I don’t remember much from when I was reading about Musa breeding, but I think M. velutina would probably be essential in any cold-hardy edible banana program. It’s one of the few (perhaps only?) cold hardy bananas that will flower and fruit in a single growing season. With other bananas, you have to have some way of overwintering the pseudo-stem, which drastically increases the challenge since p-stems can be quite difficult to get through a winter.
Juniper Level Botanic garden have M. velutina in zone 7b/8a and get fruit on them, I think usually by September.
I think that’s an Achilles heal unfortunately. No matter how tasty a new banana might be, it’s going to get compared against the commercial ones, which are A) dirt cheap and B) seedless. Someone breeding cold hardy bananas is gonna have to pull off cold hardy, early ripening, good flavor, and seedlessness. That’s a tall order. I’ll stick to citrus for now, not that cold hardy citrus is any easier haha
This is where I think new fruits that don’t have built in expectations, or hardy versions of less highly-selected fruits, is in some ways easier, even though you then have the hurdle of getting people to try stuff they are unfamiliar with. A cold hardy guava can have seeds and be sour, and people will still accept it, and a cold hardy Eugenia can be anything so long as it is tasty, since basically no one has any priors on what they expect them to be like. A cold hardy avocado, though, has to be rich, creamy, oily, etc. or people just aren’t going to care for it. Same problem with bananas.
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