Author Topic: Open Source F1 Hybrids  (Read 909 times)

Klaus Brugger

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Open Source F1 Hybrids
« on: 2018-12-26, 03:50:25 AM »
Hello,

I’d like to start a discussion thread on hybrid breeding. What are your thoughts on hybrids in the context of open source breeding and small freelance breeders?

I think there are three main possible advantages:
Exploiting heterosis, reaching high phenotypic uniformity in crossbreeding species, and, at least theoretically, developing useful new cultivars in a very short time by just crossing lines you already have.

On the downside, of course, there’s reduced genetic variability compared to genetically diverse open-pollinated/population cultivars. Seed sovereignty doesn’t have to be a problem: You just have to make your parent lines available.

Looking forward to reading your thoughts,
Klaus

Joseph Lofthouse

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Re: Open Source F1 Hybrids
« Reply #1 on: 2018-12-26, 09:28:22 AM »
I made a F1 hybrid sweet corn this summer, and listed it in my seed catalog. I also listed the parents of the cross, so that anyone could recreate it.

Sugary enhanced sweet corn germinates unreliably in my garden. My customers generally prefer sugary enhanced sweet corn. Therefore I made the cross with an old fashioned sweet corn as the mother, and my village's most popular sugary enhanced commercial sweet corn as the pollen donor. The seed stock has the thick seed coat, and high seed weight of the old-fashioned sweet corn, facilitating more reliable germination. 25% of the kernels on the offspring will have the sugary enhanced sweetness that my customers desire.

This sort of hybrid might be a good way to swing the days to maturity one way or the other to meet local needs, by choosing different pollen donors. I bet that an F1 hybrid would be really pretty, if the pollen donor was white kerneled only, and the mother is multi-colored.

This winter, a company that produces hybrid tomato seed is growing an F1 hybrid seed crop for me. I am intending the seeds for my own use, as a breeding project. This is part of my beautifully promiscuous self-incompatible tomato breeding project. Because the plants can't pollinate themselves, that greatly simplify the labor necessary to make F1 hybrids.
« Last Edit: 2018-12-26, 09:39:49 AM by Joseph Lofthouse »

Walt

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Re: Open Source F1 Hybrids
« Reply #2 on: 2018-12-26, 01:46:51 PM »
Nearly a century ago, Kansas State University released an open sourced silage sorghum hybrid, or rather the 2 inbreds for making the hybrid.
The 2 inbreds had different dwarfing genes, so the inbreds and F1 seed could be easily harvested with combines.  The F1 plants would be tall for making lots of silage.
It never caught on.

Early corn breeders recommended variety hybrids for commercial grain production.  Inbreeding itself doesn't give better hybrids, just uniformity, so their F1 hybrids are uniformly better or worse,  The worse are discarded, the better are mass produced and sold as seed.  Again, they never caught on.

Face it, most farmers and gardeners prefer to buy their seeds.  That doesn't mean we should stop breeding landraces, pure lines, hybrids, whatever we like.  But huge, ever-growing seed companies will be around for as far as I can see into the future.

William S.

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Re: Open Source F1 Hybrids
« Reply #3 on: 2018-12-26, 02:47:43 PM »


This winter, a company that produces hybrid tomato seed is growing an F1 hybrid seed crop for me. I am intending the seeds for my own use, as a breeding project. This is part of my beautifully promiscuous self-incompatible tomato breeding project. Because the plants can't pollinate themselves, that greatly simplify the labor necessary to make F1 hybrids.

In the typical situation with tomatoes the F1 isn't really usually that exciting and it''s the F2 we are after. I'm guessing your situation isn't typical?  In my imagination I am thinking you are using the help to make a mass F1 between two promising groups that are each segregating?
Western Montana garden, glacial lake Missoula sediment lacustrian clay mollisoil sometimes with added sand in places. Zone 6A

Joseph Lofthouse

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Re: Open Source F1 Hybrids
« Reply #4 on: 2018-12-26, 04:15:50 PM »

I realize that the internet meme is that tomatoes don't experience inbreeding depression, but  when carefully measured, F1 tomatoes are about 50% more productive than the inbred parents, and 10% earlier. Which to me, goes a long ways towards explaining why hybrid tomatoes are so popular. One of the things I am looking forward to in my beautifully promiscuous self-incompatible tomato project, is that every seed will be a unique F1 hybrid in every generation, which aught to go a long ways towards reducing inbreeding depression.

