جستجوی مقالات مرتبط با کلیدواژه « canola » در نشریات گروه « زراعت »

False chinch bug (Nysius cymoides (Hem: Lygaeidae)) is one of the most important pests of canola in Iran and causes  significant damage to this crop annually. In order to evaluate the resistance of canola cultivars to this pest, 12 cultivars included Arshitect, Okapi, Nafis, Atura, Nima, Gabriella, Koodiak, Garo, Brotus, Rohan, Deffusion, and Traviana were studied in a completely randomized design in the research farm of the Faculty of Agriculture of Kurdistan University in 2020 and 2021 years.  In this study several parameters related to the false chinch bugs (Weight and population density of the pest) and several plant parameters (secondary branches number, diameter of the main branch, pod length, flowering branch length, seeds number per pod, 1000 seed weight and seed yield) were evaluated. The results of data analysis showed that there was significant difference between cultivars in terms of some parameters including seed weight, plant length, pod length, number of seeds per pod, 1000 seed weight, and yield at a 5% probability level. Also according to the multivariate analysis of variance, there was no significant difference between the type of trap and the type of cultivar, but there was a significant difference between the types of traps. In total, using cluster analysis by Ward's method and based on Euclidean distance, 12 studied cultivars were divided into four groups: resistant, semi-resistant, susceptible, and semi-susceptible.

In order to identify important agronomic traits related to yield and introduce early with high-yielding cultivars in Brassica genus, 100 genotypes of six species of Brassica genus (B. napus, B. juncea, B. nigra, B. rapa, B. carinata and B. oleracea)were evaluated implementing latis square designs with two replications experiments at Sari Agricultural Sciences and Natural Resources University Research Farm during 2017-2018. The results of variance analysis showed that the studied genotypes have very significant differences with each other in terms of all agricultural traits. The results of mean comparison showed that genotypes from B. napus species has the highest yield and genotypes from B. rapa species has the shortest days to ripening with the lowest yield. The longest days to ripening was identified as genotypes from B. juncea species. The analysis of genetic correlations for all species revealed that yield of seed had a significant positive correlation with days to ripening, silique number per plant, thousand grian weight and grian number in silique. Results of stepwise regression analysis revealed that silique number per plant, 1000-grain weight, number of silique per plant and days to maturity had significantly effects on grain yield. The result of factor analysis showed three independent factors that explained 92% of the total variability, which were named ‘productivity’, ‘phenology’, and ‘thousand grian weight’, respectively. According to all three factors, B. napus, best species and Janetzika، Liragold، Hayola 401and Hayola 308 from B. napus species, were identified as the best cultivars concerning seed yield and early maturity.

The crisis of water sources limitation has signified the necessity of irrigation management of canola crop unavoidable. This issue is especially critical in the context of climate change, which is accompanied by changes in precipitation amount and patterns as well astemperature flucatations. The time-consuming and costly nature of field research and the spatial and temporal dependence of the results have caused crop growth modelling to be considered as an effective and acceptable technique in decision support systems under climate change conditions. In this regard, the DSSAT program is one of the most successful programs available for simulating the growth and development of crops. In this study simulation program for plant growth and development was used to predict growth and seed yield of canola in Dehgolan in Kurdistan province of Iran.

This study consisted of two phases; field and simulation studies. Statistical Downscaling Model (SDSM) was used to simulate climate data and forecast climate changes in the future. For the future climate, the set of CanESM scenarios including; RCP2.6, RCP4.5 and RCP8.5 scenarios, presented by the Canadian Earth System Modeling Center, were used. Then, the changes in the growth and yield of canola under the mentioned scenarios were studied in the four periods of 2021-2040, 2041-2060, 2061-2080, and 2081-2100 using the CSM-CROPGRO-Canola model in the DSSAT program. In field studies, two field experiments were carried out to calibrate and validate the output of the model in the research farm of the Kurdistan University in Dehgolan 2016-2017 and 2017-2018 cropping seasons.

The results of validation for weather and growth models showed that the models had sufficient accuracy to simulate climate variables and also the growth of canola. The simulation results illustrated that the growth characteristics of canola were affected by the negative effects of climate change under all scenarios and different time periods, therefore, the plant traits in various climate change scenarios were low when compared to the baseline cropping season (2018-2019). In general, the results of the model showed that the maximum negative effects of climate change on canola growth was in the RCP8.5 scenario and the minimum in the RCP2.6 scenario. The adverse effects of climate change were accelerated by time, especially in the RCP8.5 scenario.

