نشریه یافته های تحقیقاتی در گیاهان زراعی و باغی
سال نهم شماره 2 (پاییز و زمستان 1399)

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.

To evaluate the effect of different tillage methods (CT: conventional tillage, RT: reduced tillage, and NT: no-tillage), and residue management of corn on species diversity, density and dry weight of weeds, as well as yield and yield components of wheat, a 3-years trial was conducted using a split-plot experiment based on a randomized complete block design (RCBD), with three replications during 2014-2017 at the Research Center of Zarghan, Fars Province, Iran. Results showed that species diversity of weeds was affected by tillage methods and residue management, so that conservation tillage especially RT method decreased 30% of weed infestations. Over time, applying NT method increased perennial weed density, while CT and RT methods accompanied by residue retention reduced 60% of perennial weed density compared to NT method. Applying RT method and residue retention maximized grain yield of wheat (8113 kgha-1) up to 30% compared to residue removal. The highest harvest index (40.26%) was obtained by CT method and residue retention, but the maximum 1000-grain weight (40.18 g), grain number per m2 (20827 seeds), and biological yield (20084 kgha-1) were achieved by RT method and corn residue retention. In general, adopting RT bill age method and retaining 30% of corn residue is recommended for wheat-corn cropping system in fars provience.

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.

Investigation on adaptability of various olive cultivars in the Khuzestan climate conditions showed that most of the commercial cultivars in these regions were affected by the warm weather so that their yield and oil were strongly reduced. To obtain adapted olive cultivars with high yield and oil percentage, several studies were implemented at Safiabad Agricultural Research Center since 1998. Among genetic resources, a genotype, Avan, that had different oil accumulation process from other genotypes was identified. Preliminary evaluations showed that oil accumulation curve in Avan was double sigmoid and its oil content exceeded 20%, while the oil content in other local cultivars, such as Dezful and Zard, can rarely exceed 10%. For further evaluations, Avan plants were cultivated in Baghmalek, located in the east of Khuzestan province, in 2007. The results of experiments in Baghmalek also showed that the oil accumulation process of Avan had double sigmoid curve. The average yield of 6-years-old trees of Avan was 17 kg with 21% oil content in the fresh fruits. In contrast, the amount of oil content in Mavi (local olive cultivar in Baghmalek) was 10.5% and in Conservolia foreign cultivar this amount was less than 10%. Results of these studies showed that Avan is an adapted olive cultivar for subtropical regions with the ability to produce 5 to 7 tons of fruit and 1000 to 1200 kg of oil per hectare. Using Avan in subtropical regions of Iran such as east of Khuzestan, south of Fars and Kermanshah provinces and similar regions, can increase the yield of oil in olive orchards about 300-400 kgha-1. Avan is tolerant to biotic and abiotic stresses so that no signs of damage by pests and diseases as well as sunburn and drying on its branches have been observed so far.

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.

Climate changes along with recent droughts and short growth period of spring planting date are important factors causing non-economic and low yield production of chickpea in Iran. Ata variety with breeding code of x03TH148 was received from ICARDA in 2004 through Chickpea International Segregation Generations Nursery. This line was evaluated in international, preliminary, advanced and adaptability yeild trials as well as studies on fusarium wilt and ascochyta blight diseases resistance at agricultural research stations and under farmers’ fields conditions in autumn planting date.  Based on results of adaptability trials, this variety had suitable agronomic and economic characteristics such as potencial for machinery harvesting, average seed yield of 886 kgha-1, with 11% superiority to Jam check cultivar and cold tolerance to -16.9°C in the areas without snow covering during emergence. The new variety with average yield of 2061 kgha-1 showed considerable superiority to Saral check (1345 kgha-1) in farmers’ fields. Considering high seed yield, tall plant height, large seed size, suitable seed protein content, tolerance to ascochyta blight and fusarium wilt diseases and marketable traits, Ata was released and recomended for autumn sowing in the temperate and cold regions of Iran.

Lentil cultivar Sepehr was first introduced as FLIP 2005-53L line through LIDTN-L-08 ICARDA international nursery and was evaluated in Gachsaran and Maragheh stations in 2007-2008 cropping season. FLIP 2005-53L line in the cropping seasons 2008-2009 and 2009-2010 was evaluated in the preliminary and advanced yield trials in Gachsaran and Khorramabad research stations. After evaluating the results of advanced experiments, this line was selected to participate in the national uniform regional yield trial (2010-2013) in Gachsaran, Khorramabad, Gonbad and Moghan research stations. Stability analysis of genotypes grain yield in this experiment showed that this line had the lowest contribution in the interaction of genotype × environment using different statistical methods and also it had the lowest mean rank values ​​for non-parametric stability parameters as well as 19% increases in the grain yield (with grain yield of 1166 kgha-1) ‌ compared to the control cultivar Gachsaran (with grain yield of 978 kgha-1) and therefore can be considered as "one of the most stable genotypes" with high grain yield. FLIP 2005-53L line with average grain yield of 1902 kgha-1 in farmers field in the research-extension trials, had a 15% advantage of grain yield over control cultivar Gachsaran with grain yield of 1651 kgha-1. In addition to high grain yield, good yield stability, high resistance to fusarium disease, desirable 100-seed weight (4.2 g) and suitable plant type and plant height for machine harvesting were other reasons for releasing Sepehr cultivar. Sepehr cultivar is suitable for cultivation in subtropical regions of the country including Khuzestan, Fars, Kohgiluyeh and Boyer-Ahmad, Lorestan, Kermanshah, Ardabil (Moghan) and Ilam provinces.

Tolo common vetch forage cultivar with original name of VS-Jordan 2628 was initially entered to the country through ICARDA vetch nurseries in 1997-98 and it was evaluated in the adaptability test of the international germplasm at Kohgiluyeh and Boyer-Ahmad (Gachsaran) and Lorestan (Kuhdasht) provinces. In Gachsaran, Tolo was selected based on its grain yield of 1077 kgha-1 and higher grain yield compared to the local check and in Kuhdasht area it was selected based on its dry forage and grain yield of 1032 and 465 kgha-1, respectively. In the preliminary yield trial in 1998-99, Tolo had dry forage and grain yields of 4438 and 1719 kgha-1, respectively. Also, in the advanced yield trial in 1999-2000 it had dry forage and grain yields of 2430 and 1080 kgha-1, respectively, and exhibited significant superiority to the local check. In the elite yield trial which was conducted in 2000-01 in Kuhdasht and Gachsaran regions, Tolo with average dry forage and grain yield of 2840 and 1216 kgha-1, respectively, as well as mean of rank, standard deviation of rank and coefficient of variation of 4.5, 3.51 and 17.1% for dry forage and those of 1.5, 0.58 and 52.9% for grain yields, respectively, had superior performance compared to the other genotypes and check cultivar. Tolo cultivar, in on-farm experiments conducted in different regions of Kohgiluyeh and Boyer-Ahmad province during 2001-02, 2004-05 and 2013-14 cropping years, showed higher yield performance compared to the local check cultivar and other studied genotypes. Also, its forage quality was significantly superior to alfalfa and vetch cultivar Lamei. Other important characteristics of Tolo cultivar were high initial growth rate, rapid canopy cover, high grain filling rate and high 100-seed weight compared to local check.