Variety Esteghlal is a facultative rapeseed which was obtained with name of Glolal from Swedish Research Institute, Svalof in 1990. This variety is in group of double zero improved varieties that erucic acid in its oil and glucosinolate in its oil-free meal are less than 2% and 30 µ mol g-1 of dry matter, respectively. Preliminary evaluation of this variety along with other rapeseed varieties began at Karaj, Orumieh and Sari Research Stations in 1990/91 cropping season and simultaneously multiplication of its seed initiated in isolated fields. This variety was further avaluated in yield trial at Karaj, Sari, Gorgan, Moghan, Orumieh, Kermanshah and Hamadan Research Stations. However because of frost hazard in cold areas, its cultivation was recommended in areas with mild winters such as Mazandaran, Gorgan and Moghan. Characteristics of the variety are presented in Table 1 (in Farsi text, Page 126). Planting date of this variety in Karaj, Kermanshah, Orumieh and Hamadan was in middle of September, and in Sari, Gorgan and Moghan in middle of October. This variety has moderate tolerance to Sclerotinia disease.

Initially the seeds of this open pollinated variety was received from the University of G6ttingen with the name Cobra in 1990. The adaptability and yield potential of the variety were investigated in preliminary and yield trial experiments under Karaj and Gorgan climatic conditions untill1995. The optimum sowing dates in Karaj and Gorgan regions were the last week of September and second week of October respectively. The cv. Talaye produced average of 2916 kg/ha and 1202 kg/ha seed and oil yields respectively during the year 1990-1994. This yield was a little lower than the cv. Azargol but superier to other varieties and was, therefore, recommended for growing in moderate cold regions as an alternate to cv. Azargol. The average seed and oil yield of this cv. under rainfed conditions of Gorgan region were 2146 kg/ha and 903 kg/ha respectively (Table 1, in Farsi text) superior to other varities and the check "O" cv. Belinda (Raeisi, 1994, 1998). Athough this variety was initetly recommended for Gorgan region, but its widespread use by farmers proved its adaptability for moderate cold regions. This cv. was grown over 100/000ha area during 1998-1999 and showed relative tolerance to Sclerotinia and Alternaria diseases. The Erusic acid of this variety was less than 2% and Glucosinolate content of its meal was less than 30 µ mol g-1 of dry matter (Ahmadi et al., 1996).

Evaluation of rapeseed and mustard adaptability is important in relation with the increasing demand for edible oil in Iran and lack of suitable cultivars for cold drylands. Randomized block designs can reduce experimental errors caused by spatial variability between blocks excluding intra-block variability. Control of spatial variability is an analysis that investigates the variance structure of each trial and uses an appropriate structure for estimation of effects in the trial. In this research, adaptation of 15 genotypes of spring type rapeseed and mustard were studied during three years in the cold drylands using spatial analysis. Results showed that, the randomized complete block design with first order auto-correlated errors along rows was the best model in the second year and the randomized complete block design with first order auto-correlated errors along rows and columns was the most effective model in accounting for spatial variability in the first and third year. There was not any evidence for fixed trend in this experiment. Based on the selected models, the best linear unbiased estimates for all genotypes were calculated. Stability analysis on estimated means showed that mustard genotypes Bard-1 and Sel-2 had the highest stability in this experiment.

To detennine number and effects of genes that control erucic acid in rapeseed BRASSICA NAPUS, two zero erucic acid cultivars were crossed with four cultivars containing various levels of erucic acid content (4.56% to 46.5%) including reciprocals. The erucic acid content of F1"s and their reciprocals was intennediate of parents indicating embryonic control of erucic acid and absence of maternal effect in inheritance of erucic acid in B. NAPUS. Erucic acid content of F2 seeds segregated in to 5 classes <2%, 2-16%, 16-32%, 32-44%, and >44% with a ratio of 1: 4: 6: 4: 1. Backcrosses seeds (BC1) derived from the F1× (zero erucic acid parents), segregated into three classes (<2%, 2-16% and 16-32% erucic acid) with a ratio of 1: 2: 1. On the other hand, backcross seeds (BC2) derived from F1× (high erucic acid parent) segregated into three classes (16-32%, 32-44% and >44% erucic acid) with a ratio of 1: 2: 1. The segregation patterns in F2 and BC1 indicated that erucic acid content in B. NAPUS was governed by two independent genes interacting in an additive manner. Pooled data analysis also conformed above results. Contributing of alleles of genes was not same. Alleles E1 and E2 in this study were equal to Ea and Eb that reported already.

