Phytotoxic effects of safflower yellow exposure on seed germination and early seedling growth of canola (Brassica napus L.)

The aim of current investigation was to determine phytotoxic effects of safflower dye (safflower yellow) on seed germination and early seedling growth of canola (brassica napus l.) cv. rainbow. safflower yellow was extracted in autoclaved distilled water and was applied at various concentrations (0.312%,0.625%,1.25%,2.5% and 5%) to canola seeds in petri dishes under axenic conditions. phenolics content was detected in dye solutions and was maximum (53 mg gallic acid/g extract) in 5% dye solution. the growth rate of canola was decreased with the increase of safflower dye concentration (p<0.05). maximum inhibition in the activity of enzyme lipase in germinating seeds,germination (%),root and shoot length,root and shoot weight was exhibited by 5% dye solution. in response to the application of safflower dye,canola seedlings accumulated endogenous phenolics. relative water content and photosynthetic pigments of seedling were reduced to a maximum level by 5% and 2.5% dye solutions. it was inferred that safflower dye exhibited phytotoxic effects at higher concentration on canola. the findings of the current investigation will help in safe disposal of safflower dye found in industrial effluents. © 2014,pakistan botanical society. all rights reserved.