The results of this study showed that the future climate change will have a negative effect on the growth and yield of canola that depends on the scenario and time period, the seed yield will decrease from 0.3% to 37.58% as compared with the current conditions. Therefore, to mitigate climate change impact on agricultural ecosystems necessary management measures including development of suitable canola cultivars and agronomic mangament package should be taken into consideration for adaptation to the changing climate in future.

In order to evaluate the tolerance of rapeseed genotypes to heat stress, an experiment was carried out in the two crop years of 2018-2019 and 2019-2020 in the experimental farm of Shahid Chamran, University of Ahvaz, Ahvaz. The experiment was conducted as a combine analysis in the frame of a randomized complete block design with three replications in two conventional sowing dates (normal conditions) and delayed planting dates (stress conditions) on 9 rapeseed genotypes (including 8 hybrids and one free-pollinating variety). The results of combine analysis of variance showed that the seed yield of the genotypes differed with each other at the probability level of 1%. Also, there was a significant difference between the environments (conventional and delayed cultivation) in both years and the year effects. The average yield of genotypes under normal and stress conditions in the first year was estimated as 3.467 and 1.667 tons per hectare and in the second year as 3.358 and 1.687 tons per hectare, respectively. The increase in yield under normal conditions in the first year compared to the second year was due to more rainfall and more suitable temperature in the first months of cultivation. In this experiment, the stress intensity was estimated at 0.51 in the first year and 0.46 in the second year, which indicated high stress intensity during two years. The delay in planting followed by heat stress caused a 48% decrease in yield per unit area in average. The results of the analysis of indices based on grain yield showed that harmonic mean indices, stress tolerance index, geometric mean productivity, and average productivity are the best indices in assessing heat tolerance in rapeseed. And these four indicators had a positive and significant correlation with performance in both normal and stressful conditions. Drawing a three-dimensional diagram based on grain yield under stress and normal conditions and the selected indices showed that Hayola 50 and Hayola 61 hybrids are more heat tolerant than other cultivars and hybrids and have higher yield stability under heat stress conditions. Therefore, for areas with heat stress at the end of the growing season, Hayola 50 and Hayola 61 hybrids are more suitable than other hybrids and are recommended for cultivation in those areas.

The aims of this study is evaluate AquaCrop in simulating rapeseed yield, biomass and water use efficiency under different irrigation amounts (E1, E2, E3 and E4, indicating water supply of 50, 75, 100 and 125 mm from the evaporation pan, respectivly) was performed in three cropping years (Y1, Y2 and Y3 representing the first, second and third years, respectively). In order to calibrate this model, the data collected from the first year used for calibration and data for the second and third year were used for validation. The results showed that AquaCrop had an overestimated error (MBE< 0) to simulate all three parameters studied. The accuracy of AquaCrop was excellent for simulating yield and biomass (NRMSE <0.1) and good for water use efficiency (NRMSE <0.2). The mean differences between simulated and observed yield, biomass and water use efficiency water were 0.19 t.ha-1, 0.78 t.ha-1 and 0.05 kg.m-3, respectively. Based on the results, use of AquaCrop to simulate rapeseed yield, biomass and water use efficiency is recommended.

Canola is one of the most important oilseeds that plays a major role in providing human edible oil and in this regard, it is in the third place after soybean and palm oil. There are many strategies to improve growth, yield and precocity in plant species including rapeseed. Seed priming is a pre-planting strategy that is very effective in improving germination, grow rate, seedling establishment and early maturity. As a result, considering the importance of increasing the quantity and quality of rapeseed and the positive effects that treatment has on improving germination, increasing yield and early maturity in rapeseed, In this study, investigating the effect of seed priming by gibberellin and salicylic acid on the characteristics of germination, growth and seed yield of canola was done.

