Impact of cadmium toxicity on leaf area, stomatal frequency, stomatal index and pigment content in mungbean seedlings

Effect of different concentrations of CdSo(4) (10(-4)M, 5 x 10(-4)M and 10( -3)M) on leaf area, stomatal frequency, stomatal index and pigment content in 6 days old mungbean seedlings was studied under laboratory conditions. E xcept at 10(-4) M CdSO4, leaf area decreased with an increase in the concen tration of CdSo(4). Stomatal frequency on the leaf surface increased at 5 x 10(-4)M and 10(-3)M CdSO4 in comparison to untreated control. However, rev erse was the case for stomatal index. Chlorophyll-a, chlorophyll-b, total c hlorophyll, and chlorophyll a/b ratio were increased at 10(-4)M CdSO4 and d ecreased thereafter with an increase in the concentration of Cd2+. Possible reasons for the stimulatory effect at low concentrations and inhibitory ef fect with higher concentrations are discussed.