Phytotoxicity of River Chenab sediments: In vitro morphological and biochemical response of Brassica napus L.

• Phytotoxic evaluation of River Chenab Pakistan sediments was performed in B. napus seedlings.
• A significant variation of seed germination, plant length, weight, and water content was observed.
• Remarkable raise in phytochemical analysis (MDA, Phenolics, flavonoids, cholorophyll, caratenoids) from control was also examined.
• The increase of antioxidative enzyme activities (SOD, POD and protease) were also observed in seedling exposed to sediments.
• Phytotoxicity evaluation is easy, robust and reliable method to assess sediments contamination.

River Chenab is one of the major sources of water for irrigation of agriculture fields in Punjab, Pakistan. The present investigation was conducted to appraise the effect of river Chenab sediments on growth; morphological and biochemical prospects of in vitro grown Brassica napus seedling. A total 19 residue samples collected from different sites of River Chenab were evaluated. The sediments extracts, in most of the cases, significantly influenced on final germination, rate of germination and mean period of final germination of B. napus seedlings in comparison with controls. Reduction in root length was observed as compared with shoot length. Decrease in relative dry weight of seedlings ranging from 45% to 64% was also examined. Biochemical analysis revealed that the sediments extracts tend to increase in total protein and total phenolic contents in B. napus plants while variation in MDA and flavonoid contents were observed as compared with control. Increase in chlorophyll a & b and carotenoid contents were also observed in plants germinated in the presence of sediments extracts except sample 4. The enzymes (POD, SOD and protease); responsible to mitigate hazardous effects of sediment contamination; were found elevated in the seedlings. Phytotoxic evaluations of sediments demonstrate that it is consistent and practical tool for assessing quality of sediment. However, increased activities of antioxidants; enzymes and proteins favor the adaptation or tolerance to contamination by the seedlings.