Evaluation of Salt Tolerance in Some Canola (Brassica napus L.( Genotypes under Normal and Salt Stress Conditions

Salinity is one of the most important factors limiting the growth and production of plants around the world. Identification of tolerant cultivars and improving plant tolerance is the most effective method for increasing yield. In order to evaluate the relationship between agronomic and biochemical traits of canola and grouping of canola genotypes in salinity conditions, an experiment was conducted at Sari Agricultural Sciences and Natural Resources University. The experiment was a factorial based on randomized complete block design with three replications. Factors included of 30 canola genotypes and two levels of salinity (0 and 12 ds /m-1). The evaluated traits include: height, the number of branches per plant, number of capsules per plant, capsule length, number of seeds per capsule, 1000-grain weight, dry weight of plant, leaf and seed sulfur, sodium / potassium ratio, chlorophyll content a and b, carotenoid content, percentage of oil, percentage of protein, Biological yield, harvest index and grain yield per plant. Genotypes in both conditions without salt stress and salinity stress showed significant differences for all traits. The effect of salinity and interaction between genotype and salinity were also significant on the above traits. The 30 genotypes of canola were classified by cluster analysis of Ward method into three separate groups in both conditions, without salt stress and salinity stress. The results of mean comparison showed that in the salinity conditions genotypes (28, 26,27,5, 2 and 24) showed the least and The genotypes (3, 22, 3, 6, 7, 16, 20, 21 and 30) showed the highest traits,such as, yield, harvest index, capsule length, number of seeds per capsule and 1000-seed weight. As a result, genotypes of the first group are introduced as sensitive and genotypes of the second group are introduced as tolerated. Factor analysis and biplots had a great similarity to the cluster analysis. According to the results, Salinity tolerant genotypes, can be used for future Plans of plant breeding.