In this research, a factorial experiment was conducted in a randomized block design with three factors. The first factor of genotype (Lord and Hayola 308), the second factor of salicylic acid (zero, 750, 1500 and 2250 μM) and the third factor of gibberellin (zero, 750, 1500 and 2250 μM) with three replications in research greenhouses of University of Agricultural Sciences and Resources Natural Sari was done in 1397. Canola seeds were immersed in the solution of the mentioned salicylic acid and gibberellin treatments for 24 hours at a temperature of 25 degrees Celsius. After passing the desired period, the seeds were washed with distilled water and completely dried on filter paper, which were immediately cultivated after drying. Germination percentage, first day of emergence, last day of emergence, time spread of emergence, day to maturity, 1000-seed weight, number of pods per plant, plant height, pod length, number of seeds per pod and yield were measured. At the end, all statistical analyzes of the data obtained from this experiment, after ensuring their normality, were performed using SAS and SPSS software.

The results of analysis of variance showed that seed priming by salicylic acid and gibberellin treatments had a significant effect on all traits except pod length at the level of one percent. The interaction of genotype with salicylic acid and the interaction of genotype with gibberellin were significant for all traits. The interaction of salicylic acid with gibberellin and the triple interaction of gibberellin with salicylic acid with genotype were significant for all traits except pod length. The results of mean comparison showed that the use of seed priming of salicylic acid and gibberellin, with increasing germination percentage, reducing the range of emergence and decreasing the day to maturity caused early ripening in rapeseed. In addition, by increasing the yield components such as number of seeds per pod, number of pods per plant, 1000-seed weight, height and length of pods, also increased grain yield. The results also showed that the combined application of 1500 μM levels from both treatments (salicylic 1500 × gibberellin 1500) has the greatest effect on increasing yield components and grain yield, so that grain yield in Lord genotype from 7.5 (gram per pot) to 12.1 (gram per pot) And in Hayola 308 genotype increased from 4.1 (g/pot) to 6.89 (g/ pot).

In general, the results showed that among the different concentrations of treatment, lower concentrations of these treatments were more effective in inducing prematurity and increasing yield. And among the cultivars used, Lord genotype has a higher but late yield, which can be solved by treating the problem of late maturity and as the best genotype in terms of early maturity and high yield under the influence of treatments, especially at the level of 1500 salicylic acid × Gibberellin introduced 1500 μM

Canola (Brassica napus L.) is one of the important oil plants in temperate regions, which has great value for humans and livestock as a producer of oil and meal. Phosphorus plays an important role in improving the quality and quantity of oilseeds, including rapeseed. Sufficient sources of phosphate are needed by the plant for earlier development and rooting and more foliage production in a short period of time. Considering the stabilization of phosphorus in the soil, the increase in the price of chemical fertilizers and environmental pollution, the use of biological fertilizers, especially the types of phosphorus-dissolving bacteria, play an important role in solving these problems. Therefore, the objective of this research was to investigate the role of phosphorus biofertilizer containing Pseudomonas fluorescens bacteria in improving the quantitative and qualitative yield of canola under the influence of chemical phosphorus fertilizer management.

A factorial field experiment was conducted based on a randomized complete block design with three replications at the research station of the Faculty of Agriculture of Yasouj University located in Deshtrum region in 2019. The first factor was triple superphosphate fertilizer at 6 levels (zero, 25, 50, 75, 100 and 125 kg/ha of pure phosphorus) and the second factor included phosphorus biological fertilizer containing Pseudomonas fluorescens bacteria at two levels (application and non-application). The traits of yield components, seed and biological yield, and seed oil and protein were evaluated. The traits of yield components, seed and biological yield, and seed oil and protein were evaluated. Yield components, seed and biological yield, and seed oil and protein were evaluated.

The results showed that phosphorus and bacteria chemical fertilizers had a significant effect on all investigated traits. The interaction of phosphorus chemical fertilizer and bacteria was also significant on all investigated traits except harvest index. The highest plant height (124.93 cm), number of lateral branches (4), leaf chlorophyll index (74.20), seed yield (5887 kg/ha) and biological yield (19411.4 kg/ha) were obtained in the treatment of 125 kg/ha of phosphorus and bacterial application. Also, with the consumption of 125 kg/ha of phosphorus fertilizer and the use of bacteria, the highest percentage and oil yield was obtained. Also, the results showed that there is no significant difference between the treatment of application of 50 kg of phosphorus fertilizer + bacteria and the treatments of application of higher levels of phosphorus fertilizer (75, 100 and 125 kg) alone.

Considering the superiority of 125 kg of phosphorus fertilizer along with bacteria in terms of grain yield, oil percentage and oil yield, it seems that these amounts of phosphorus fertilizer as well as the use of bacteria can be used to achieve proper yield in the experimental and also similar areas. Also, the results show that using bacteria can reduce the consumption of phosphorus chemical fertilizers.

