self pollination is better or cross pollination and why?

Answer 1

Neither one is "better," because it depends on the circumstances. For example, in a stable environment, self pollination is more effective because self pollination does not cause as much genetic variation as cross pollination, which is like the saying "if it ain't broke, don't fix it." If the plant is successful with the genotype that it has, why change it with cross pollination? On the other hand, in a volatile environment, cross pollination is beneficial because it provides genetic variation, which is needed to adapt to the changing environment.

Answer 2

Well, you also have to think of it from the *grower's* point of view if you're thinking of commercial plants.

Some plants don't self-pollinate, so you have to plant different types of, say, trees in an orchard and then bring in hives of bees to pollinate. Pollination depends not only on the plants, but also on the pollinating process.

If you all of a sudden run out of pollinators or there are few plants of a certain species in an area...you might not get much reproduction with cross-pollination. Cross-pollination relies on diversity, and unfortunately, humans have been awfully bad about squashing diversity in a whole lotta habitats.

They both have their benefits, but self-pollination doesn't fix the fact that humans have destroyed many pollination processes and plants have died out because of it.

Answer 3

The question is not which is BETTER, but more like why do some plants utilize self-pollenation rather than cross-pollenation? And no one can answer that question. One can only study the different plants and their pollenation process to arrive at insights why that plant is one way and not the other.

Are self-pollinating plants like tomato, self-pollenating to insure that the pollen is pure? This is a result of evolutionary genetic selection where the tomato plant reached a point, that for its best interests, devised a method to guard against X-pollenation.

Whereas X-pollenation process plants evolved so that the gene pool would always be open to first comers fitting the species basic identity. The identity is important so that a cross between oaks and marigolds don't happen.

Answer 4

Like others have said, one is not better than the other BUT in some situations one system may be better suited and desirable to achieve results.