In which plant are both autogamy and geitonogamy prevented?

In the context of plant reproduction, preventing both autogamy (self-fertilization) and geitonogamy (fertilization between different flowers on the same plant) is significant for enhancing genetic diversity. In the case of papaya, it exhibits a unique reproductive system where it has distinct male and female flowers on separate plants. This dioecious nature of papaya means that only female plants produce fruits, and thus, male plants cannot provide pollen for self-fertilization or fertilization between the flowers of the same plant. This effectively eliminates the possibilities of both autogamy and geitonogamy, fostering cross-pollination and increasing genetic variation.

In contrast, plants like tomato, peach, and mango typically have mechanisms allowing for self-fertilization or fertilization between different flowers on the same plant or contain both male and female reproductive structures, which facilitates these processes. Thus, papaya stands out for its definitive reproductive strategy that prevents both forms of self-fertilization, promoting genetic diversity through reliance on cross-pollination.