Itsepölytystä

Itsepölytystä, also known as self-pollination, is a process in which pollen from the anther of a flower is transferred to the stigma of the same flower or another flower on the same plant. This reproductive mechanism is common in many plant species, particularly in self-pollinating varieties of crops like wheat, barley, and tomatoes. It can also occur in some flowering ornamental plants.

The outcome of itsepölytystä is that the resulting offspring are genetically similar to the parent plant. This can lead to a high degree of homozygosity, meaning that the plant carries two identical alleles for many genes. In agricultural settings, itsepölytystä is often desirable as it helps maintain desirable traits in crop varieties, ensuring consistency in yield and quality from one generation to the next. It also simplifies breeding programs as there is no need to control cross-pollination.

However, itsepölytystä can also have drawbacks. A lack of genetic diversity can make populations more vulnerable to diseases and environmental changes, as there is less variation for advantageous traits to emerge. Inbreeding depression, a reduction in fitness due to increased homozygosity, can also occur over successive generations. Many plants have evolved mechanisms to promote cross-pollination, such as self-incompatibility, which prevents pollen from fertilizing ovules of the same flower or genetically similar plants.