To evaluate the effects of wheat (Triticum aestivum) and Oilseed rape (Brassica napus) strip intercropping on yield components, seed and biological yields of Oilseed rape, field experiments were carried out as factorial based on randomized complete block design with three replications at Research Farm of Tabriz University, Tabriz, Iran during 2010-2012 cropping seasons. The first factor consisted of four types of wheat and Oilseed rape cropping system, sole crop of Oilseed rape (A1),: strip intercropping with 8:3 (A2), 12:4 (A3) and 16:5 (A4) of wheat and Oilseed rape rows, respectively and the other factor consisted of two fertilizer levels, B1: 100% chemical fertilizers (urea and triple superphosphate) and B2: 50% chemical fertilizers + biofertilizers (Nitrazhin and Barvar2). The results showed that strip intercropping of wheat- Oilseed rape resulted in significant increase in yield components, seed yield per occupied unit area and biological yield per occupied unit area of Oilseed rape as compared with mono-cropping. The number of silique per plant in intercropping systems was significantly higher than that of mono-cropping. The highest seed yield was obtained in the 16:5 rows of wheat-Oilseed rape with 343.76 g.m-2 and the lowest mean was observed in mono-cropping of Oilseed rape with 260.21 g.m-2. Biological yield per occupied unit area and seed yield per intercropped unit area in B1 were significantly greater than that of B2, but this treatment had no significant effect on the other traits. Because, B1 and B2 had no significant difference in seed yield per occupied unit area and due to the importance of reduction in chemical fertilizers consumption and food and environmental health care, strip intercropping of wheat-Oilseed rape under 50% chemical fertilizers + biofertilizers can be recommended as a suitable cultural method.

In order to determine tolerant Oilseed rape genotypes to terminal drought stress, 13 Oilseed rape genotypes including Karaj1, Karaj2, Karaj3, Talaye, Zarfam, Okapi, Licord, SLM046, Modena, WPN5, Opera, WPN2 and GKH305 were evaluated in agricultural research station of Islamabade Gharb since 2010 for two growing season. Oilseed genotypes were planted using randomized complete block design with three replications under normal and drought stress conditions so that irrigation was cut from flowering stage. Combined variance analysis showed that the effect of terminal drought stress was significant for recorded characters except oil content, the number of branches and 1000 seed weight. Results showed that mean of seed yield decreased by 20% due to drought stress so that seed yield in normal and terminal drought stress conditions was 4586 kg/ha and 3736 kg/ha, respectively. This reduction was because of drought stress effect on yield components i. e. pods per plant and seed per pods. Genotype GKH305 had the highest seed yield with 5230 and 3941 kg/ha in normal and drought stress conditions, respectively. Bi plot derived from principal components showed that GKH305, WPN5 Zarfam and had high seed potential meanwhile were tolerant to drought stress. In current study, well known genotypes namely Licord, Talaye and SLM046 had low seed yield under both conditions. Introduction Environmental stresses are the most important factors reducing the yield of agricultural products worldwide. Drought is one of the most common environmental stresses that have limited agricultural production and decrease the efficiency of using dry and dry areas. In the field of drought stress, many experiments have been carried out in the world, but in most cases, the severe interaction between the environment and the genotype, selection of drought tolerant varieties is difficult. Improvement of drought tolerant cultivars is also one of the research priorities of the country. The effect of drought stress on plant depents on genotype, length of drought period, climatic conditions and plant growth stage (Roa & Mandham, 1991). The occurrence time of drought stress is more important than severity of drought stress (Kazi et al., 2002). rapeseed plants, which are cultivated like wheat in both dry and wet conditions, generally experience drought stress during their life cycle. In irrigated areas and areas where surface water is used for irrigation, due to the reduction of rainfall and the use of water resources for the lucrative spring crops, the amount of water is severely depleted. As a result, the intervals between irrigation periods will be long and and plants encounter with water stress during filling seeds. According to some studies, the most sensitive time for irrigation is the flowering and early flowering stage (Richard, 1978; Richard & Thrling, 1978; Richard & Thrling, 1979; Richard & Thrling, 1979b; Pouzet, 1995). the country's largest cultivation of rapeseed belongs to the northern provinces of the country due to the presence of humidity and rainfall in these areas. However, cold and temperate cold regions like Kermanshah have a good potential for growing canola. In these areas, one of the main problems of canola cultivation is the lack of proper rainfall during the flowering stage of rapeseed and later. In these areas, rapeseed farmers who, in addition to canola, cultivate corn or wheat, canceled the canola irrigation in April, and irrigate wheat and corn, and the cut off of irrigation of canola at flowering and seeding time caused Stress and reduction of canola production. Therefore, identifying genotypes tolerant to late season drought stress in rapeseed is of great importance. In this study, in addition to investigating the effects of drought stress on yield and yield components of rapeseed, the most resistant genotypes to late drought stress were identified.

It is necessary to understand the performance potential and the gap between the actual yields of crops with the achievable function so as to diagnose the limiting factors of performance. The present study has been conducted based on CPA Method in 50 fields of Zavkooh villi (Kalaleh, Golestan, Iran) in 2016 and 2017. The study has measured and recorded all information related to management practices, soil characteristics, and farmer socio-economic status. Furthermore, using stepwise regression, the Comparative Performance Analysis (CPA) Method considers the relation between the variables and yield, with the yield gap rate as well as its causes being estimated to reveal each factor’ s contribution to the creation of the yield gap. Results show that there is a 1818 kg per hectare vacuum between the average real yield (2308 kg ha-1) and the yieldable one (4123 kg ha-1), . Accordingly, the most important factors of yield gap in the region include field size (21. 4%), summer plowing (15%), the time of land preparation and plowing (14. 7%), nitrogen fertilizer (14. 6%), potassium fertilizer (14%), weed density per unit area (10. 8%), seed treatment (8. 1%), and Sub-soiler (1. 4%).

