Question

Which part of the tobacco plant is infected by Meloidogyne incognita ?

• A. Leaf
• B. Stem
• C. Root
• D. Flower

Answer 1

The Correct Option is C

 The question asks which part of the tobacco plant is infected by Meloidogyne incognita, commonly known as the root-knot nematode. To answer this, we need to understand both the biology of the Meloidogyne incognita and its interaction with plant hosts.

Detailed Explanation:

• Root-Knot Nematodes: Meloidogyne incognita is a species of plant-parasitic nematodes which are known to infect the roots of plants. They are called root-knot nematodes because they induce the formation of galls or "knots" on the roots of their host plants.
• Infection Process: The nematode larvae penetrate the roots of the host plant and establish feeding sites, causing cells to enlarge and divide, resulting in root galls. These galls disrupt the normal uptake of water and nutrients by the plant.

Justification of the Correct Answer:

• Root: As explained, Meloidogyne incognita specifically infects the roots of plants, causing root galls. These galls are detrimental to the plant's ability to absorb nutrients and water, eventually affecting its overall growth and yield.
• Incorrect Options:
  • Leaf: The nematode does not directly affect the leaves. Any symptoms on the leaves are typically secondary, resulting from root dysfunction.
  • Stem: Similarly, stems are not directly infected, though plant health could deteriorate due to root infection.
  • Flower: There is no direct infestation of flowers by Meloidogyne incognita.

Conclusion: Based on the biological interaction between Meloidogyne incognita and tobacco plants, the roots are the infected part. Thus, the correct answer is Root.