Question

Arrange the following stages in successful graft union formation:
A. Intermingling of callus cells,
B. Production of callus parenchyma cells,
C. Formation of vascular tissues,
D. Establishment of cambial continuity, E. Differentiation of callus cells into cambial cells. Choose the correct answer from the options given below:

• A. A, B, C, D, E
• B. C, D, A, B, E
• C. B, A, E, D, C
• D. D, B, C, A, E

Hint:

Successful graft union requires callus formation, cambial continuity and vascular connection.

Answer 1

The Correct Option is C

Concept:
Grafting becomes successful only when stock and scion establish cambial and vascular connection.

Step 1: Callus production.
First, callus parenchyma cells are produced at the cut surfaces of stock and scion. \[ B=\text{Production of callus parenchyma cells} \]

Step 2: Intermingling of callus.
Callus cells of stock and scion intermix with each other. \[ A=\text{Intermingling of callus cells} \]

Step 3: Cambial differentiation.
Some callus cells differentiate into cambial cells. \[ E=\text{Differentiation into cambial cells} \]

Step 4: Cambial continuity.
The cambium of stock and scion becomes continuous. \[ D=\text{Establishment of cambial continuity} \]

Step 5: Vascular tissue formation.
Finally, new xylem and phloem tissues are formed. \[ C=\text{Formation of vascular tissues} \] Thus, the correct sequence is: \[ B,A,E,D,C \] \[ \therefore \text{Correct Answer is (C)} \]