In order to study the vegetative characteristics, yield and seed quality of canola as influenced by silicon, sulfur and Tecamin flower, an experiment was conducted in in the farmer’s condition in the Darzian, 12 km far from Marivan during the two consecutive growing seasons 2017-18 and 2018-19 in the form of spilit- split plots in a randomized complete block design with three replications. In the main plot, silicon foliar application at two levels (0 and 2 kg/ha), in the sub-plot, sulfur foliar application at three levels (0, 1 and 2 liters per hectare) and also in the sub-sub plot, foliar application of reproductive growth biostimulant of Tecamin flower at three levels (0, 1 and 2 liters per hectare) were considered. The results of combined analysis showed that stem weight under the influence of the year showed a significant difference at the level of 5%. Silicon application affected significantly the number of axillary stems, pod weight, pod length, grain weight and seed protein and Tecamin foliar application also affected significantly all studied traits such as plant height, first pod height from the ground, number of axillary stems, stem weight, pod weight, pod length, grain weight, grain yield, oil and protein seed. Also the mentioned traits except plant height, number of axillary stems and pod length affected significantly by sulfur. Based on finding, silicon (2kg/ha) and sulfur and Tecamin (2L/ha) increased the studied characters. In this study sulfur and Tecamin increased the grain yield as: 7.42 and 14.12% compared to control, respectively. Protein seed significantly increased by silicon as 0.66%. Also oil and protein seed increased by 2 litre sulfur (3.33-3.34%) and 2 litre Tecamin (1.2-1.31%). Based on the interaction effects, silicon and sulfur foliar application as 2 L/ha were increased the oil seed by 4.03%. Also seed protein increased by 5.23% in second year by silicon and sulfur and Tecamin (2L/ha). Therfore, according to the effects of the used treatments on the seed yield and quality increasing and considering the costs of preparation and foliar application, the utilization of sulfur and Tecamin flower as 2L/ha is recommended in similar climatic condition and in canola cultivation.

Awareness of the existence of specific weeds in an area can be better decided and planned about their control methods. Otherwise, applying different control methods will not have the desired effect. In this study, in order to identify and prepare maps of weed distribution in canola fields of Sorkhankalateh region of Gorgan county, 50 fields were selected and sampled based on W pattern in two stages. Then, using current formulas, frequency, relative frequency, species uniformity and biodiversity indices were calculated. We were recorded the geographical coordinates and altitude of the sampling location by a GPS, Garmin touch model for each field. The obtained information was processed using Arc GIS software (var. 10.3) and the distribution maps of all weeds in canola fields were prepared. The results showed that 41 weed species (20 species in the pre-spraying stage and 21 species in the post-spraying stage) from 14 plant families were present in surveyed fields of Sorkhankalateh region, which Poaceae, Asteraceae, Fabaceae, Brassicaceae and Polygonaceae were the most important plant family. In the pre-spraying stage, the share of annual, perennial and biennial species was 75, 15 and 10%, and in the post-spraying stage, their share was as 66.66, 23.80 and 9.52, respectively. In terms of growth form, in the pre- and post-spraying stages, 8 and 76.19% species were belonged to dicotyledonous and 20 and 23.80% were as monocotyledonous, respectively. According to the results of biodiversity indices, weeds in the post-spraying stage had more diversity than the pre-spraying stage. Also, the results related to weed distribution maps showed that most of the dominant weeds were distributed in the Eastern and southern parts of the studied region.

