Due to having Spring and autumn genotypes and adaptation to weather conditions, rapeseed is considered as a point hope to provide edible oil of country. Two separate experiments were set up as split-plot in a RCBD design with three replications in two fall and winter seasons during two years (2014-2015 and 2015-2016) at the research field of Seed and Plant Improvement Institute to investigate the effect of sowing season and date on the quantitative and qualitative yields of rapeseed genotypes in Karaj, Iran. In this study, the main plots were sowing dates (7, 17, and 27 October in fall sowing and 9 and 19 February, and 1 March in winter sowings) and sub-plots consisted of genotypes (RGS003, Dalgan, Zabol10, Hyola401, and Hyola4815). rapeseed genotypes grain and oil yields were 4330 and 1840 kg ha-1 in fall sowing, respectively, while these traits were decreased 43.3 and 46.6% respectively, when rapeseed genotypes were planted in winter season. The highest grain and oil yields (5033 and 2202 kg ha-1) belonged to 7 October sowing date in fall sowing, while 9 February had the highest grain and oil yields (2996 and 1248 kg ha-1) in winter sowing. In general, the Dalgan genotype is recommended for cultivation due to suitable agronomic traits such as number of silique per plant, number of grain per silique, silique length, 1000-grain weight, as well as high grain and oil yields in cold temperate regions with arid and semi-arid climates such as Karaj, Iran.

To study the effects of water deficit on physiological indices and indentification of drought resistant cultivars of rapeseed among common cultivars in Eastern-Azarbijan, an expriment was carried out at Research Station of Factually of Agriculture, University of Tabriz, Tabriz, Iran. Genetic material was constituted of Global, Puma, Regent, Eureka and PF 7045.91 from napus species, Sonja and Parkland from rapa species and two hybrids, Hyola308 and Hyola 401. The experiment was conducted using a splite-plot design arranged in RCBD with 8 replications. Irrigation treatments with two level control and water deficit, were considered as main factor and cultivars as sub factors. Water deficit treatment was created by with holding irrigation at 50% flowering. Four weeks after induction of stress, physiological characteristics, including leaf water potential, specific leaf weight, and relative water content along with plant height, shoot dry weight, number and length of silique were measured. Mean of all traits, studied except specific leaf weight, were decreased under water deficit condition. Among the cultivars, studied global, had potentially higher number of silique, leaf water potential and shoot dry weight under both normal and water deficit condition, Thus, not only this genotype can directly be grown under water deficit condition but also can be used as one of the parent in developing mapping populations for identification of quantitative trait loci (QTL) for traits contributing in drought resistance.

Sowing date is an important determinant of yield in canola. Cultivation of winter rapeseed cultivars in semi arid regions of Iran however it has high potential for production, but, mentioned cultivars are late maturity and this late maturity cause to that silique formation and seed filling periods mature in the same time with hot and dry weather condition. In contrast, Spring rapeseed cultivars are shorter growth duration and in this regard, identification of Spring rapeseed cultivars with high cold tolerance for autumn planting cause to early harvest. In order to investigation of Spring rapeseed cultivars reaction to Spring and autumn planting dates, an experimental was carried out in a split plot design based on RCBD with four replications for two years (2004-2006) in Karaj.Treatments were included planting season in two levels as main plots such as common planting date, autumn planting (27 September) and Spring planting (25 March) and Spring rapeseed varieties as sub plots in 24 levels.The results indicated that simple effects of planting season and variety and also interaction effect on silique per plant, seed per silique, 1000 seed weight, seed yield, oil yield, biologic yield and harvest index were significant at 1% level probability. In autumn planting, Hyola 401 with greatest 1000 seed weight and high seed per silique had the highest seed yield (4689 kg.ha-1) and Hyola 330 produced the maximum oil yield (2165 kg.ha-1), wherease RG 405.03 had the maximum seed yield and oil yield (2066 and 713.6 kg.ha-1, respectively) in Spring planting. On the basis of this result, some of Spring rapeseed cultivars with high cold tolerance and high potential such as Hyola 401 could be planting in early autumn at moderate cold regions of Iran like Karaj.

Excess salinity is one of the most important problems of agricultural production. rapeseed is a superior oilseed due to the high quality of oil, large amounts of polyunsaturated fatty acids and oil yield. rapeseed is classified as a semi-salt-tolerant plant although yields decrease more than in many other crops when salinity is higher than the threshold. Therefore breeding for increasing salt tolerance would be of interest. Changes of protein expression were investigated in a Safi7 tolerant genotype in order to identify the molecular mechanisms of salinity tolerance in rapeseed. NaCl concentrations of 0 (control), 150 and 300 mM caused a significant increase of Na+ content in leaves and a decrease of shoot dry weight, shoot height, leaf K+ content and the leaf K+/Na+ ratio. 110 repeatably-appearing protein spots were identified on two-dimensional electrophoresis (2-DE) gels and among them, 37 spots showed significant expression changes based on changes in the induction factor (IF). Among them, 5 spots showed significant statistically changes at the 95% confidence level, with 1 spot being up-regulated and the other four spots down-regulated. Identification of the spots was performed by LC-MS/MS mass spectrometry analysis. The identified proteins play a key role in energy production and photosynthesis. Our results indicated that these proteins can also play a role in rapeseeds tolerance to salt stresses.

