The experiment was conducted to investigate drought stress simulated by polyethylene glycol (PEG) at four osmotic levels of -0.6, -0.8, -1.0, and -1.2 MPa on germination and early seedling growth of 15 genotypes of Canola (Brassica napus L.). Canola, a crucial oilseed crop, faces challenges in establishment under drought conditions, necessitating the identification of drought-resistant genotypes. Key parameters, including Germination Rate (GR), Germination Percentage (GP), Shoot Length (SL), Root Length (RL), Mean Germination Time (MGT), Shoot Elongation Rate (SER), Root-To-Shoot Ratio (RSR), Seedling Vigor Index (SVI) and Root Elongation rate (RER), investigated very precisely. The results indicated a significant interaction between the drought condition and genotype for all parameters studied and the interaction effect of genotype under drought conditions. The overall values of SVI, GR, SL, RL, GP, RER, and SER in the comprehensive analysis were reduced by 90%, 91%, 95.4%, 87%, 98%, 95.5%, and 91%, respectively. There was an increase of 94% for MGT and 51% for RSR compared to non-stressed conditions. Based on the results of PCA, RL, GP, and RER, the drought-tolerant genotypes were the most different, which shows that the studied genotypes reacted differently to four levels of water stress. Genotypes 3, 11, and 13 displayed superior drought tolerance, reflected in higher GP, RL, and RER, making them suitable candidates for cultivation in arid regions. These findings underscore the potential of drought-resilient Canola varieties to enhance crop productivity in water-limited environments, suggesting further field studies to confirm their applicability under real-world conditions.
M. Amiri (Fri,) studied this question.