Determination of optimum sowing date plays an important role in crop management and achieving the higher yield. To study the effectof sowing date on seed yield of canola cultivars, a filed experiment was carried out as strip split plot block arrangement in randomized completed block design with three replications in 2017-18 and 2018-19 cropping seasons at Safiabad Agricultural and Natural Resources Research and Education Center of Dezful, Iran. Vertical factors consisted of six levels of sowing date (23rd September, 07th October, 22nd October, 06th November, 21st November  and 06th December), and horizontal factors were seven canola cultivars (Agamx, Hyola4815, Hyola50, Hyola401, Safi6, Zabol9 and Zabol13). Results showed that high temperature, due to the delay in sowing date, during the silique stage and grain filling period led to a reduction in the number of silique per plant and seed yield. In 2017-18, mean comparison of sowing date × cultivar interaction effect revealed that the highest number of siliques per plant (513.5 silique.plant-1) belonged to Zabol-13 in 23rd September sowing date , and the lowest (88.5 silique.plant -1) to Zabol13 in sowing date 06th December. In 2018-19, the highest number of siliques per plant (713.67 silique.plant-1) was counted in 22nd October sowing date and Safi6, and the lowest (126.24 silique.plant-1) belonged to Hyola401 in 06th December sowing date. The highest seed yield (3244 kg.ha-1) belonged to Agamax in 22nd October sowing date in2017-18 cropping season. Hyola50 had the highest seed yield (2888 kg.ha-1) in 7th October sowing date in 2018-19 cropping season. Seed yield stability anlysis showed that Hyola50 had the lowest mean rank and identified with thehighest seed yield and yield stability in all sowing dates (except .22nd October) followed by Agamax and Zabol9, respectively. In conclusion, 23rd September - 06th November can be recommended as optimum sowing date window for canola production in the north Khuzestan conditions in Iran.

To investigate the effect of foliar application of micronutrients and salicylic acid on seed and oil yield of canola under drought stress conditions,  a field experiment was carried out as spilt factorial plots arrangemnts in randomized complet block design in 2016-17 and 2017-18 cropping seasons in Lorestan University, Khorramabad, Iran. Experimental treatments included; irrigation at two levels: (A1) irrigation at 80% of field capacity (non- stress) and (A2) irrigation at 30% of field capacity (drought stress) assigned to main plots and foliar application of combination of iron, zinc and manganese elements at two levels: (B1) zero, and (B2) concentration of 2‰ and salicylic acid foliar application at four levels: (C1) zero, (C2) 0.5, one (C3) and (C4) 1.5 mM were randomized in sub-plots. The results showed that water deficit stress decreased total chlorophyll content (12%), Silque number per plant (20.4 silique.plant-1) and increased peroxidase enzyme activity (22%). Application of micronutrients increased chlorophyll content (13%) and carotenoids (10%). Salicylic acid foliar application with concentration of 0.5 mM had the highest seed oil content (40.9%). The highest water productivity (1.26 kg.m-3) was obtained in irrigation at 80% of the field capacity, foliar application of two per thousand concentration of iron, zinc and manganeze, and foliar application of 1.5 mM salicylic acid (A1B2C4). In 2016-17, the highest seed yield (4427 kg.ha-1) was obtained from the application of irrigation at 80% of the field capacity, foliar application of 2‰ micronutrients and foliar application of 1.5 mM salicylic acid (A1B2C4). In 2017-18, the highest seed yield (4955 kg.ha-1) was obtained irrigation at 80% of the field capacity, foliar application of 2‰ micronutrients and foliar application of one mM salicylic acid (A1B2C3). The results showed that under drought stress conditions, simultaneous application of micronutrients and salicylic acid increased seed yield and significantly increased oil yield (1449 kg.ha-1) as compared with control treatment (803 kg.ha-1). Based on the results of this experiment, foliar application of iron, zinc, and manganese micronutrients together with 1.5 mM salicylic acid improved seed and oild yield of canola under drought stress conditions.

Nitrogen fertilizer application and optimal density are important factors in increasing yield of canola. This study was carried out in order to investigate the effects of nitrogen fertilizers and plant density on some physiological characteristics, yield and yield components of Canola, as a factorial experiment in a randomized complete block design with three replications at Sheshdeh region of Fasa in 2018-2019. Nitrogen fertilizer factor in 12 levels including a1: urea (recommended) before planting and stem elongation, a2: urea (recommended) before planting, stem elongation and heading, a3: urea (recommended) in stem elongation and heading, a4: urea ( under recommended) before planting and stem elongation a5: urea (under recommended) before planting, stem elongation and heading, a6: urea (under recommended) in stem elongation and heading, a7: ammonium sulfate (recommended) before planting and stem elongation, a8: ammonium sulfate (recommended) before planting, stem elongation and heading, a9: ammonium sulfate (recommended) in stem elongation and heading, a10: ammonium sulfate ( under recommended) before planting and stem elongation a11: ammonium sulfate (under recommended) before planting, stem elongation and heading, a12: ammonium sulfate (under recommended) stemming and heading and density factor in three levels 50, 70 and 90 plants m-2.  Results showed that the effect of fertilizer on number of Raceme per subbranch and per plant was significant at 5% level and the effect of plant density on 1000 seed weight, total plant weight, seed yield and oil yield was significant. Ammonium sulfate (following fertilizer recommendation) had the highest number of Raceme per subbranch (48.6 per subbranch) and raceme per plant (73.5 per plant) in the shoot and bud stages. The highest biological and grain yield (12840 and 4258 kg.ha-1, respectively) were obtained at plant density of 50 plants.m-2. density 50 was significantly higher than 70 in terms of grain yield. Overally, the density of 50 plants.m-2 and the use of ammonium sulfate in the shoot and bud stages had the highest yield of Canola.

