I've got a tetraploid hybrid "Inspiration" growing in my yard (well, not at this moment because of the winter dormancy, but you get the idea). I've noticed that it sets fruit readily, unlike it's non-tetraploid sibling, "Incense." So this past summer, I hand-pollinated the flowers every chance I got with pollen from my Texas native incarnata. It produced about 10 solid fruit that ripened by October, which are more bulbous and solid-feeling than that of Incense. I marked them all for identification (unnecessary, really, since they're fatter and more pumpkin-shaped than maypop fruit) and put them away to deal with at a later date.

Last night I took out the fruit. All the incarnata fruit I'd shelved had dried nicely inside, leaving a firm but tacky skin covering each seed, a consistency not unlike a paper-thin fruit roll-up. I've found this keeps the seeds from drying out, and preserves their viability for early spring germination. So then I cut open the Inspiration fruit, and guess what? They were completely FULL of juicy, pulpy arils. Absolutely no dessication at all. Wow. That's five months of sitting there, with little or no water loss. The rind of the fruits is quite firm and unyielding as well, and could stand up to quite a bit of abuse. All the arils had large, ripe seeds in them. I have no idea if any are viable--tetraploids aren't supposed to be able to cross with diploid species, but there've been rumors of triploid crosses here and there--but I'm going to plant up a bunch and see if any sprout. I tried it with a few seeds last year and got nothing, so it may simply be sterile. But it's worth a shot.

In any event, the surprising shelf life of the fruit surprised me. I've read several places that commercial passion fruit's market potential is hindered by its relatively fragile nature. If someone could develop a palatable hybrid through crosses with Inspiration that maintained this tough rind (I didn't hazard a taste of the arils. For one, they'd been sitting there 5 months. For two, it's didn't smell all that appealing. Not rotted, but rather... tart? Acidic? Nothing I wanted to taste) it could be a real boon to commercial passion fruit farmers.