Interspecies squash hybrids

[William S.]

Spent some time looking at Josephs squash ID guide. http://garden.lofthouse.com/how-to-identify-squash.phtml

This year I grew intentionally maxima squash, pepo squash, moschata squash and two interspecies hybrids from Joseph Mospermia and Maximoss. Though I used much of my maximoss seed last year, a few grew again this year, possibly because I mixed some in with the mospermia last year then never got it planted and last year's grew at least well enough to contaminate my maxima a little.

I also grew a Thai cross moschata from Mike a hybrid Moschata from Territorial called Autumn's Choice, and a old land race called Rancho Marques. All with some mixta/agrosperma characteristics.

I think that the thai cross squash from Mike might be an example of ancient mospermia. Also the Rancho Marques but it didn't produce a fruit for me. Also the Autumn's choice I think may in fact be a more modern Mospermia type. It's leaves look maple like and the fruits have that interesting pattern of yellow and green bands.  My actual mospermia and maximoss look like they should. The Mospermia tend toward moschata peducles. I see one small squash that looks just like a tetsukabuto. Though mostly I think that my maxima grex has just a little maximoss contamination now. Which is fine. There is one mospermia fruit that looks like Autumn's choice.

[Diane Whitehead]

I guess maximoss is a hybrid between maxima and moschata.

But what is mospermia?

[William S.]

Joseph's name for his strain of Moschata x Agrosperma (mixta).

[Ferdzy]

We ended up being a bit short on zucchini seed this year, so we planted some old ones we had saved in 2013, from Lebanese White Bush (pepo). What we got was not LWB, not too surprisingly. We got a couple of vines that ran absolutely rampant. The squash were not nice as zucchini, as they grew fast and filled up with seeds almost instantly. One (the smooth skinned one) is probably just some random pepo cross of no distinction. It already has a couple of bad spots on it.

The other one, though; that one looks like a cross between LWB and Tennessee Sweet Potato (a mixta/argyrosperma). Haven't eaten any of them as mature squash yet. They seem amazingly solid and I think I may have to take an axe to them to break them open. Dunno what I think of them; unless they are marvelous (unlikely) I don't think we will grow them out again. If they have viable seed I assume they will have crossed with other pepo squashes grown this year.

[Diane Whitehead]

Well, I guess you could eat the seeds so the plants' efforts won't have been completely unappreciated.

[Ferdzy]

We usually do, unless they have very tough skins. Which, given how tough the outsides are, might be possible. I'll post again once we've cracked one open.

[Ferdzy]

So! I cut open one of my supposedly crossed squashes this afternoon. I am more convinced than ever that it is a cross between a pepo and an argyrosperma. The skin was very hard - it took my largest knife and a fair bit of pressure to get it open. Seeds look plentiful, plump and lovely. Flesh was pale, and extremely bland when tasted raw. It took a looooong time to cook; 1 1/2 hours at 400°F. and the texture was still quite firm, almost crunchy; the flavour was still very mild but actually quite pleasant.

I can find little information about pepo-argyrosperma crosses, although I did find a comment that they were "rare". It also appears, the fine apparent quality of the seeds notwithstanding, that they are likely to be infertile. I have popped 8 of them into a damp coffee filter in a baggie by the fireplace; I'll see what, if anything, happens.

I took a picture of the insides, and also I want back and looked at a photo taken of the squash bed in the summer. In it, you can clearly see that the plant from which these squash came has the typical argyrosperma silvery markings, even though it was saved from a White Lebanese (pepo) zucchini.

Edit: no, I'm wrong about the leaves. That's actually a pepo (zucchini) - I was thinking I was looking at this bed from 180° different spot. The leaves from this one are in fact very large and shallowly lobed, dark green and fairly low, and behind the second post. This was taken in mid July and they had not yet taken over the entire bed as they had by the end of the season.

[Ferdzy]

Okay! I put 8 seeds in a damp coffee filter etc, on the 25th and today at least 2 have sprouted. So obviously some good fertility there! Is anyone interested in some of these seeds? They are almost certainly (pepo White Bush Lebanese x argyrosperma Tennessee Sweet Potato) x pepo unknown (multiple?). Apparently this doesn't happen very often. We may grow out a few, but I think, at least in the next (f2) generation they are likely to be rather large plants.

[Ferdzy]

Well, they all germinated beautifully but I guess no one is particularly interested. 

I'll keep a few seeds but not too sure what I'll do with them.

[Chance]

Ferdzy, this is super interesting.  Really great progress could be made for a more resistant zucchini like cultivar.  When I looked at cucurbita genetic relationships a while ago, one thing that stood out is that pepo has a huge amount of diversity, with genetic distance of some cultivars greater that between even the other species of cucurbita.  Some of these cultivars are closer to argyrosperma.  I’d love to grow some of these but it would have to wait till 2021.  Looking forward to updates.

[Steph S]

I'm not much of a squash eater and I don't find them easy or reliable to grow here, so I just have to admire them from a distance. 

[Ferdzy]

Ferdzy, this is super interesting.  Really great progress could be made for a more resistant zucchini like cultivar.  When I looked at cucurbita genetic relationships a while ago, one thing that stood out is that pepo has a huge amount of diversity, with genetic distance of some cultivars greater that between even the other species of cucurbita.  Some of these cultivars are closer to argyrosperma.  I’d love to grow some of these but it would have to wait till 2021.  Looking forward to updates.

Chance, I will cheerfully save some seeds for you until then. I believe cucurbit seeds keep very well. Unfortunately, I know these will take a lot of space and a lot of time to turn into something valuable, but my impression from a quick look around is that that the pepo-argyrosperma cross really is quite unusual.

[Ferdzy]

I'm not much of a squash eater and I don't find them easy or reliable to grow here, so I just have to admire them from a distance. 

And even for people who do like squash, and can grow them, it's a lot of space for something that's more of a lottery ticket than actual food. I do get it. That's why I won't be growing them out myself, beyond maybe one or two plants... which really won't tell me much, I don't think.

[Steph S]

It's interesting that the flesh is pale colored like the Pepo parent.   That alone is pretty unusual in any kind of winter squash.   I guess in an F1 cross that means white is dominant in the flesh color, or is the color a QTL and will produce many shades?   Growouts are always fun.

[William S.]

I grew out some of Joseph's Mospermia interspecies or agrosperma this year and have yet to eat one. They are pretty squash. Do well in a mixed vegetable dish where they absorb flavors from more flavorful vegetables such as beets and apples or perhaps any situation where they might absorb some meat juices like a beef roast. Definitely low on my eating priority winter squash list. I think buttercups, then other maxima, then moschata, then pepos and agrosperma last. I'll probably save seeds from those then skip a year or two with them. I got a packet of Tetsukobuto F1 seeds for my birthday. I think I may plant half of them with buttercups and half with moschata. I think I may have messed up my seed saving of Joseph's maximoss. Still have one small one I'm pretty sure is it. May have dispersed some of the rest to family. They may have contaminated mospermia by design, but won't know for awhile if I skip years on that.

I really like Josephs strain of buttercups. May have to get another packet from him. Wouldn't mind if they contamInate everything else. Might plant less squash next year. Or just straight up.more buttercup.I think my priorities next year will be the Tetsukobuto packet, buttercup, and Autumn's Choice F2 potentially pollinated by a mix of thai cross and Josephs moschata.

One of the things that is a little sad to me is not having endless space for new projects. Also having to choose which of a number of deserving projects get attention in a given year.