For union between stock and scion in grafting which one is the first to occur (a) formation of callus (b) production of plasmodesmata (c) differentiation of new vascular tissues (d) regeneration of cortex and epidermis.
Option A Grafting is a techinque in which cambium bearing shoot (scion = graft) of one plant is joined to cambium bearing stump (root system = stock) of a related plant through different unions like tongue grafting, wedge grafting etc. In grafting union between stock and scion produces undifferentiated mass of cells called callus. Therefore, for union between stock and scion in grafting, first to occur is the formation of callus. Callus is more or less corky secondary tissue developed lay woody plants over a wound. It is derived from cambium
