Question

Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A) : Grafting is the union of a root system with a shoot system
Reason (R) : It combines different cultivars into a composite plant having special characteristic.
In light of the above statements, choose the correct answer from the options given below.

• A. Both (A) and (R) are true and (R) is the correct explanation of (A).
• B. Both (A) and (R) are true but (R) is NOT the correct explanation of (A).
• C. (A) is true but (R) is false.
• D. (A) is false but (R) is true.

Hint:

When evaluating Assertion-Reason questions, check if both statements are independently true first. Then, read them with “because” in between to see if the second statement explains the first.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Grafting is a widely used vegetative propagation technique in horticulture, especially for woody fruit trees and ornamentals.
It involves joining vascular tissues of two distinct plant parts so they grow as a single composite plant.
The upper part of the graft combination is called the scion, which develops into the shoot system.
The lower part is the rootstock (or stock), which provides the root system.

Step 2: Detailed Explanation:
Assertion (A) is true:
Anatomically and structurally, grafting represents the union of a root system (provided by the rootstock) with a shoot system (provided by the scion).
This physical union is established through callus formation from the cambial tissues of both parts, followed by vascular differentiation to form continuous xylem and phloem connections.
Reason (R) is also true:
Grafting allows the breeder or grower to combine different cultivars with distinct genetic backgrounds into a single composite plant.
This combination yields special, desirable characteristics.
For example, grafting a high-quality dessert apple cultivar (scion) onto a dwarfing, pest-resistant rootstock (like M9) results in a compact, early-fruiting, and disease-resistant tree.
However, Reason (R) is not the anatomical explanation for Assertion (A).
The definition of grafting as the union of a root and shoot system is based on its physical and structural nature.
The fact that it combines cultivars for special characteristics describes the commercial utility and agronomic purpose of grafting.
It does not explain the physical mechanism or structural definition of the graft union itself.
Therefore, both statements are correct, but the Reason is not the direct explanation of the Assertion.

Step 3: Final Answer:
Hence, the correct option is (B): Both (A) and (R) are true but (R) is not the correct explanation of (A).