The Effect of Photoperiod on Steroidal Sapogenins and other Constituents in Dioscorea deltoidea Wall

Dioscorea vines were cultured under different light periods(viz. 18 h light and 6 h darkness and vice versa), for 3 monthsand the effects on the composition and percentage of steroidalsapogenins present, at different stages of growth, were studied. Total sapogenins from different parts of the vine were estimatedat different times and it was found that the percentage of theseincreased in leaves and tubers during growth as also did theamount of phenolic components. New information regarding the nodal ganglion (nodal plexus)is brought to light, namely that this complex glandular tissueappears to be a seat of bio-chemical synthesis. Nodal gangliahave been analysed at different growth phases of the vine andthe amounts of different constituents recorded.