Which part of gynoecium determines the compatible nature of pollen ?

Stigma

The stigma is part of the gynoecium (female reproductive structure) that plays a crucial role in determining the compatible nature of pollen. The stigma is located at the top of the style, which connects the stigma to the ovary.

When pollen grains land on the stigma, they need to be compatible with the reproductive structures of the pistil for successful pollination to occur. The stigma has various adaptations to facilitate this compatibility determination. These adaptations include surface characteristics, such as texture, shape, and chemical composition, which can attract or repel specific types of pollen.

The stigma has specific recognition mechanisms that allow it to recognize and accept compatible pollen grains while rejecting incompatible ones. This recognition process is essential for achieving successful fertilization and ensuring the compatibility between the pollen and the female reproductive organs.

In summary, the stigma is the part of the gynoecium that determines the compatible nature of pollen by recognizing and accepting compatible pollen grains while rejecting incompatible ones.

 The other parts of the gynoecium, the style, filament, and ovary, do not play a role in determining the compatible nature of pollen. The style is the long, slender stalk that connects the stigma to the ovary. The filament is the stalk that supports the anther. The ovary is the swollen base of the pistil that contains the ovules.