The present study was conducted to determine high yielding rapeseed cultivars adapted to different agro-climatic conditions. The 22 Spring type rapeseed genotypes as well as a check cultivaer (Sarigol) were evaluated in a randomized complete block design with four replications in four locations for two cropping seasens (2000-02). Simple ANOVA of yield showed significant differences among the genotypes. In combined analysis of variance (based on 8 environments), the effects of locations and years were not-significant, but interaction effect of year x location was highly significant. Differences among genotypes were also significant, while the mean squares of genotype location and genotype * year interactions were not significant , however the mean squares of genotype * year * location interactions were significant. According to the Eberhart and Russell’s, mether genotype No. 21 (Hybrid Hyola401) with highest yield , coefficient of regression equal to unity and non- significant deviation from regression was the most stable genotype. Differences in grain yield of genotypes No.2 (S-2), No. 20 (Hyola308) and  No. 21 (Hyola401) were not significant, Therefore recognized as genotypes with average stability. Based on coefficient of variation (CVi), genotype no.3 (Cyclone) was one of the three stable genotypes followeing to Hyola 401 and S-2, coefficient of determination (R2) of these genotypes were  highly significant . Finally, based on simultaneous selection for yield and stability, the high yielding genotypes  No. 21 (Hyola401), No. 2 ( S-2) and  No. 20 (Hyola308) could be recominended Roz target enivaronments.

In order to evaluation of Spring rapeseed cultivars reaction to terminal drought stress, an experiment was carried out in a split plot design based on RCBD with four replications for two years (2006-2008) at the research field of Seed and Plant Improvement Institute in Karaj. In this experiment, irrigation treatments in two levels as main plot such as normal irrigation (irrigation after 80 mm evaporation from evaporation pan) and water deficit stress as no irrigation from stem elongation to end of growth and varieties as sub plots in 20 levels ( Sarigol, Goliath, Heros, Comet, Amica, SW5001, Cracker Jack, Eagle, Wild Cat, SW Hot Shot, Ogla, 19-H, Hyola 401, Hyola 60, RGS006, Hyola 420, RGS003, Option 500, Hyola 308 and Quantum ). The results indicated that water deficit stress decreased plant height, branch per plant, pods per plant, grain per pod, 1000 grain weight, biologic yield, grain yield, seed oil content and oil yield, but there was not significant effect on harvest index. Under normal irrigation, Hyola 401 with high grain in pod and 1000 grain weight had the highest grain yield whereas, in water deficit stress conditions, RGS003 with greatest grains in pod and 1000 grain weight produced the maximum grain yield and it had the highest stress tolerance index (STI) in comparison with others varieties. Also, Quantum variety with the lowest grain yield under normal irrigation (3492 kg.ha-1), water deficit stress (2948 kg.ha-1) and small STI had the more susceptive to water deficit.

To evaluate the effect of salinity on some quantitative and qualitative characteristics of Spring rapeseed cultivars, an experiment was conducted in the greenhouse conditions at Yasouj University as a factorial with three replications. Four salinity levels (1.92 (as control), 9.87, 19.6 and 21.94 dSm-1 (NaCl and CaCl2 with ratio 20 to 1 in Hoagland solution)) as a first factor and eight cultivars as second factors were used. Some important quantitative and qualitative charecters of cultivars were recorded during growing season. Results showed that effect of salinity, cultivar and interaction between salinity and cultivar on studied characteristics were significant. Results showed that with increasing salinity levels, all measured traits, significantly decreased, except for number of non-fertile pod per plant. Generaly, Hyola60 and Hyola330 cultivars that showed higher amount of grain yield and oil yield than other cultivars were introduced as the most tolerant cultivars. Also these two cultivars had less non fertile pod at high salinity levels. PP-401-15E cultivar had a weak response to high salinity levels (19.6 and 21.94 dSm-1), and, it was introduced as the most sensitive cultivar to salinity.

To evaluate terminal drought tolerance in promising lines of Spring rapeseed, using stress tolerance indices, this research was conducted in 2008-09 and 2009-2010 growing seasons in Safiabad Agricultural Research Center, Dezfoul, Iran. Eleven promising lines of Spring rapeseed as well as Hyola401 (check) were evaluated in two separate field experiments using randomized complete block design with three replications in non-stress and terminal drought stress conditions. Results revealed that L5 and L4 were more tolerant than other lines using Stress Susceptibility Index (SSI) and Tolerance Index (TOL). However, Stress Tolerance Index (STI) and Geometric Mean Productivity identified Hyola401 and L1 line as genotypes with higher yield in both non-stress and drought stress conditions. Considering all drought tolerance indices, Hyola401 and L1 were suitable and adapted genotypes in terminal drought stress conditions. Study of correlation coefficients between seed yield in non-stress and terminal drought stress conditions and STI, GMP and MP showed that these indices are suitable for identification of terminal drought tolerant promising lines of Spring rapeseed.

