Question

Match List-I with List-II 

List-I (Disease)		List-II (Vector/Causal Organism)
A	Tomato spotted wilt	I	Brevicoryne brassicae
B	Tomato yellow leaf curl	II	Hyaloperonospora brassicae
C	Cauliflower mosaic	III	Frankliniella occidentalis
D	Downy mildew	IV	Bemisia tabaci

Choose the correct answer from the options given below:

• (A) - (I), (B) - (II), (C) - (III), (D) - (IV)
• (A) - (II), (B) - (I), (C) - (IV), (D) - (III)
• (A) - (III), (B) - (IV), (C) - (I), (D) - (II)
• (A) - (I), (B) - (II), (C) - (IV), (D) - (III)

Hint:

To simplify this match: - Thrips (Frankliniella) are the exclusive vectors for tospoviruses like Tomato Spotted Wilt.
- Whiteflies (Bemisia) are the exclusive vectors for begomoviruses like Tomato Yellow Leaf Curl.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Plant pathogens (viruses and oomycetes) are transmitted by specific vectors or are associated with causative organisms.
Detailed Explanation:
Let us match the plant diseases in List I with their corresponding vectors or causative organisms in List II:
- (A) Tomato spotted wilt: This is caused by Tomato Spotted Wilt Virus (TSWV), which is transmitted by thrips.
A primary vector is the western flower thrips, {Frankliniella occidentalis (III).
- (B) Tomato yellow leaf curl: This is caused by Tomato Yellow Leaf Curl Virus (TYLCV), a begomovirus transmitted by the sweetpotato whitefly, {Bemisia tabaci (IV).
- (C) Cauliflower mosaic: This is caused by Cauliflower Mosaic Virus (CaMV), which is transmitted in a non-persistent manner by aphids.
A common vector is the cabbage aphid, {Brevicoryne brassicae (I).
- (D) Downy mildew: This is a plant disease caused by oomycete pathogens.
A major causative pathogen of downy mildew in brassicas is {Hyloperonospora brassicae (II) (formerly Peronospora parasitica).
This yields the match: (A) - (III), (B) - (IV), (C) - (I), (D) - (II).

Step 2: Final Answer:
The correct matching sequence corresponds to option (3).