 Drought stress as one of the most important abiotic stress is the main limiting factor of oilseed rape cultivation in arid and semi-arid climates. Therefore, the identification of drought tolerant genotypes is the essential programs in these regions. One of the appropriate methods to identify drought tolerant genotypes is the use of stress tolerance indices. To this end, the present study was designed to detect drought tolerant among 38 winter genotypes using drought tolerance indices.

 The experiment was based on randomized complete block design (RCBD) with three replications under both normal and drought conditions during 2016 to 2017 cropping season. In the well-watered experiment, irrigation was performed in five stages, while in drought treatment, irrigation was stopped before flower initiation. The yield of genotypes under normal and drought conditions using drought tolerant indices, including; TOL, MP, GMP, HM, STI, YSI, SSI, YR, K1STI, K2STI and RDI were investigated to identify drought tolerant and susceptible genotypes.

 Analysis of variance showed a significant difference among evaluated genotypes for all drought tolerance indices. The highest coefficient of genotype variability was observed for TOL and SSI, YR and K2ST1 indices. Correlation analysis showed a significant positive correlation between Yp and TOL, SSI and YR, while a negative correlation was observed for Ys. The principal component analysis showed that the two first components covered 99.64% of all data variations. 65.36 and 34.28% of the variation were covered by the first and second components, respectively.  The first component detected tolerant genotypes, but the second component identified drought sensitive genotypes. Cluster analysis, while confirming the results of principal component analysis, classified genotypes into three categories. Cluster analysis confirmed the PCA results, which separated drought tolerant genotypes (Class 3) from sensitive genotypes (Class 1).

 Finally, this research detected five superior genotypes, including; G6, G10, G18, G23 and G33, which were the most drought tolerant genotypes and their yields were not significantly changed under normal and drought stress conditions.

The pod drop and seed losses in rapeseed is one of the most important problems in the cultivation of this plant and determining the most appropriate harvesting time can greatly prevent this problem and subsequently reduce the grain yield reduction. Thus, the present research was conducted as a split-plot in time in the form of a randomized complete block design with three replications during the crop year of 2019-2020 in the Research Station of the Rice Research Institute of Iran in Rasht. The main factor was rapeseed genotypes at 22 levels and the subfactor was harvesting time at three levels (including the amount of moisture between 30-40, 20-30, and 10-20% in the third grade of the lower stage of the original stem). The results of analysis of variance showed that in addition to the significance of yield-related traits in rapeseed lines, the interaction of lines in time was also significant, which shows the effect of harvesting time on rapeseed lines is different. In most of the lines, the highest and lowest grain yields were related to the first and second harvesting time, respectively. The highest grain yield was found for SRL-98-17 with a mean of 3662 kg ha-1. Number of siliques per line due to loss of pods decreased from the first to the third harvesting time. However, SRL98-9, SR-98-19, SRL-98-1 and SRL-98-11 had the lowest loss of grains. According to these results, it seems that the first harvesting time results in the highest grain yield, hastens the harvest of rapeseed by one week, and potentiates it as a suitable choice for inclusion in the rotation after a rice crop.

Rapeseed is one of the most important oilseeds in Iran and the world. Due to Iran's dependence on imports of oilseeds and the existence of suitable conditions for the production of this product, it is necessary to determine stable genotypes in terms of grain yield and recommend the best genotypes for different environmental groups.

In order to study the effect of genotype and environment interaction, 10 rapeseed cultivars were planted in a randomized complete block design with three replications in five regions including Birjand, Karaj, Kashmar, Sanandaj and Shiraz and evaluated for grain yield in 2018-2019.

