Dichogamy:
Dichogamy refers to the phenomenon where the maturation of the female reproductive structures (stigma) and the male reproductive structures (anthers) of a flower occurs at different times. This temporal separation of the maturation of these structures within the same flower is an important mechanism to prevent self-fertilization and promote outcrossing in plants.

Reasons for Dichogamy:
Dichogamy can occur in different forms, including protandry (male phase first) and protogyny (female phase first). It is a common strategy in many plant species and offers several advantages:

1. Prevent Self-Fertilization: By ensuring that the stigma and anthers of a flower are not receptive or producing pollen simultaneously, dichogamy helps to avoid self-fertilization. This is important for maintaining genetic diversity within a population.

2. Promote Outcrossing: By having the stigma and anthers mature at different times, dichogamy promotes outcrossing, which involves the transfer of pollen between different individuals of the same species. Outcrossing helps to increase genetic variation and adaptability within a population.

3. Avoid Pollen Wastage: In dichogamous flowers, the anthers usually release pollen before the stigma becomes receptive. This prevents self-pollination and reduces the wastage of pollen on flowers that are not yet ready for fertilization.

Types of Dichogamy:
1. Protandry: In protandrous flowers, the anthers mature first and release pollen before the stigma becomes receptive. This ensures that the flower is not self-pollinated and promotes cross-pollination. Examples of protandrous plants include sunflowers, primroses, and corn.

2. Protogyny: In protogynous flowers, the stigma becomes receptive before the anthers release pollen. This sequential maturation prevents self-pollination and increases the likelihood of cross-pollination. Common examples of protogynous plants include cucumbers, squashes, and hollyhocks.

Importance of Dichogamy:
Dichogamy is an important reproductive strategy that enhances genetic diversity in plant populations. By preventing self-fertilization, dichogamy promotes outcrossing and reduces the risk of inbreeding depression. It also allows for the exchange of genetic material between different individuals, facilitating adaptation to changing environmental conditions.

Overall, the temporal separation of stigma and anther maturation in dichogamous flowers is an adaptive mechanism that ensures efficient pollination, genetic diversity, and reproductive success in plant populations.

Dichogamy- It is the condition when the anther and stigma mature at different times. Either anthers dehisce before the stigma becomes receptive (called protandry) or stigma becomes receptive before anthers dehisce (called protogyny