This is the chimera in plant.
Chimera is the result of a natural genetic mutation in plants. In this condition, some cells lose the ability to produce chlorophyll — the green pigment essential for photosynthesis. This causes certain parts of the leaf to appear white or pale yellow.
Is it a disease?
No. Chimera is not caused by any disease, virus, or fungus. It does not spread to other plants and typically has little to no impact on plant growth or yield.