In vitro selection of endosulfan-tolerant strains of Brassica compestris (cv. Brown Sarson)

Endosulfan tolerant lines of mustard (Brassica campestris cv. Brown Sarson) have been developed through tissue culture methods. Cotyledonary expiants excised from eight day old in vitro grown seedlings were used for inducing callus. Fast growing friable callus was then transferred to MS medium containing (0.1-2.0 ugl(-1)) endosulfan for selection. Five alternating exposures with and without endosulfan containing medium yielded an endosulfan tolerant cell line (ETL). The plants regenerated from ETL were found to tolerate three fold higher concentrations of endosulfan. Callus induced from randomly selected endosulfan tolerant regenerated plants were also tolerant to 3.0 ugl endosulfan, thereby, suggesting that tolerance has been acquired at the gene level.Biochemical investigation revealed higher levels of total free sugar, free amino acids, protein and activity of peroxidase in the tolerant cell line.