed and irrigated environments, indicating the effectiveness of these indices for selection of high-yielding genotypes in both conditions. Based on these indices, G13 (Chenab/GB-SARA-27 IRW2009-10-023-0MA-0MA-0MA-0MA-0MA-6MA), G14 (Chenab/GB-SARA-27 IRW2009-10-023-0MA-0MA-0MA-0MA-0MA-7MA), G11 (Dharwar Dry/Nesser//SARA-BW-F6-06-85-86-2-5 IRW2009-10-056-0MA-0MA-0MA-0MA-0MA-6MA) and G22 (Unknown-2) were the most drought-tolerant genotypes. GGE-biplot analysis identified G11, G13 and G14 as high yielding genotypes with yield stability across environments. In conclusion, the genotypic variation for drought tolerance and grain yield stability found in this study should be further explored in the national rainfed winter bread wheat breeding programs in Iran.

Wheat is the most important staple food crop in the world as well as in Iran. About 63% of the wheat cultivation areas and 40% of its production is under dryland conditions in Iran. Water and nitrogen are the two most important limiting factors for wheat production in dryland conditions. However, the role of water is about 2.3 to 3.9 times the nitrogen because the water deficiency limits the absorption of the nutrients especially nitrogen. Nitrogen deficiency is very critical than the other nutrients for plant growth in the arid and semi-arid region. Therefore, applying supplemental irrigation (wherever it is possible) at the critical crop growth stages along with nitrogen fertilizer will increase wheat production by increasing the greenness and photosynthetic activity of the plant. In this regard, the cereal department of Dryland Agricultural Research Institute (DARI) has introduced different new wheat cultivars for supplementary irrigation conditions in the last decade. Hence, evaluating the response of bread wheat genotypes to different rates of nitrogen under supplementary conditions, determining the relationship between nitrogen requirement and water status of varieties as well as the relationship between these factors with yield components and effective traits to improve the quantity and quality of the crop, are the key factors for wheat production in dryland areas.

A field experiment was conducted to evaluate the response of dryland wheat (Triticum aestivum L.) genotypes to different rates and timing of nitrogen application under supplemental irrigation in 2018-2020 cropping seasons at DARI, Maragheh, Iran. The experimental design was a randomized complete block with three replicates based on split-split-split plot arrangement consisting of two irrigation treatments (50 mm in planting time and 50 mm in planting time + 30 mm at booting stage) in the main plot; nitrogen application time (fall application and split 2/3 in planting time + 1/3 in booting stage) in the sub-plot; four nitrogen rates (0, 40, 80 and 120 kg.ha−1) in the sub-sub-plot and three genotypes (Takab, Hoor and Griset-16 (sup-96-18) in the sub-sub-sub plots. The soil samples were collected from 0-25 cm depth before the sowing and were determined soil texture (loam to silty clay), pH, EC, Organic carbon, P (Olsen method), K (Sodium bicarbonate method), micronutrients (Fe, Mn, Zn, and Cu) by DTPA method. Because all these elements were more than critical levels (P: 10 mg.kg-1; K: 250 mg.kg-1; Fe: 5 mg.kg-1; Mn: 11 mg.kg-1; Zn: mg.kg-1 and Cu: 1.4 mg.kg-1) in the soil, only nitrogen rates were used in the experiment (Feiziasl et al., 2004; Feiziasl et al., 2009). The data was collected for biological and grain yield, yield components, plant height, spike length, nitrogen use efficiency (NUE), water use efficiency (WUE), and seed quality (Seed protein, Number of Zeleny Grain hardness, Grain starch). The GenStat14 software was used to combined analysis of variance and mean comparison of traits by Duncan's Multiple Range Test. The CurveExpert 2.6.3 software was used to fit equations, Excel to draw charts and Xlstat2016 software to do principal component analysis.

The first year of the experiment produced a significantly higher yield (P≤0.05) due to higher precipitations. Two stages of supplementary irrigation significantly increased biological yield, grain yield, and straw yield by 2975, 895, and 2069 kg ha-1, respectively. Although fall and split application of nitrogen had no significant effect on yield and yield components, fall application increased grain yield, NUE, and WUE by 195 kg.ha-1, 1.97 kg.kg-1, and 0.5 kg.ha-1.mm-1, respectively. Nitrogen application increased grain yield components for which the number of spikes per square meter was increased more than the two others. The nitrogen requirement of dryland wheat was determined 70 kg.ha-1 under single irrigation at planting time by fertilizer placement method while it was determined 90 kg.ha-1 for two stages supplementary irrigation for which 2/3 of it was applied at fall (planting time) and 1/3 at booting stage with supplementary irrigation.

