Breeding varietal suggestions

[Dominic J]

Well, darn it. I've been looking at tomatoes more and more, and it's looking like it's not enough to breed hops, watermelons, japanese quinces, apples, and honey bees, but I'm going to have to give a go to tomatoes as well. Just can't help myself.

But on to the subject matter, I'm looking for suggestions on what to acquire to help me with my crosses.

My target would be a cherry tomato, yellow-fleshed, indeterminate, dwarf, with Ph-2+Ph-3 late blight resistance (and ideally as many disease resistances as possible). And if such a thing exists, cold tolerance, but my searches haven't yielded me anything conclusive on that yet.

I've got a few late-blight resistant varieties: Mountain Magic, Jasper, Defiant, Plum Regal. Some open-pollinated (like 'Mémé de Beauce', 'Canabec Super', and probably some others), some rootstocks ('Estamino').

I don't have dwarves nor yellow-fleshed tomatoes as far as I'm aware. I'm thinking of maybe getting Yellow Canary?

Is there a good page somewhere to read on breeding tomatoes, and how the major traits like fruit size, growth habit, fruit flesh color and such interact? Which are recessive and to what, which are additive, etc.

I'm thinking of doing a big melting pot of Mountain Magic, Jasper, Mémé de Beauce, Estamino, and Yellow Canary, though crossing just Jasper to Yellow Canary could probably pretty much get me what I want, though Mountain Magic seems to have a much more robust disease resistance package than Jasper does. Though I also read that all of these were heterozygous on the resistance alleles, though, so many I should pick up another variety like Iron Lady instead? Though that one's a big red tomato.

[William S.]

I think Lizzano, Iron Lady, and Skykomish might be worthwhile.

[Dominic J]

Any supplier sends Lizzano to Canada? The one I found doesn't. It does sound like a perfect base.

[William S.]

I don't know but if I ever need to immigrate to Canada because of climate change I sure hope they let me across the border with my whole seed collection.

Two yellow cherry tomatoes that are short season and taste good are a galapagense with uncertain quantity of galapagense in it available commercially and a variety called coyote.

I think a yellow PH2 PH3 would be nice. I hope Carol gets that funding.

A logical way to proceed with Carol's resistant hybrid tomato project might be to create tomatoes within certain classes, yellow, orange, white, blue skinned. So that the desirable traits are all in resistant populations.

In Carol's absence my plan is just to proceed to the F2 then send them to someone with blight or freeze till blight shows up here.

Another way to go would be recurrent back crossing to a homozygous PH2 PH3. So, stabilize yellow, then cross back to Lizzano and repeat until the probability of resistance is higher.

[William S.]

J and L gardens sells a lot of reportedly cold tolerant stuff.

Interestingly their variety "Wild Child" claims to have some blight and cold tolerance from LA 1777 and it is a dwarf. I got a packet to grow in 2020 to try to see if it's useful to me.

http://jandlgardens.com/xencart/index.php?main_page=product_info&products_id=577

You've listed a lot of my same goals. It's a long road to combine them all in the same tomato. Say you had Lizzano, Wild Child, and Coyote. You could cross Lizzano with Wild Child and Lizzano with Coyote. Then select a yellow offspring in the F2 with coyote. Cross that with the other cross and get a yellow in the F2 of that. That looks a lot like four years of breeding. You could do the F1's as a winter grow out with a nice grow light and warm room. Then its two years. I want to set up a indoor grow area particularly would be useful for growing winter generations of little plants like Lizzano and making crosses with them. Would you have the cold hardiness and disease resistance though after all that work? Maybe in the grex but stabilizing them might be difficult. You could use a fridge to select flats of seedlings for cold hardiness. However you need late blight or access to genetic testing to know if you have PH2 and PH3 stabilized. So it might be more like, cross Lizzano or other PH2 PH3 Homozygous variety with X, produce lots of seed from the F1, and send it to someone who does have late blight or access to genetic testing or freeze it for later in case late blight shows up in your neighborhood soon.

My main crossing method seems to be to exploit / enhance the natural out crossing rates of exserted stigma varieties. I seem to only be able to emasculate successfully inside or in the greenhouse which isn't very much time right now. Most of the growing season my tomatoes are outside. So an variety like Big Hill is useful; Joseph Lofthouse bred it for exserted beefsteak stigmas. Sturdy and easy to work with. So I just dip the exserted stigma in my pollen collection spoon. Big Hill isn't available for 2020 though. I have a sub-plan to cross Big Hill with Lizzano F3 in 2020 using that method, but it isn't my highest priority so will see if I get to it. My thought with that, would be to try to get an exserted stigma cherry with bicolor back. Then take that, and cross it back to a homozygous PH2 PH3 maybe Iron Lady this time as that could lead to an exserted short season bicolor beefsteak with a good chance of being late blight resistant.