The results of combined analysis of grain yield showed that the effect of environment, treatment and genotype × environment interaction were significant. Environment, genotype and genotype × environment interaction accounted for 74, 12 and 14% of the total variance, respectively. Among the locations, the highest grain yield was related to Karaj with an average yield of 6.51 tons per hectare. Among the studied cultivars, the highest grain yield was related to Hyola401 and Okapi cultivars at 5.54 and 5.20 t / ha, respectively. The first and second components of GGE biplot explained 88.8% and 5.9% of grain yield changes, respectively. Simultaneous study of stability and performance base Bioplot method introduced Hyola401 and Opera genotypes as stable, high-performance genotypes. Using a biplot polygon view, six superior genotypes and three mega-environments were identified. Diagrams of relationships between cultivars classified the studied genotypes into two groups. The first group included Zarfam, Likord, Sarigol, Hyola401, Opera and Okapi genotypes and the second group included Hyola308, Modena, Option500 and Modena cultivars. Hyola401 and Opera genotypes In Karaj, Birjand and Sanandaj environments, Zarfam genotype in Kashmar and Okapi genotype in Shiraz were the most desirable genotypes. The Likord genotype had general stability to all environments.

In general, it can be concluded that Hyola401 genotype is more desirable than other genotypes and also Karaj region has a higher average yield among the studied environments.

Drought is one of the most important environmental stresses and occurs for several reasons, including low rainfall, salinity, high and low temperatures, and high intensity of light. Drought stress causes changes in the physiological, morphological, biochemical, and molecular traits in plants. In Iran, many regions suffer from water stress. Moreover, rapeseed is one of the best crops for rotation with wheat. So, and the culture of rapeseed has been increasing recently in Iran. However, rapeseed often suffers from many stresses, such as salinity, cold and drought, which cause great yield loss every year. Since the rapeseed is an economical crop in Iran and drought stress is a limiting factor for crop production, this study was performed to compare some drought resistance mechanisms in sensitive and tolerent cultivars of rapeseed.

This research was designed to identify some drought resistance mechanisms in two cultivars of rapeseed. (Sensitive and tolerant) in germination (with five drought levels) and vegetative stages (zero, low, moderate and severe levels). Polyethylene glycol 6000 (PEG) was used to induced drought. Finally, pigment photosynthesis, proline content, and activity of guaiacol peroxidase was determined. The data obtained undergone a two-way analysis of variance and the mean differences were compared and tested by Duncan test using SPSS v. 2016 software from three replications. Differences at P≤0.05 were considered significant.

In the low level of drought stress, the significant difference was not observed between cultivars at the germination stage. However, the results showed that with increasing drought, germination percentage and shoot length decreased so that it reached zero at the lowest water potential, while root length increased at -0.14 MPa osmotic potential and then decreased at the lower water potential. In the second stage of experiments, the amount of photosynthetic pigments enhanced with reduction of water potential and it was more under moderate and severe stress in sensitive and tolerant cultivar, respectively. Also, the proline content increased to the level of moderate drought stress, which was significantly higher in the tolerant cultivar than the sensitive cultivar. Except for severe drought, the activity of guaiacol peroxidase enzyme was not statistically significant between other treatments and it was more in the roots of tolerant plants compared to sensitive plants. In general, due to the high amount of photosynthetic pigments and proline and guaiacol peroxidase activity in resistant cultivars, it can be suggested that increased efficiency of photosynthesis under stress as a result of more photosynthetic pigments, effective removal of ROS due to high activity of guaiacol peroxidase enzyme and higher compatibility as a result of osmotic regulation by proline accumulation, are part of the mechanisms of coping with dehydration in tolerant canola cultivars.

The results of this study showed that just germination factors could not confirm the sensitivity and resistance of rapeseed cultivars, and more experiments in the hydroponic culture medium is a better way to identify resistant cultivar.

