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General Category => Nightshades => Plant Breeding => Tomatoes => Topic started by: Cathy A on 2022-06-17, 09:05:50 AM

Title: Planning for a 2023 tomato breeding project
Post by: Cathy A on 2022-06-17, 09:05:50 AM

I'm beginning to make plans now for a small-scale tomato breeding project aimed at getting varieties well adapted to zone 4 Vermont. Goals include a long, productive season; ability to reseed, sprout, and make productive fruit without needing to be pre-started inside; some frost tolerance, able to handle ~30F without cover or mid-20s F with cover; and ability to set fruit when nights are below 50F and days are cool but not cold; and tolerance for growing and fruiting in less than full sun.

I've been gardening in this location for almost 10 years, including tomatoes for most of that time. I've tried a number of varieties, including Sub Arctic, Siberian, Celebrity, Sungold F1, Amish Paste, Roma, Brandywine, Black Cherry, Isis Candy, and a few others.  Generally any of these produce good tomatoes in my location, growing in excellent soil (not my native clay, class 6w) in well-drained raised beds. They get good sun for some hours a day, but there is no place in my yard surrounded by forest that truly gets full sun. Last frost is historically around May 23, first frost around September 23, though it's not unusual for last frost to be a week or two either way and first frost often has several weeks of Indian summer afterward with little frost. Winter here lasts about 5 months, typically has 1 - 2 feet of snow on the ground from late December through March, and temperatures are routinely below zero F at night during the coldest months.

I have a healthy pollinator population of wild solitary bees, made up of bumblebees or a similar relative. The garden is mostly organic, with no pesiticides used, no major pest issues except snails and slugs (beer traps and hand-picking deal with them), and an occasional use of 10-10-10 to supplement compost.

I can put about three 4x4 beds, 48 square feet, into tomatoes after allowing space for the rest of my garden.  I grow intensively, so each bed could support anywhere from 9 plants with plenty of space each to as many as 25, more tightly packed.

One year early in my Vermont gardening life, I tossed all the unused, unripe, split, going bad, etc. tomato fruits back in the bed at the end of the season expecting them to compost. Many of them sprouted and produced tomatoes the next year, though later than ideal. So I know it is possible to start tomato seeds directly in outdoor soil at this location.

This year I am growing Amish Paste (started from seed myself), Sungold F1 and Brandywine (both purchased as plants locally).  These are not part of the project, which I have only started thinking about in the past week. In previous years I have struggled to start tomatoes from seed indoors, but after upgrading my weak fluorescent lights to proper grow lights, this year it worked extremely well. I use tomatoes both fresh and for tomato sauce, and planning salsa for the first time this year, so a mix of paste and "eating" tomatoes is best.

Right now I'm trying to figure out the best varieties to use for a breeding project beginning in 2023 so that I can order them this fall. A few obvious candidates are:

 Glacier
 Sub Arctic
 Jagodka
 Siberian
 Kimberely
 Black Cherry
 Matt's Wild Cherry
 Roma
 Sungold F1

for a good range of genetic material.   I don't believe any of these have true frost tolerance, so I think it would be a good idea to include Solanum hirsutum, S. habrochaites, and/or S. huaylasense. I don't want too much beefsteak genes in the mix because those tend to be late, which would defeat the purpose.

I'm unsure to what extend this should be treated as a "promiscuous landrace" (thank you, Joseph Lofthouse, for that great term) and to what extent I should push it in the desired direction with controlled hand crosses. If I do succeed in getting a good landrace going, I may eventually try to isolate some homozygous lines with particularly good traits from it.

I see a number of posters on these forums are doing similar projects in different locations, though most of them seem to be in zones warmer than zone 4. So far my online research has not turned up any cultivated tomato varieties that claim true frost tolerance, even those from places like Russia where it might be expected. I did see some mentions on these forums, complete with photos, of a few plants that did survive a frost while most died. How much of this is from Mendelian genes vs. epigenetic switches vs. microclimate doesn't seem to be well understood.

Suggestions are very welcome!
Title: Re: Planning for a 2023 tomato breeding project
Post by: Vesa Tee on 2022-06-17, 01:36:31 PM
You have an interesting project, I am sure you will get a lot of good suggestions and inspiration from this forum.

You already referred to the Russian varieties, so maybe you have already studied them. One good source of information is Tatiana’s tomatobase, by simply searching there with key words like ”cold tolerant” or ”frost” or ”Saraev” might give you some interesting reading. I have never truly tested these Russian varieties on how cold tolerant they are so I cannot comment them much more than this.

 http://tatianastomatobase.com/w/index.php?title=Special%3ASearch&profile=default&search=Saraev&fulltext=Search (http://tatianastomatobase.com/w/index.php?title=Special%3ASearch&profile=default&search=Saraev&fulltext=Search)
Title: Re: Planning for a 2023 tomato breeding project
Post by: William Schlegel on 2022-06-17, 03:32:07 PM
I grew some of the Saraev tomatoes my first serious tomato breeding year in 2017. My conclusion was that their special abilities were the result of epigenetic activation that had subsequently been deactivated again. That they are in fact pretty ordinary tomatoes which just happened to get some kind of epigenetic effect. Though that suggests that it might be possible to reactivate them. I suspect that when tomato plants survive being exposed to frost that such an activation is one possible outcome. However, I haven't actually observed it yet and now I am in year 6 of tomato breeding!

In 2017 when I started, I had many of the same questions particularly about the wild species. I have to report that particularly in regard to frost and cold tolerance I still don't know for sure. I suspect that many of my favorite short season tomato varieties are cold tolerant and or stress tolerant.

