**Types of Self-Pollination**:
– Hermaphrodite and monoecious species can self-pollinate.
– 80% of flowering plants are hermaphroditic, while 5% are monoecious.
– Dioecious plants are unisexual.
– Some plants have mechanisms to avoid self-fertilization.
– Examples of self-pollinating plants include orchids, sunflowers, and dandelions.
**Advantages and Disadvantages of Self-Pollination**:
– Advantages include maintaining stable traits, less wastage of pollen, and preservation of parental characters.
– Disadvantages involve limited adaptation, inbreeding depression, and potential genetic defects.
– Self-pollination does not require external carriers or attractants.
– Many flowers have mechanisms to prevent self-pollination.
**Mixed Mating Systems**:
– Around 42% of flowering plants exhibit a mixed mating system.
– Plants can produce self-pollinated, out-crossed, or mixed progeny types.
– Mixed mating systems help in genetic diversity and adaptation to changing environments.
– Some plants have both open, potentially out-crossed, and closed, obligately self-pollinated flowers.
**Evolutionary Significance and Examples of Self-Pollination**:
– Evolutionary shift to self-fertilization is common in plants.
– About 10-15% of flowering plants are predominantly self-fertilizing.
– Examples of self-pollinating species include orchids, Caulokaempferia coenobialis, Capsella rubella, and Arabidopsis thaliana.
– Self-pollination can persist over many generations and be an evolutionary adaptation for certain species.
**Mechanisms and Research Studies on Self-Pollination**:
– Orchids exhibit unique self-fertilization strategies.
– Anther-stigma interactions facilitate self-pollination.
– Specific floral structures promote auto-pollination.
– Studies explore the effect of pollen source on progeny and the evolutionary consequences of selfing in plant species.
Self-pollination is a form of pollination in which pollen from the same plant arrives at the stigma of a flower (in flowering plants) or at the ovule (in gymnosperms). There are two types of self-pollination: in autogamy, pollen is transferred to the stigma of the same flower; in geitonogamy, pollen is transferred from the anther of one flower to the stigma of another flower on the same flowering plant, or from microsporangium to ovule within a single (monoecious) gymnosperm. Some plants have mechanisms that ensure autogamy, such as flowers that do not open (cleistogamy), or stamens that move to come into contact with the stigma. The term selfing that is often used as a synonym, is not limited to self-pollination, but also applies to other type of self-fertilization.