We are making the F1 between an inbred domestic mother, and a segregating F3 hybrid clan. I expect it to be an excellent tomato in it's own right, and think that a hybrid like that could lead to some large tomatoes with a unique flavor profile.  Might be worth recreating for seed sales. We are also promiscuously pollinating the best of the best of the F3 clan within themselves.





Klaus Brugger

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Re: Open Source F1 Hybrids
« Reply #5 on: 2018-12-29, 02:57:19 AM »
Thank you all for your very interesting answers.
I think that unfortunately F1 hybrids have a bad name with many people interested in "heirloom" and open source cultivars. At least where I live, some explanatory work has to be done.
I'm interested in hybrid breeding especially in Cucurbita. On the one hand for uniform fruit quality and on the other hand for interspecific hybrids that you cannot just dehybridize easily.

Joseph Lofthouse

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Re: Open Source F1 Hybrids
« Reply #6 on: 2018-12-29, 10:04:44 AM »

One of my favorite F1 hybrids, is between Hubbard and Banana Squash. The taste is fabulous. Texture is mid-way between the parents. The cross was one of the contributors to my current landrace.

I have certainly had lots of practice getting people to try things that can't be bought in the grocery store. I bet it would be fairly easy to market "Heirloom Hybrids", or "Landrace Hybrids".

Making F1 hybrids using Cytoplasmic Male sterility is certainly within the reach of small scale seed producers. They could even be open source, if the parent lines were shared freely. I choose to not use that technique on my farm, because I don't like growing broken plants.

Klaus Brugger

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Re: Open Source F1 Hybrids
« Reply #7 on: 2018-12-31, 02:44:51 AM »
"Heiloom Hybrids", I like that.

... I don't like growing broken plants.

Haha, that's why I don't get the same joy from "double flowers" in Dahlia etc. anymore ...

reed

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Re: Open Source F1 Hybrids
« Reply #8 on: 2018-12-31, 04:05:40 AM »
For a small scale gardener like me I don't see any value at all to hybrids. I'm perfectly happy to include them in my landrace crops and to dehybridize them but F1 hybrids themselves, have no permanent place in my garden.

I definitely don't want any CMS but even something easy to cross like corn. Say for example I find an F1 I really like. I know all seed doesn't have to be grown the same year but to grow that F1 every year I also have to grow both of it's parents in isolation, and I have to grow both of it's parents to cross for the F1 seed. So I'v got four different patches, two isolated, one to cross and finally the one I want.  No good at all if your goal is small scale, largely closed system, sustainability.

If my goal was to market seeds I might have a very different perspective. Even if my customers knew the parent lines and could if they wanted to do the cross themselves it isn't likely that many would.

Interspecific hybrids are a whole different critter. To me in a way, they are the only true hybrids but still I won't be making or buying them over and over again. They have to go ahead and dehybridize, start making seeds and blend in or their out.





« Last Edit: 2018-12-31, 05:37:25 AM by reed »

Joseph Lofthouse

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Re: Open Source F1 Hybrids
« Reply #9 on: 2018-12-31, 08:51:02 AM »
Haha, that's why I don't get the same joy from "double flowers" in Dahlia etc. anymore ...
Me too. I have selected my dahlias for single flowers, so that they can get pollinated.




Joseph Lofthouse

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Re: Open Source F1 Hybrids
« Reply #10 on: 2018-12-31, 08:56:44 AM »

One year, I made an F1 hybrid squash with natural pollination. I had the female growing nearby to the squash patch, and I kept the male blossoms picked, so that all the pollen came from the patch that I intended as the father. It worked very well.

Many types of seeds don't need to be grown every year. The seed remains viable for many years. So an F1 hybrid, and the parent types, would only have to be regenerated perhaps once a decade.

Klaus Brugger

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Re: Open Source F1 Hybrids
« Reply #11 on: 2018-12-31, 09:09:00 AM »
So an F1 hybrid, and the parent types, would only have to be regenerated perhaps once a decade.

