These Australian farmers accidentally grew huge avocados | Landline
The most famous avocado variety in the world is 'Hass' and it was also a chance seedling. There are still fruits in the world that were not specifically bred, but just came up from a seed no one was paying attention to at the time.
IMO, it would be worth planting more and more seedlings to see what comes up but the price of land is at such a premium that breeding programs are constantly cutting back.
