Question

The Reniform nematode, Rotylenchulus reniformis have a unique life cycle where the egg gives rise to

• A. First stage juvenile
• B. Second stage juvenile
• C. Third stage juvenile
• D. Adult female

Hint:

For major plant-parasitic nematodes (such as root-knot, cyst, and reniform nematodes), the first molt (J1 to J2) occurs inside the egg. This means the hatching stage is always the J2.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The reniform nematode, Rotylenchulus reniformis, is a key plant-parasitic nematode with a semi-endoparasitic habit.
Its life cycle progresses from egg, through four juvenile stages (J1 to J4), to the adult stage.
Detailed Explanation:
- Inside the egg shell, the embryo develops into the first-stage juvenile (J1).
- The J1 undergoes its first molt (M1) entirely within the egg shell to become the second-stage juvenile (J2).
- As a result, the stage that hatches from the egg is the second-stage juvenile (J2).
- The hatched J2 is a free-living, non-feeding stage in the soil. It undergoes subsequent molts (J2 to J3, and J3 to J4) in the soil without feeding, eventually developing into the infective immature female or the adult male.
This pattern is common in several tylenchid nematodes, where hatching is delayed until the second juvenile stage is reached.

Step 2: Final Answer:
The egg of Rotylenchulus reniformis hatches to release the second-stage juvenile (J2).