EFFECT OF SULPHUR DIOXIDE ON PLANT CHLOROPHYLL ON THE FAMILY OF BRASSICACEAE

The effect of SO2 on chlorophyll in (Brassica juncea [L.] Czern.and Coss.cv.Pusa Bold; Raphanus sativus L.cv. Mino Early Long White).In exposed seedlings SO2 concentration ranging (653, 1306, 2612&3918 µg m-3 SO2), resulted in a sharp decrease in total chlorophyll content. Both chlorophyll a and chlorophyll b got reduced and declined following the exposure of SO2. This decrease could be due to disturbance in chloroplast ultra structure and because of conversion of chlorophyll into phaeophytin upon exposure to SO2. After spraying of calcium hydroxide the yield in C+ SO2 exposed set was higher than the set of plant exposed to SO2 alone. Maximum reductions were noticed at 3918 µg m-3 of SO2. The breakdown of chlorophyll molecules by SO2 as measured by loss of Mg++ andtotal chlorophyll.