Question

Virus transmission by whitefly is
(A) Non-persistent type
(B) Non-propagative- type
(C) Persistent and circulative type
(D) Semi-persistent type
Choose the correct answer from the options given below:

• (A) and (B) only
• (A) and (C) only
• (B) and (C) only
• (C) only

Hint:

Remember that begomoviruses (the primary whitefly-transmitted viruses) travel through the insect's body (circulative) and persist inside it (persistent), but do not replicate within the insect's cells (non-propagative).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Whiteflies, particularly Bemisia tabaci, are vectors for plant viruses in the genera Begomovirus, Crinivirus, Carlavirus, and Ipomovirus.
The mode of transmission describes how the virus interacts with and travels through the vector.
Detailed Explanation:
The most economically important viruses transmitted by whiteflies are Begomoviruses (family Geminiviridae).
Begomoviruses are transmitted by Bemisia tabaci in a persistent, circulative, and non-propagative manner:
- Persistent (C): The insect remains capable of transmitting the virus for several weeks, often for the remainder of its adult life.
- Circulative (C): The virus is ingested, passes through the gut wall into the hemolymph, and accumulates in the salivary glands before being injected into a new plant.
- Non-propagative (B): The virus does not replicate or multiply inside the cells of the whitefly vector.
While whiteflies can transmit some other viruses (like criniviruses) in a semi-persistent manner, the primary, classic mode of transmission associated with whitefly-vectored begomoviruses is persistent-circulative (C) and non-propagative (B).

Step 2: Final Answer:
The mode of virus transmission by whiteflies is characterized as non-propagative, persistent, and circulative, corresponding to statements (B) and (C) only (option 3).