Response of spring Canola (Brassica napus L.) genotypes to water deficit stress

ABSTRACT: Water deficit stress considered as one of the most important limiting factors for canola (Brassica napus L.) growth and productivity in Iran. To evaluate the effect of water deficit stress on yield and some of traits related to yield of spring canola genotypes, this experiment carried out as factorial based on randomized complete block design with 3 replications. Three levels of water deficit stress as first factor (75mm, 100mm and 125mm evaporation from class A pan), and second factor was including 9 spring canola genotypes. Analysis of variation revealed significant difference among the various canola genotypes and levels of water deficit stress for all traits. In addition to, interaction between levels of water deficit stress and genotypes was significant for number of pod and harvest index. Water deficit reduce all traits. Hyola308 and SW5001 under control and stress conditions had the highest grain yield and yield components and Sarigol had lowest grain yield. The decrease of all traits except number of grains per pod at the I2 was more than I3. Stress susceptibility index for Hyola308 and SW5001 at I2 to I3 was 0.74 and 0.78 respectively, and Sarigol showed 1.39 at I2 to I3, which it can implies that Sarigol is more sensitive than other genotypes to water stress. Cluster analysis classified the genotypes into three groups i.e., tolerant, susceptible and semi-tolerant or semi-sensitive to drought conditions. Therefore they are recommended to be used as parents for improvement of drought tolerance in other cultivars.