That's what I think too. Especially with crops that have a high seed multiplication ratio, I don't know if space has to be that big of a problem. I do think hybrids in addition to op cultivars can have a value for small-scale gardeners without being too difficult to maintain.

Even if my customers knew the parent lines and could if they wanted to do the cross themselves it isn't likely that many would.

That sounds reasonable, but how many home gardeners really do multiply op cultivars, let alone in a way that doesn't let the cultivar deteriorate? Yes, I'm being polemic, but I think it's an issue with non-hybrid cultivars. Home gardeners like to buy high-quality seeds from experts and that's not necessarily a bad thing (I do so, too). But if an expert (professional or amateur) wants to multiply a cultivar, it's possible with "heirloom hybrids" ...

Edit: PS: Beautiful dahlias!

reed

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Re: Open Source F1 Hybrids
« Reply #12 on: 2018-12-31, 09:20:12 AM »
I love those dahlias, mine I got from you Joseph, grow beautifully and make by far the largest tubers I have ever seen. I grew them in 2017 and left most of the tubers in the ground to test for hardiness. I have had dahlias overwinter before but they did not. Didn't plant any in 2018 but will be putting them in again next year.

I intend to make a few different F1 corn crossings this coming year. I'm going on to blend them into a new OP.  I'll take notice in the F1 grow outs. If something extra nice shows up in the F1 I'll just let others know which parents produced it.

Carol Deppe

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Re: Open Source F1 Hybrids
« Reply #13 on: 2018-12-31, 08:15:11 PM »
Hello,

I’d like to start a discussion thread on hybrid breeding. What are your thoughts on hybrids in the context of open source breeding and small freelance breeders?

I think there are three main possible advantages:
Exploiting heterosis, reaching high phenotypic uniformity in crossbreeding species, and, at least theoretically, developing useful new cultivars in a very short time by just crossing lines you already have.

On the downside, of course, there’s reduced genetic variability compared to genetically diverse open-pollinated/population cultivars. Seed sovereignty doesn’t have to be a problem: You just have to make your parent lines available.

Looking forward to reading your thoughts,
Klaus
The most standard commercial pattern is to cross two inbred lines to get an F1 hybrid where the plants are genetically as uniform as possible. However, if we interplant two op varieties that aren't inbred, emasculate one, and save seed from it, we can get an F1 hybrid where the plants are not genetically identical, and actually retain all the genetic variability in both parent varieties. Interestingly, such an F1 is usually more uniform phenotypically than the two parents, although not as uniform as if we crossed two inbreds. This is useful because there can be more resilience associated with the more genetically variable F1. And it may be uniform enough so that under our conditions, (with variable land, tilling, etc), it is just as phenotypically uniform as the F1 between inbreds. And we often times have good op varieties we are maintaining, but not inbred lines.

You can interplant two short adjacent rows of different squash op varieties, for example, and keep the male buds picked off one variety initially. Then mark the fruits on that variety that have set during the emasculation period (and quit emasculating) That way you can get seed that is F1 between the op varieties and representing several plants. (Bees, by the way, usually visit flowers multiple times, not just once.) It might be necessary to keep vines of the variety to be emasculated pruned to one or two during the emasculation period so you aren't overwhelmed with male buds needing to be found and eliminated.

It would be useful if we started experimenting with making our own hybrids and report on the forum the results.


Klaus Brugger

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Re: Open Source F1 Hybrids
« Reply #14 on: 2019-01-03, 11:51:55 AM »
[...] Interestingly, such an F1 is usually more uniform phenotypically than the two parents, although not as uniform as if we crossed two inbreds. [...]

That's very interesting and encouraging! I've been thinking some time about pros and cons of hybrids between inbred lines and "population variety hybrids". And I had the idea that the latter would probably completely lack a significant uniformity advantage.

[...] If something extra nice shows up in the F1 I'll just let others know which parents produced it. [...]
[...] It would be useful if we started experimenting with making our own hybrids and report on the forum the results. [...]

That sounds like a good idea. I have two interspecific squash F1s for 2019 and in 2018 I had a rather nice hybrid between the two domesticated subspecies of C. pepo which I will probably plant again this season.