Question

Match List I with List II
List I:
A. Coconut lethal yellowing
B. Cotton wilt
C. Citrus canker
D. Bitter gourd yellow mosaic
List II:
I. Psyllid
II. Whitefly
III. Leafhopper
IV. Grasshopper
Choose the correct answer from the options given below:

• A. A-III, B-IV, C-II, D-I
• B. A-I, B-III, C-IV, D-II
• C. A-III, B-IV, C-I, D-II
• D. A-II, B-I, C-III, D-IV

Hint:

To remember this match: Coconut lethal yellowing is transmitted by leafhoppers, Citrus canker spread is facilitated by psyllids, and yellow mosaic viruses are transmitted by whiteflies.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Plant pathogens can be transmitted by insect vectors either biologically (where the pathogen replicates or undergoes development within the vector) or mechanically (via contaminated mouthparts or feet).

Step 2: Detailed Explanation:
Let us analyze each disease-vector association:
1. Coconut lethal yellowing (A): This disease is caused by a phytoplasma that affects palm trees.
It is transmitted by the cixiid planthopper/leafhopper, Haplaxius crudus, which is a leafhopper (III).
Therefore, A matches with III.
2. Cotton wilt (B): Fungal spores of Fusarium or Verticillium can be spread mechanically.
Chewing pests like grasshoppers can transport these spores on their bodies or transfer them via feeding wounds.
Therefore, B matches with the grasshopper (IV).
3. Citrus canker (C): This bacterial disease is caused by Xanthomonas citri.
While it is primarily spread by wind and rain, its spread is also facilitated by piercing-sucking insect vectors like the citrus psyllid, which is a psyllid (I).
Therefore, C matches with I.
4. Bitter gourd yellow mosaic (D): This viral disease affects cucurbits.
Like other geminiviruses, it is transmitted by the whitefly, Bemisia tabaci, which is a whitefly (II).
Therefore, D matches with II.

Step 3: Final Answer:
Combining these individual matches yields the sequence: A-III, B-IV, C-I, D-II.