Microorganisms that live inside plant tissues, termed endophytes, may offer benefits to their host affected to biotic and abiotic stress conditions including extreme temperatures (Card et al., 2016). Characterized endophytic strains which show no host specificity could be transferred from their original wild plant hosts into elite cultivars through different method of inoculation. Fungal endophyte of Pseudogymnoascus pannorum. is a psychotolerant fungus resistance to frosting temperature and associated with plants grown in the arctic regions. The association of a strain of Pseudogymnoascus pannorum which has been previously isolated from a wild turnip was investigated with five oilseed rape hybrids in this study (Roodi, 2019). Seeds of five oilseed rape hybrids were surface-disinfected and inoculated by immersing in spore suspension of the fungus. Seeds were then transferred to pots and placed in a glasshouse in a completely randomized block design with three replications. The colonization frequencies of brassica seedlings inoculated with fungal endophyte was assessed at two vegetative plant growth stages. This was done by plating the 15 small piece of disinfected tissue of stem of each hybrids in a Perti dish with Potato Dextrose Agar medium. Petri plates were incubated at 22˚C and checked regularly for microbial growth. The colonization tissue frequency of each hybrid calculated and data statically analysed. The penetration of fungal hyphae was also studied by a light microscope. The results from re-isolation of fungal endophyte from inoculated oilseed rape hybrids demonstrated that the fungal endophyte of Pseudogymnoascus pannorum colonized shoot tissues of all five hybrids studied and establish a close association with all oilseed rape hybrids. The analysis of variance of colonization tissue frequency showed that there is no significant difference between hybrids. The highest and lowest colonization rate was belonging to hybrid Turan and Ladoga with 19.96 and 18.81 percent respectively. The visual observation of inoculated plants showed that the endophytes does not induce any disease symptoms or change in plant growth and development of brassica plants. Control plants were not infected with the fungal endophyte. Although the origin host of the fungal endophyte was a wild turnip of Brassica rapa species, the result from inoculation indicates that this strain shows no host specificity. This is consistence with the result of another study that showed a strain of Beauveria bassiana isolated from another host can colonize other species such as oilseed rape (Vidal & Jaber, 2015). However, there was a significant difference between rates of colonization at two different growth stages. The mean colonization frequency at one and three-leaf stage was statically compared with t-student (unpaired group) witch was significantly different (99%). The mean colonization rate of hybrids was 17.77 and 20.48 percent at one and three-leaf stage respectively. Microscopic study of stem tissues also illustrated that the hyphae of fungus penetrate inside the epidermal layer of stem tissue.In this study we demonstrated that a specific strain of Pseudogymnoascus pannorum is able to colonize the areal parts of oilseed rape hybrids and establish a close association. This genus of fungus is an endophyte with psychotolerant properties that occupies plant grown in arctic regions. The results from this study can be used for further investigations on symbiosis benefits of this association especially to study the induction of resistance of oilseed rape to environmental stresses such as frosting and plant growth enhancement. Acknowledgment:This study was supported by Agricultural Research, Education and Extension Organization of Iran, Massey University and AgResearch Ltd. (Grasslands campus), Grasslanz Technology and Ellet Trust foundation, New Zealand. Keywords:Key words: Canola, seed inoculation, endophytic association, host specificityReferences:1- Card SD, Hume DE, Roodi D, McGill CR, Millner JP & Johnson RD (2015) Beneficial endophytic microorganisms of Brassica – A review. Biol Control 90: 102-112.2- Roodi D, Millner JP, McGill CR, Johnson RD & Card SD (2019) Bio-prospecting of endophytes of Brassica. PhD dessertation. Faculty of plant science, Massey University. Palmerston North. New Zealand. Pp.161.3- Vidal S & Jaber LR (2015) Entomopathogenic fungi as endophytes: plant-endophyte-herbivore interactions and prospects for use in biological control. Curr Sci 45-54.

Salinity stress is one of the most important factors limiting the growth and production of crops. To evaluate salt tolerance of canola genotypes and identification of tolerant genotypes through salinity stress tolerance indexes, a factorial experiment was conducted based on randomized complete block design with three replications at Sari University of Agricultural Sciences and Natural Resources. Factors consisted of 30 rapeseed genotypes and salinity at zero and 12 dS/m sodium chloride sources (NaCl). Based on higher values of tolerance and yield indices in normal and stress conditions, genotypes of Westona, 401Hyola, Ziho, Jef Neuf, Kunto and Alk were considered as tolerant genotypes and genotypes of skaria, Starlight, Lisandra, Burosemjanaja Sarigol, Niro1 and Niro2 were considered as sensitive genotypes. In addition, biplot analysis and cluster analysis confirmed these results. In cluster analysis, genotypes were divided into three groups. The results of this study indicate that the stress tolerance index (STI), the mean productivity (MP) and the geometric mean productivity (GMP), yield index (YI) and average harmonic index (HM) can be effective in selection of tolerant genotypes and the stress tolerance index (STI) is more effective than the other indexes.