Canola (Brassica napus L.) is one of oil crops being cultivated in many areas of Iran. Its molecular breeding and production of varieties with new characteristics using genetic engineering needs the establishment of efficient transformation methods in commercial varieties. In this research transformation potential of 8 commercial cultivars; Licord, SLM046, RGS003, Zarfam, Okapi, Sarigol, Modena and Opera adapted to different regions of Iran was studied using cotyledon and hypocotyl explants. Agrobacterium tumifaciens, strain AGL0 containing the plasmid pCAMBIA3301 was used for transformation. Cotyledon and hypocotyl explants after inoculation with Agrobacterium were co-cultivated on MS medium containing 1 mg/l 2, 4-D and 4.5 mg/l BAP, respectively. Cotyledonary explants after co-cultivation were transferred on selection MS medium, containing 4.5 mg/l BAP and 3 mg/l phosphinothricin. Hypocotyl explants were transferred on selection MS medium containing 4 mg/l BAP, 2 mg/l Zeatin and 5 mg/l phosphinotricin. The regenerated plants were analyzed by PCR and histochemical GUS assay for gene transformation. The results showed that most of genotyes had gene transformation potential regenerated from hypocotyl segments, while this potential was limited to some cultivars using cotyledon explants. Among transgenic plants, using hypocotyls, Licord cultivar had the most transformation rate (15.26%) and Sarigol the least (0.2%). Also among regenerated plan's from cotyledon, SLM046 cultivar had the most transformation frequency (4.7%) and Modena, Opera and Zarfam cultivars did not respond to transformation.

In this study, the hypothesis that defense response in leaves of the Oilseed rape is induced under isothiocyanate stress was investigated. The effects of different concentrations of of methyl and propyl isothiocyanates (0, 1, 10 and 100 mM) were evaluated on accumulation of hydrogen peroxide, phenolic compound content and PAL and GST enzymes activities in Brassica napus L. Oxidative stress in isothiocyanates treated Oilseed rape plantlets was deduced from increment of percentage of electrolyte leakage and from accumulation of hydrogen peroxide. Results showed that the PAL activity was significantly correlated to the contents of phenolic compounds in response to isothiocyanates. Results also showed that GST activity was induced in Oilseed rape plantlets in response to exposure to 1mM isothiocyanate. Results suggested that production of total phenolic compound was not the only means of detoxifying in the Oilseed rape plantlets and glutathione conjugation was also involved in the defense response to toxification in Oilseed rape.

Background and Objective: The present study was carried out to determine the seeding rate for some hybrids and open-pollinated genotypes. Materials and Methods: A field experiment in a factorial experiment based on randomized complete block design was conducted at the Islamabad-Gharb Research Station during 2018-2019. Seed consumption was four levels of 2, 4, 6 and 8 kg. ha-1 and cultivars include hybrids (Natalie, Neptune and Marathon), open-pollinated (Nafis, Rohan, Nima) and R15 line. Results: The results showed that the effect of seed consumption was significant on plant height, number of branches, pod per plant and seed yield. The Maximum plant height was obtained at the level of 8 kg of seed and it was significantly different from all other seed consumption. However, the highest number of shoots and pods per plant resulted in the lowest seed density. Seed yield had a different reaction to seed consumption. The highest seed yield was obtained at 6 kg per ha seed consumption (2919 kg. ha-1) However, there was no significant difference between the levels of 4, 6 and 8 kg. ha-1. Marathon produced the highest seed yield with an average of 3585 kg per ha. Oil content was also different between the cultivars and the highest percentage was obtained in Natalie, Neptune and Nima. Conclusion: In general, the best results were in seed consumption of 6 kg/ha and Marathon hybrid. The target density recommendations for hybrid seed are lower than open pollinated genotypes.

Oilseed rape (Brassica napus L. ) is one of the most important oil crops severely affected by heat or drought stress. Although the acreage and production of Oilseed rape have been increasing steadily in the world, there are still serious concerns about edible oil demands supply for 9. 1 billion by 2050. In addition, ongoing climate change and the susceptibility of Oilseed rape to abiotic stresses threaten Oilseed rape production in many parts of the world. Oilseed rape crops are particularly concerned with more frequent heat and drought stress. By facing Oilseed rape crop with heat or drought stress, reduction in yield and yield component, oil concentration and change in fatty acids composition and phenological traits would be expected. On the other hand, there are several ways to mitigate the severe response of the plant to heat or drought stress such as detecting tolerant genotypes and modifying the planting method, sowing date, and tillage system. Additionally, optimization of plant growth regulators, fertilizers, bacterial growth regulators, and superabsorbent polymers is recommended to decrease the negative effects of drought or heat stress. Therefore, although heat or drought tolerance causes yield reduction but utilizing appropriate methods could reduce their disastrous effects.

Cold damage to winter Oilseed rape is caused by temperatures around 0ºC during early fall and spring and below 0ºC during winter. The study was conducted in factorial experiment with two factors, planting dates (Sept. 11 and Sept. 26) and six promising genotypes with three replications at Agricultural Research and Natural Resources Center of East Azarbaijan during 2003-4. The results indicated that the genotypes in second planting date produced lower number of leaves, crown diameter, dry weight, seed and oil yields. Correlations of seed and oil yields with leaf numbers per plant, crown diameter and plant dry weight were positive and significant, while they were negative with percent of cold damage. It seems that the leaf number, crown diameter and plant dry weight can be used for determining cold tolerant genotypes and suitable planting dates of winter Oilseed rape when freezing  temperature prevails.