I've been thinking about the question of whether it makes any difference which fruit off a plant (tomato, pepper, etc.) is used to save seeds -- i.e., if I select a particularly nicely-formed tomato from my Pruden's Purple plant, am I more likely to get a higher percentage of nicely-formed fruit than if I use seeds from one of the extremely gnarly tomatoes? Or would there only be an advantage to growing out multiple plants and then saving seeds from a plant that had a higher percentage of the nicely-formed fruit? Does each seed in one tomato have the same genetic makeup as every other (barring "sports" of course) ? I've read that one should save seed from the "crown fruit," which is the first to develop -- how does that make a difference?
From the Seed Savers Exchange: " Cross-pollination between modern tomato varieties seldom occurs, except in potato leaf varieties which should be separated by the length of the garden. Do not save seeds from double fruits or from the first fruits of large-fruited varieties. Pick at least one ripe fruit from each of several plants. Squeeze seeds and juice into a strainer and wash, spread on a paper plate, and dry."