Question

Given below are two statements :
Statement (I) : Pathological wilt is usually irreversible leading to the death of plants.
Statement (II) : Physiogical wilt too is reversible prior to the permanent wilting point.
In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both Statement (I) and Statement (II) are correct.
• B. Both Statement (I) and Statement (II) are incorrect.
• C. Statement (I) is correct but Statement (II) is incorrect.
• D. Statement (I) is incorrect but Statement (II) is correct.

Hint:

To distinguish between wilting types in the field:
- Physiological wilt affects the entire field uniformly during hot dry afternoons, and plants recover overnight when transpiration rates drop.
- Pathological wilt affects individual plants or patches scattered across the field, and the plants do not recover overnight because their xylem vessels are permanently blocked.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Wilting is the loss of turgidity in plant tissues, causing leaves and stems to droop.
It can be caused by physical water scarcity in the soil (physiological wilt) or by pathogens blocking the plant's water-transporting xylem vessels (pathological wilt).

Step 2: Detailed Explanation:
Let us evaluate both statements individually:
Statement (I): "Pathological wilt is usually irreversible leading to the death of plants."
This statement is correct.
Pathological wilt is caused by vascular pathogens (such as *Fusarium*, *Verticillium*, or *Ralstonia*) colonizing the xylem vessels.
These pathogens multiply rapidly, producing physical blockages made of fungal mycelia, bacterial cells, and gel-like extracellular polysaccharides (EPS).
Because this physical blockage permanently cuts off the plant's water-transport system, the plant cannot absorb water even if the soil is wet, making pathological wilt irreversible and leading to the plant's death.
Statement (II): "Physiological wilt too is reversible prior to the permanent wilting point."
This statement is correct.
Physiological wilt occurs when the rate of transpiration from the leaves exceeds the rate of water absorption by the roots, typically due to dry soil conditions.
During the early stages (temporary wilting), the plant will recover its turgidity and stand upright again once soil moisture is restored by watering or rain.
However, if the soil dries out beyond the "permanent wilting point" (typically $-15\text{ bars}$ of soil water potential), the soil holds onto the remaining water too tightly for roots to absorb it, making the wilting irreversible.
Both statements are correct.

Step 3: Final Answer:
Both Statement (I) and Statement (II) are correct.
This corresponds to Option (A).