Effect of Zinc on Rooting and Callus Induced by Auxin in Pumpkin

We have found that auxin (2, 4-D)-induced roots were further promoted by the addition of zinc in rice which is monocotyledonous plant. Therefore, we examined whether a similar phenomenon would occur in dicotyledonous plant such as pumpkin. Similarly, a change from root formation to callus induction was observed in pumpkin plant. However, the change to callus in pumpkin plant was induced at lower auxin concentration than that of the rice plant. The callus formation was also suppressed as that of rice plant with the addition of zinc. In rice, new roots were formed when callus formation was suppressed with zinc, but there was no new root formation in the pumpkin plant.