What part is typically removed to prevent natural pollination in plant breeding?

In plant breeding, the part that is typically removed to prevent natural pollination is the anther sac. The anthers are the structures that produce pollen, which is vital for the process of pollination. By removing the anther, it prevents pollen from being released and fertilizing the ovules in the same flower or another flower on the same plant, thus hindering natural pollination.

This practice is crucial for controlled pollination, allowing breeders to manage the genetic contribution from specific plants, leading to desired traits in offspring. This approach is fundamental in creating hybrids and developing new varieties that exhibit improved traits such as disease resistance, yield, or other characteristics beneficial for agriculture.

In contrast, the stigma is involved in capturing pollen, the pistil forms the female reproductive part of the flower, and the ovary contains the ovules that will develop into seeds after fertilization. Each of these structures plays a different role in the reproductive process, but it is specifically the anthers that need to be removed to achieve control over cross-pollination in breeding programs.