Meiotic study was performed in 11 BRASSICA NAPUS cultivars considering chiasma frequency and distribution, chromosome pairing, as well as the occurrence of B-chromosomes and their effects on chiasma frequency. Such cytogenetic pairing, along with agronomic characteristics, may be used in planning hybridization among the B. NAPUS cultivars. All the cultivars studied possessed n=19 chromosome number (4x) and showed a deviant course of prophase-I meiosis with a synezetic knot and post pachytene diffuse stage. Chromosome stickiness occurred in most of the cultivars from early prophase to late telophase-II leading to the formation of laggard chromosomes and micronuclei. The cultivars studied differed significantly in chiasma frequency and distribution as well as bivalent formation, indicating their genomic differences. Cluster analysis and ordination based on principal components analysis grouped those cultivars showing meiotic similarities. Some of the cultivars showed the occurrence of B-chromosomes.

Turnip mosaic virus (TuMV), Cauliflower mosaic virus (CaMV) and Beet western yellow virus (BWYV) are considered as the most important viruses of canola, worldwide. In order to determine the distribution of these viruses in Golestan province, samples from three important canola growing areas of the province were collected during 2008 and 2009. The randomly collected samples were tested for the presence of TuMV, CaMV and BWYV through DAS-ELISA. The results revealed that canola field infection levels in 2008 with TuMV, CaMV and BWYV were at 4.5%, 2.5% and 6%, respectively. Canola field infection in 2009 with TuMV, CaMV and BWYV was at the levels of 8.33%, 1.66% and 6.33%, respectively. Data analysis showed that virus factor was significant for 2008 whereas region was the factor significant for year 2009. Furthermore, BWYV infection was confirmed through RT-PCR. It is to be mentioned that this is the first report of TuMV, CaMV and BWYV on canola in Golestan province.

Canola (BRASSICA NAPUS.L) cultivation has increased because of high percent oil and quality at different climate of Iran recently. Determination of water requirement is necessary for crop cultivation in arid region. This research was carried as randomized block desingn with 3 replications with four treatments including of I1=50 I2=75, I3=100 and I4=125 evaporation rate (mm) from pan (Class A) at Arak station.Grain yield, 1000-grain wieght, oil yield, dry matter weight, height plant, pod per plant, grain per pod and water use efficiency was mesaeured. Effect of irrigation was significant on grain yield and yield components, but interaction effect of irrigation and year was significant on pod per plant only. A difference in grain yield was affected from pod per plant and grain per pod. Statistical analysis showed that I1and I4were maximum and minimum amounts respectively, at all of variable. I1 treatment has significant effect on grain yield, height plant and grain per pod. I1and I2 had not significant differences on oil yield, pod per plant and WUE. Conclusionly I2 treatment recommend for similary Arak claimatic condition.

Rapeseed is one of the most important oil plants in the world, which due to the increase in world population and improving living standards, should increase the production and consumption of oil of this plant. It is a plant that is cultivated both in winter and spring. The use of drought tolerance indices can help us identify drought tolerant genotypes. To determine drought tolerance indices, a study was carried out with 16 autumn rapeseed genotypes. The experiment was performed on a randomized complete block design with three replications under rainfed and irrigation condition. Drought tolerance indices including MP, GMP TOL, STI and SSI were calculated using grain yield data. Measurement of cell membrane stability (CMS) using polyethylene glycol (PEG) was used as a drought tolerance test. The results of analysis of variance showed a significant difference for all indices. Stress tolerance index (STI) was the best index to identify tolerant genotypes in both stress and non-stress conditions. Estimation of STI from the average of genotypes showed that Dante (1. 22) genotype has the highest value. The results of analysis of variance for CMS showed a significant difference between genotypes at the 1% level of probability and the highest value (65. 52) was for ARC5 genotype and the lowest (32. 08) was for SLM046 genotype. There were a significant and strong correlation between STI, MP and GMP with CMS, as a result, cell membrane stability can be introduced as a fast and inexpensive method to identify drought tolerant genotypes. Based on STI, MP, GMP, CMS and grain yield indices in both stress and non-stress conditions, cluster analysis was performed, and genotypes were divided into 4 groups.

A greenhouse experiment was conducted to evaluate the competitive effects of different densities of wild mustard as against rapeseed. The experiment was performed in a randomized complete block design with four replications using replacement series in which wild mustard and rapeseed were respectively planted in different ratios of 4:0, 3:1, 2:2, 1:3 and 0:4 plants per pot. Results indicated that the maximum height, number of siliques per plant, silique length and number of seeds per silique in rapeseed vs. the maximum height, silique length and number of seeds per silique in wild mustard were obtained in their monoculture states. Overall evaluation of relative yield showed that both species were exploiting the resources in different ways or even somehow benefiting each other. Relative crowding coefficient of rapeseed as against wild mustard in the 3:1 treatment was greater than that in the other plant ratio treatments. Competition indices revealed that rapeseed benefited from a more competitive ability than wild mustard.