There are no scientific studies on cross-pollination in mirlliton varieties, so we can’t speak with any certainty about the chances of cross-pollination. Mirlitons are self-pollinating plants and are primarily pollinated by bees. Honey bees are systematic foragers; they will focus on one plant until they have collected all the nectar. That means they are less likely to carry pollen from another plant, thus reducing the risk of cross-pollination.
Because of this, generally, you can grow two different varieties with little risk of cross-pollination. If you grow only one variety at a time, you will have even less risk. But if you want to ensure that the offspring of a plant will be true-to-type, there is a simple way to do that: controlled pollination.
Using controlled pollination will guarantee that the specific fruit you picked from your vine will grow the same variety. Click here to see how to do it.