Another approach we have talked about on here to getting late blight resistance is that our wild crosses should have some just as "Wild Child" reportedly does. Joseph for his self incompatible tomato project distributed a lot of seed out in late blight prone parts of the country and some of the plants did well and volunteer growers sent seed back to him. That's the project that is going to take up most of my time and space in 2020 and one of the reasons I might not get that little Lizzano x Big Hill cross made right away. Have some exciting 50% Big Hill F2 seed grown for it and need to do a big grow out of it.

[Andrew Barney]

I like this one,  the one William mentioned. Obviously a cross of some sort,  though the company won't admit that. I like it though.

https://store.underwoodgardens.com/Wild-Galapagos-Tomato-Solanum-cheesmaniae/productinfo/V1182/

[Dominic J]

There's no issue with importing "small lots" of tomato seeds into Canada. It's just that Harris and Territorial Seeds don't ship outside of the US. So if you decide to emigrate, as long as you don't have more than 500g of seeds at a time, won't be any hassle. And if you have more, probably won't be much of a hassle either.

Gonna try to cross Lizzano with a bunch of other things, including itself, to then play with in successive generations. I've mostly just grown Mountain Magic so far, never grew all that many tomatoes, so I'll get to try and experiment with a few new other varieties, get to taste them. Key criteria: the kids need to want to eat them. And for that, it needs to be small, because they don't eat anything larger than 2", and ideally it'd be down to about 1". Yellow color increases the odds of them being willing to taste it. Also, I like bright yellow. It's nice.

I figure I'll cross Lizzano to Korol Sibiri, then cross these offspring to each other, then test the F2s for cold tolerance, and keep seeds from the ones with the smallest yellow fruits, and then cross back to Lizzano, and then again to themselves, and then again cold tolerant smallest yellow fruit, and then back to Lizzano, rinse and repeat.

That's the current idea, though, might change in less than an hour. XD

Yellow being recessive, I can work with red F1s with a yellow parent knowing it's heterozygous for it, but if I keep going without re-selecting for yellow, then I no longer have any idea if the red tomatoes I'm using still have the allele or not. And back-crossing continuously to Lizzano seems the simplest means of increasing the chance of my line being homozyhous for Ph2+Ph3.

[Dominic J]

Actually something more along the lines of

A1: Lizzano x Korol Sibiri
A2: Lizzano x Blanche du Québec
A3: Lizzano x Pear Tomato (Yellow)
A4: Mémé de Beauce x Pear Tomato (Yellow)
A5: Estamino x Korol Sibiri
A6: Mountain Magic x Blanche du Québec

B1: A1 x A3
B2: A4 x A5
B3: A2 x A6

C1: B1 x B3
C2: B2 x B3
C3: B2 x Lizzano

D1: C1 x C3
D2: C2 x C3

E1: D1 x D2

F1: E1 x E1

All while selecting for yellow skin, yellow flesh, spherical-fruit, dwarf, indeterminate, cherry-sized, and cold tolerance, where applicable. And waiting for friends with gardens or farms signal LB issues so I can try to assess resistance of my crosses with that innoculum. Not the slightest idea how long that would take to stabilize.

[William S.]

Complicated scheme! Represents six generations and nine parents? Interesting approach.

9 plants A generation
6 plants B generation
Larger numbers in subsequent generations because segregation would start despite F1s in each generation.

[Dominic J]

I like doing things complicated.

This way, the As would largely be heterozygous for traits I want, which means on the B list I can start selecting for those recessive traits. Korol Sibiri, Blanche du Québec, Pear Tomato (Yellow) should all be homozygous for yellow flesh allele (and yellow skin, except maybe Blanche du Québec, which appears to either have clear skin or yellow skin depending on the picture I'm looking at). Lizzano, Pear Tomato (Yellow), and Mountain Magic are all cherry-sized. Lizzano is homozygous for Ph2-Ph3, but Pear Tomato (Yellow) [ok I have some doubts on this one] and Mountain Magic also posses LB resistance. Estamino possesses a whole bunch of resistances, but I otherwise don't have the slightest idea what to expect from it. Mémé de Beauce is all the crazy around here, so, you know, why not. There's also dwarfism in there that comes back a few times over the crosses, and supposed cold resistance (Korol Sibiri and Blanche du Québec came up in a few cold lists).

I figure with 6 generations of crosses like this, I could probably breed out the traits I don't want present in the original varieties (large fruits, red color, determinate fruiting, irregular and pear shapes, clear skin, and whatever the hell Estamino is going to give me). Or at least do a good enough job at it so as to be close to stabilizing it. My main concern will be hoping to hang onto as many resistance genes as possible, without really being able to look at them directly. As such I'll probably have to try to maintain large breeding populations as possible (as much as I can on a garden-size, lol) and accept a fair amount of heterozygosity and instability in those traits. All while also making as much backups of each crosses as possible so that if ever I do get the means to more reliably test for certain invisible traits, and I find out I accidentally bred them out, then I could go back to these to find the most recent cross still having it and not having to regress all the way back to the initial starting varieties.