Photosynthesis By Isolated Chloroplasts of Cyamopsis Tetragonoloba (L) Taub., As Influenced By B Vitamins

Indirect action of vitamins at higher concentrations ranging from 50 to 200 mgl⁻¹ on isolated chloroplasts (in vivo) i.e., chloroplasts isolated from the leaves after receiving foliar spray, caused stimulation of photo-synthetic carbon fixation while direct action of vitamins (in vitro) above 5.0 mg 1⁻¹ concentration (i.e., isolated chloroplasts ftom control plants incubated in vitamin solutions) resulted in diminished carbon fixation. All the vitamins used in the present study viz., thiamine, riboflavin, niacin, pyridoxine, pantothenic acid and folic acid significantly increased photo-synthetic carbon fixation by isolated chloroplasts (in vivo). Vitamin concentration upto 5 mg 1⁻¹ were found to be optimal in enhancing carbon fixation by isolated chloroplasts in vitro.