Question

Given below are two statements, one is labelled as Assertion (A) and other labelled as Reason (R).
Assertion (A): False negative result will render the plant pathogen detection kit unusable
Reason (R): False negative results are due to poor sensitivity of the markers
In light of the above statements, choose the most appropriate 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:

In diagnostics, high sensitivity is crucial to avoid false negatives, which can lead to the accidental release of infected planting material.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Diagnostics and pathogen detection are essential for plant quarantine, biosafety, and disease management.
A diagnostic kit must be highly sensitive and specific to reliably detect low levels of pathogen inoculum in plant tissues.

Step 2: Detailed Explanation:
Let us evaluate both statements:
- Assertion (A) is true: A false negative occurs when a diagnostic kit fails to detect a pathogen that is actually present in the sample.
In agriculture and plant quarantine, false negatives are highly dangerous.
If infected planting materials are incorrectly cleared as healthy, it can lead to disease outbreaks and epidemics.
This makes the detection kit unreliable and practically unusable for screening.
- Reason (R) is true: False negative results typically occur because the molecular or serological markers used in the assay have poor sensitivity (low detection limit).
If the pathogen titer in the plant tissue is below the kit's detection threshold, the assay will yield a negative result despite the infection being present.
Because the low analytical sensitivity of the markers causes false negatives, which in turn makes the kit unreliable and unusable, Reason (R) is the correct explanation of Assertion (A).

Step 3: Final Answer:
Hence, the correct option is (A).