 Although the interactions of irrigation, nitrogen rates, application times, and genotypes factors on grain yield were not significant, supplemental irrigation and nitrogen application could increase the yield production of dryland wheat genotypes.

In order to produce wheat lines with high tolerance to drought and cold stresses, Sadra variety was generated by a cross between Sardari (male) and promising line Azadi/Azar (female) in Maragheh research station. Results of studies in the cold and moderate cold research stations showed that the grain yield means of Sadra, Azar2 and Sardari cultivars were 2394, 2332 and 2214 kgha-1, respectively, so that grain yield of Sadra was 8% and 3% higher than Sardari and Azar2 check cultivars, respectively. Sadra has a good adaptability to different climatic conditions, so that the new cultivar possess a great potential to be more productive during years with higher precipitation. According to the results, the mean grain yield of Sadra, Azar 2 and Sardari cultivars under optimal rainfall conditions were 3330, 3045 and 2522 kgha-1, respectively. Sadra cultivar has good general adaptability and grain yield stability, winter growth habit, high tolerance to cold and drought stresses, date to heading of 137 days, plant height of 80 cm and 1000 kernel weight of 35 gr. One of the most important characteristics of Sadra is its bread-making quality, so that Sadra with Zeleni number of 33, protein content of 11.3%, hardness of 47, wet gluten content of 30, gluten index of 50 and SDS sedimentation volume of 55 has a great bread-making quality. Based on its high yield potential and other appropriate agronomic characteristics, Sadra cultivar was released for cultivation in the cold and moderate cold dryland conditions of Iran.

Release of new wheat cultivars with good characteristics such as high yield performance and resistance to diseases for specific regions under rainfed condition is an essential task for sustainability of wheat production. Saein was generated by crossing between: Azar2 and 87Zhong291 (with facultative growth type, high yield performance, good thousand kernel weight and resistance to diseases) in 1999-2000 in Maragheh Research Station. Grain yield means of Saein and Azar2 (as check cultivar) during 2006-2013 cropping seasons in Maragheh Research Station were 2601 and 2493 kgha-1 under rainfed condition and 3529 and 3223 kgha-1 with a supplementary irrigation at the sowing time, respectively. Results showed that Saein had also a specific adaptability in Ardabil regions and grain yield means of Saein (new cultivar), Ohadi and Azar2 (as check cultivars) in Ardabil were 1604, 1267 and 1355 kgha-1, respectively. Results of an on-farm study, in the farmer field in Ardabil province, showed that grain yield means of Saein and Azar2 during 2013-2014 cropping season were 2307 and 2275 kgha-1, respectively. The new cultivar is resistant to yellow rust, resistant to moderately resistant to leaf rust and also resistant to common bunt and dwarf bunt as well as resistant to cold damage, lodging and seed shuttering. New cultivar has winter growth type, white grain color, 76 cm plant height and 33 gr 1000 kernel weight. Based on its good characteristics, this line was released as a new wheat cultivar with the commercial name of Saein in 2015 and was recommended for cultivation in rainfed regions in Ardabil province, in the cold dryland areas in the north west of Iran and also in areas with the potential of supplementary irrigation.

In common natural gas pressure reducing stations, gas heaters and throttle valves are used for pre-heating and pressure reducing. The gas heaters are used to prevent the hydrate formation after the station because of temperature reduction. In this work, in addition to study the existence of gas heaters in common stations, four substitute methods are presented and together with the commonly used method are simulated for 5 hot-climate cities in Fars province, i.e., Darab, Lar, Lamerd, Mohr and Farashband. These four methods are comprised of: 1- Use of an expansion turbine in place for the throttle valve, 2- Use of an expansion turbine for pressure reduction and an electric heater instead of the gas-burning heater, 3- Use of a vortex tube for the throttle valve, 4- Use of an evaporation-condensation cycle instead for the gas-burning heater. Heating loads and gas consumption for the commonly used method and suggestive methods are compared. Furthermore, the work gained through the use of the expansion turbine was calculated and reported. The expansion turbine and vortex tube need most and least heating loads and gas consumptions for preheating, respectively. The expansioncondensation cycle need lower heating load because of its higher efficiency in comparison of the direct gasburning heater.

