Prevention of Autogamy and Geitonogamy in Papaya

Autogamy refers to the self-fertilization of a flower, while geitonogamy refers to the transfer of pollen from one flower to another flower on the same plant. In papaya, both autogamy and geitonogamy are prevented by different mechanisms.

Prevention of Autogamy in Papaya:

1. Dichogamy: Papaya flowers are dichogamous, which means that the male and female reproductive organs of the flower mature at different times. The male organs mature first and release pollen before the female organs become receptive. This prevents self-fertilization.

2. Self-incompatibility: Papaya flowers have a self-incompatibility mechanism that prevents self-fertilization. The stigma of the flower rejects its own pollen, which ensures that only pollen from another plant can fertilize it.

Prevention of Geitonogamy in Papaya:

1. Dioecy: Papaya plants are dioecious, which means that they have separate male and female plants. This prevents geitonogamy because pollen from a male plant cannot reach the female flowers on the same plant.

2. Pollinator attraction: Papaya flowers produce large quantities of nectar to attract pollinators, such as bees and butterflies. This ensures that pollen is transferred between different plants, rather than within the same plant.

In summary, both autogamy and geitonogamy are prevented in papaya by dichogamy, self-incompatibility, dioecy, and pollinator attraction.