Introduction: Among the different environmental stresses, drought is a major limitation in reducing crop yields. rapeseed is a plant adaptable to areas with limited rainfall during winter and Spring and dry air at flowering, grain filling and maturity stages. Water deficit stress during pod filling stage in rapeseed reduces the number of grains per m 2, oil percent and grain yield. Positive and significant correlations were reported among grain yield with pod numbers per plant and grain number in a pod in winter genotypes of canola, under normal and drought stress conditions. Strong negative relationship between grain yield and canopy temperature during reproductive stage of Brassica napus L. genotypes have been reported. The results of studying rapeseed genotypes under drought stress indicated that the chlorophyll a and b content of all genotypes declined due to drought stress at flowering and grain filling stages, but greater reduction in grain yield was observed when stress was imposed at flowering stage. The objectives of this study were to recognize some of the physiological and agronomic characteristics related to drought tolerance in Spring genotypes of rapeseed and to study the grain and oil yields and yield components relations under normal and water deficit stress conditions. Materials and Methods: The experiment was carried out in the East Azarbaijan Agriculture and Natural Resources Research and Education Center (46 2 E, 37 58 N, 1347 m a. s. l. ) with semi-arid and cold climate according to Koppen climatic classification system, during 2015 and 2016 cropping seasons. The experiment was conducted as split plot based on a randomized complete blocks design with three replications. The experimental factors were drought stress with three levels: non-stressed and drought stress from flowering and pod formation stages and genotype in 5 levels: RGS003, Zafar, Sarigol, Zarfam and Dalgan. Each plot consisted of 6 rows in 5 meters. Plants were harvested on the 5 th th and 17 of July during the first and second years of experiment respectively. During harvest time, in order to control boarder effects, plants from the sides of each plot were removed. Measured traits were leaf temperature, relative water content, stomatal conductance, leaf chlorophyll index, pod number per plant, grain number per pod, 1000-grains weight, grain yield and grain oil percent. Ten plants in each plot were used to determine grain yield components. Moreover, seed oil content was determined by NMR (nuclear magnetic resonance) method. Results and Discussion: Occurring drought around flowering and pod formation stages led to a significant increase in leaf temperature and significant decrease in leaf relative water content, stomatal conductance, leaf chlorophyll index, pod number per plant, grain number per pod, 1000 grains weight, oil percent, grain and oil yields. But the effects of drought from flowering stage were too hard. Therefore, in case of water resources limitation, irrigation during flowering stage will be more important than pod formation stage. RGS003 genotype with higher relative water content, stomatal conductance and leaf chlorophyll index and lower leaf temperature, indicated the highest grain and oil yields. The highest grain and oil yields with 1120 and 466 Kg h-1 respectively were obtained from RGS003 under non-stress condition. Also RGS03 in all water conditions indicated higher yields and could be used to cultivate in areas with normal and limited irrigation water resources. The significant correlations among leaf temperatures, relative water content, stomatal conductance and leaf chlorophyll index with each other and grain and oil yields and yield components were seen. It seems that these traits can be used to select drought tolerant Spring genotypes of rapeseed. Conclusions: It can be concluded that Spring rapeseed is more sensitive to occurring drought stress from flowering than from pod formation stage. Thus, water supply at flowering stage could be more effective in rapeseed yield production. Leaf temperatures, relative water content, stomatal conductance and leaf chlorophyll index can be used to screen high yielding Spring genotypes of rapeseed for late season water deficit condition.

Abiotic stresses such as salinity, are factors that severely affects agricultural production. To evaluate the effects of salinity on some morphological and physiological traits related to salt tolerance of genotypes of Spring rapeseed cultivars in the vegetative growth stage, an experiment was conducted as a split plot form based on Randomized Complete Blocks Design using levels of salinity: zero (control), and mM sodium chloride with three replications were done in the research greenhouse of Tabriz university. In present study, dry weight of shoot and root, height, Na+ and K+ contents of leaves and roots, K+/Na+ ratios in leaves and roots were measured. Increasing salinity levels have significantly increase Na+ contents of leaves and roots and reduced traits such as height, shoot and root dry weight, K+ contents and K+/Na+ ratios of leaves and roots. Cultivars showed the most significant differences, this shows that high diversity of genotypes in salinity tolerance. Cluster analysis led to the separation of genotypes into four groups. Results showed that SAN-was the most tolerant and the Amica was the most sensitive to salt stress during vegetative growth, respectively. Therefore They can be used to identify genes loci determination and understand the mechanisms salt tolerance genes.