Question

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R
Assertion A : Foliar plant pathogen produce pigmented and colored spores
Reason R : The dark pigmentation helps the pathogens to adapt on foliar parts to withstand high radiations
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:

Think of melanin in fungal spores like sunscreen for humans.
Dark pigments = Survival under the sun.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question explores the survival strategies of airborne (foliar) plant pathogens and the evolutionary significance of spore pigmentation (like melanin).

Step 2: Detailed Explanation:

• Assertion Analysis: Many pathogens that infect leaves (foliar pathogens) produce dark-colored spores. Examples include Alternaria (black spores), Ulocladium, and various rust fungi (orange/dark teliospores). Thus, Assertion A is True.

• Reason Analysis: Spores on leaf surfaces are exposed to intense direct sunlight. UV radiation is harmful as it can damage DNA. Melanin and other pigments absorb and dissipate this harmful radiation, protecting the internal cell organelles. This adaptation is crucial for the spores to remain viable until they can germinate and infect. Thus, Reason R is True.

• Relationship: The need for UV protection (Reason) is the primary evolutionary driver for why these pathogens produce pigmented spores (Assertion).
Final Answer:
Both statements are correct, and the Reason provides a scientifically sound explanation for the Assertion.