Behdan barley cultivar with pedigree of Soufara-02/3/RM1508/Por//Wi2269/4/Hml-02-ArabiAbiad//ER/Apm was introduced in 2007-2008 growing season through IBYT-LRA-M trial, which received from International Center for Agricultural Research in the Dry Areas (ICARDA). This cultivar was initially evaluated at Gachsaran Research Station and based on its higher grain yield (49% grain yield superiority compared to Izeh check cultivar) was selected. In the preliminary evaluation in 2008-09 growing season, Behdan had 64% and 34% higher grain yield compared to the check cultivars (Izeh and Mahoor), respectively. In the uniform regional preliminary yield trial in 2009-2010 growing season, Behdan had 13% higher grain yield compared to average grain yields of Mahoor and Izeh cultivars and in advanced yield trial in 2010-2011 growing season it had 3% and 7% higher grain yields compared to Mahoor and Khorram cultivars, respectively. Under farmer's conditions in Emamzadeh Jafar plain and Basht regions in 2014-2015 growing season, Behdan had 10% and 7% higher grain yields compared to Mahoor and Khorram cultivars, respectively. The protein content of Behdan barley cultivar was found to be 12.5%, indicating its good quality for feeding.

Experiment was conducted to evaluate the effect of different levels of egg yolk for coating and storing spermatozoa. Ejaculates were collected from four rams. In each session، second ejaculates (n=4) were collected in a tube containing 1 mL coating buffers which were prepared by 10، 15 or 20% egg yolk plus Tris-fructose. Samples were pooled، centrifuged and the supernatant removed in the laboratory. The pellets were diluted with Tris-fructose containing egg yolk which was equal to its concentration in coating. To perform four replicates for each sample، diluted sample was split into four parts then each part was split into two fractions. One of them (cold-shock) was suddenly put on ice water and the other was chilled at 0. 25°C/min until 5°C. Aliquots were kept at 5°C for 36 h and sperm motility، viability and functional membrane integrity were determined at 0، 12، 24 and 36 h. The results showed that functional membrane integrity was highest in 20% yolk egg under gradual cooling at 0، 24 and 36 h (85. 7، 75. 9 and 71. 7%،respectively; P<0. 05). In the presence of 20% egg yolk، sperm viability was highest under cold-shock (74. 8%) and gradual cooling (78. 5%) and sperm motility was lower in cold-shock than gradual cooling at all storage times (76. 9، 60. 7، 36. 2 and 27. 7% vs. 85. 4، 73. 1، 54. 6 and 40. 8%، respectively; P<0. 05). Therefore، 20% egg yolk can improve coated sperm longevity in normal gradual cooling; but it does not prevent the destructive effect of cold-shock from taking place.

In order to study the effect of supplementary irrigation on grain yield of 20 advanced bread wheat lines from population of recombinant inbred lines, selected from Azar2/87Zhong291, this experiment was conducted using randomized block design with three replications under supplementary irrigation during 2008-09 seasons at the Dryland Agricultural Research Institute (DARI) of Maragheh. Characters under study were: days to heading, plant height, days to maturity, 1000 kernel weight, tiller number, spike length, seed number per spike, spikelet number per spike, peduncle length, leaf sheath length, grain and biologic yields. Analysis of variance revealed significant differences among genotypes with respect to the most of the traits studied. Results showed that the lines No. 4 and 16 with 3400 and 3680 kg/ha grain yield were significantly superior under supplementary irrigation conditions. Based on the results the traits such as leaf sheath length, seed number and spike weight, tiller number and HI showed positive and significant correlation with grain yield. Path analysis indicated that leaf sheath length, seed number per spike and 1000 kernel weight were important traits to select lines for high yield potential under supplementary irrigation condition, but days to maturity showed negative effect on grain yield. As a whole, the line no. 16 (Azar2/78Zhong291-53) with high yield (3680 kg/ha) under supplementary irrigation, early maturity, 1000 kernel weight and HI, can be selected as a suitable genotype.

In order to study the the effects of planting dates on durum wheat cultivars and lines, this experiment was conducted in 1997/98 and 1998/99 cropping in Maragheh region. The experimental design was strip plot based on RCBD, with three replication. Horizontal factor was allocated to two planting dates (early planting in early October, and late planting in late November), and vertical factor was 11 durum wheat cultivars and lines. In different plant growth stages some agronomic traits and grain yield were recorded. The results showed that, effect of planting dates on number of days to heading and maturity was significant (?=1 %) however, effects on other traits were not significant, but the first planting date had more grain yield than the second date. The effect of cultivar on number of matured tillers, number of seeds per spike, spike length, spike weight, plant height, days to heading and maturity and grain yield was significant (? = 1%), but its effect on grain filling duration was not significant.