For a successful graft, the adhesion between stock and scion is a must. Which one of the following is the earliest event towards a good graft

Options

A. Production of plasmodesmata in the cells at the interface of stock and scion
B. Coordinated differentiation of vascular tissue between the stock and scion
C. Regeneration of cortex and epidermis over the union of stock and scion
D. Production of callus tissue between the cells of stock and scion

Answer

B, D

Explanation

Vascular cambium is a thin tissue located between bark. Its cells are meristematic that is they are capable of dividing and perm new cells. For a successful graft union it is essential that the cambium of the scion be placed in lose contact with the cambium of the root stock.
Callus is term applied to the mass of parenchyma cells that develop form and around wounded plant tissues. It occurs at the junction of graft union arising from living cells of both stock and scion. Refer in Book.