Gabe15

So my post stating that triploids do not have viable pollen is wrong, that was almost 10 years ago and I've learned a lot since then! While it's true that many do not have viable pollen, some do, and a given cultivars ploidy level shouldn't be used to determine it's inherent fertility, either on the female or male side.

Now, that being said, for a simple breeding project I would recommend to avoid using anything with a B-genome at all, as it complicates things a great matter because you have to deal with endogenous BSV (Banana streak virus) inheritance, and there is a tendency for B-containing hybrids to express this later on. There are ways that have been devised to work around this issue, but they are far more complex than what is feasible for a hobby breeding project.

As for transferring parthenocarpy, it is not so simple as a 50/50 chance. It is not a single-gene controlled trait, there at least 3 genes known, and so the chance of any one gene being passed on might be 50%, but the chance of all 3 being passed on to the same seedling is far less (with simple math ignoring other factors it would be closer to 12%), as they are independently sorted. When breeding parthenocarpic to non-parthenocarpic plants, the resulting progeny can have a range of incomplete parthenocarpy if present at all due to only containing some of the genes. The dynamics of how this affects different combinations of varieties is complex, as it greatly depends on which plants you are using, and when using exotic wild species, I would hazard to guess it's an uphill battle as it is less likely those genes are hiding out already in the wild plants, as they are for some wild M. acuminata specimens.

The ploidy levels of resulting progeny from wild x edible crosses can be all over the board, and ultimately are not very important, whats more important is parthenocarpy in a vigorous specimen. There are often hybrid seedlings produced that grow weakly for a time and ultimately end up dying for no apparent reason, and often these are of higher ploidy level than is viable. 2x, 3x and 4x are all capable of being produced and of being viable. 5x, 6x and 7x seedling can also result but generally do not thrive.

However, for all practical purposes, just focus on making crosses with whatever is flowering and see if you get seed, and don't worry too much about the complexities. If you get seed, plant it and see that happens. When working with a small number of plants, the biggest constraint is just having anything flowering at the right time to perform any cross attempt at all, so start there.

One piece of technical advice to start would be to focus on pollinating the wild species with edible pollen if you can. In this way, you will maximize the amount of potential seed you can get as they are all highly female fertile, and if there is any male fertility on the edible variety it would be put to best use on a highly fertile female (i.e., a wild plant). In the reverse sense, using wild pollen on an edible female parent, you may get seed, but most are not very fertile if at all, and the ones that are fertile still are not as fertile as a wild specimen.

Another would be to do everything in the morning as early as you can, at or soon after sunrise. This is when the plants are most fertile and you will have a higher chance of getting seed. Collect male flowers, and immediately pollinate the female flowers. Do not wait until later in the day, or collect flowers the day before for use the next day unless that is the only way you have a chance at making at cross.

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Growing bananas in Colorado, Washington, Hawaii since 2004. Commercial banana farmer, 200+ varieties.