I have relied heavily on the prior work Joseph Lofthouse did including following many of his variety suggestions and working with his varieties and populations. For instance, I have F1 and F2 tomatoes I am growing this year whose pedigree is roughly this: (Unknown Joseph Lofthouse 2017 tomato landrace potato leaf x Blue Gold in the F4) x Big Hill / HX-9 and the pedigree of Big Hill is Jagodka x Hillbilly. So they are tomatoes I have bred from 75% tomatoes obtained from Joseph and 25% from Brad Gates.  I now think of this iteration of the project as the Mission Mountain Morning or MMM for short tomato line. However I already have seeds of the MMM line crossed to Aztek microdwarf and hope to harvest seeds of it crossed to Sweet Cherriette and two currant tomatoes sometime soon!

One important point that arises from that is that you don't have to start from scratch! We all stand on the shoulders of folks like Joseph Lofthouse and Brad Gates amongst many others going back in time a very long time.

I have shared a couple of my tomato projects through Experimental Farm Network and Snake River Seed Company as well as my wife's online Etsy store. I intend to continue with that. I also happily trade seeds with folks here in the USA.

Joseph's promiscuous tomato project which looks to be currently available in the "Wildling" form https://store.experimentalfarmnetwork.org/collections/tomatoes/products/wildling-panamorous-tomato on EFN even right now already contains a substantial amount of genetics from a promising mixture of Solanum habrochaites and Solanum pennellii crosses. In more recent generations the results have been downright edible maybe even palatable or on rare occasions amazing! Likely fresh seed lots will be available for the winter 2022-2023 seed acquisition project. I myself have a fruity flavored isolation garden with two promising promiscuous project strains from my 2021 garden which I have been calling Little Pumpkins and The One. If they taste good again this year I'll have seed to share one way or another.

I don't currently have a whole isolation garden devoted to a cold or frost tolerance breeding project but am interested in that as well, I am unsure how best to proceed with that particular project.

My top ten favorite tomatoes for breeding with after the 2017 tomato season included some things like Sungold F1, Sweet Cherriette, Earl's strain of Jagodka, Krainiy Sever, Blue Ambrosia, and Coyote. 

Now that it is 2022, I am not sure how many of my original favorites are still important. I find new favorites, often from segregating populations, most years.
Title: Re: Planning for a 2023 tomato breeding project
Post by: Steph S on 2022-06-17, 04:57:08 PM
Some excellent points already from Vesa and William.  Standing on the shoulders is what it's all about.  No shoulders, no world of plant breeding. 
I agree with Vesa that the shoulders of the Russian breeders are very worthy of standing upon, when we look for material for cold climates.  Tomatoes are extremely popular throughout Eastern Europe and some very fine OP varieties have come from their stables. I am quite reliant on them myself, for the cold tolerant partner in a cross, as in my trials of over 100 OP's it soon became clear that the Eastern Europeans were far better suited than many of the glorious beefsteaks famous for their flavor in the SE and NE US where the season is quite long compared to ours.
I have accepted the limits of cold tolerance in tomatoes.  Someone else may succeed in pushing that boundary, but it is beyond my capabilities to take it further than has already been done by professional breeders.  I accept that they are frost intolerant, and cultivate and breed those that are tolerant of cold and low light, yet adaptable to extreme temperature changes which we get in the greenhouse when the sun suddenly comes out, while also doing my part to adopt techniques that keep them fruiting, including shelter, temperature moderation etc.  I have seen my most adaptable cold tolerant tomatoes sprout from the stump after frost killed the tops in the fall..  However this is not a meaningful feature for me.  Frost damages the fruit if you fail to harvest before it.   Sprouts from frost killed plants have little chance of producing fruit before it frosts again.  So my focus is strictly on the crop, and not erudite values of "tolerance" which don't produce something to eat.
I have trialed enough OP's to know that many of them will not grow fruit when it's cold, some won't set, and others set but won't grow them until nights hit 60F.  Then there are still a very large group of OP varieties that will set and grow fruit in quite cool conditions.   Setting with nights under 50F is not a problem, but growing fruit when daytime highs don't reach 60 F is pretty much a null group.   
I have had plenty of success crossing between the more cold sensitive tomatoes and those that do better.  Offspring seem to pick up the cold tolerance very well, so I do get food even in early generations of many of these crosses.   There is a huge pool of varieties from Eastern Europe to play with.
In the ones that you mentioned, I have used Black Cherry as a flavor parent in crosses with earlier and more hardy tomatoes.  This worked quite well, the flavor genetics seems pretty dominant and the weaker plants in cold tolerance terms get weeded out without catastrophes like a year of losing half your crop.  There's lots of vigor in Black Cherry but they are sensitive to temperature extremes and prone to produce vegetative growth at the expense of fruiting.  Many yards of vine for a few tomatoes, sometimes.
I've also done some breeding with Kimberley but most of these lines are on hold (pending time and space) because they are chronically susceptible to pests cw other lines.  Kimberley has early flowering genetics which will only produce an earlier crop if the temperatures are right.  So starting them early is a bit wasted.  The trait would be really useful if the plan is to start them later and have them transplanted at 6 weeks of age no later, into temperatures that suit their fruit production.  Kimberley and its crosses can win the bragging rights for first ripe fruit easily enough, for the one that is setting when you transplant them.  The main crop though will not set any earlier than Stupice and similar early varieties, unless conditions are warm enough.  So it was not a key to earlier crops for me.
I don't have a handy list of the varieties trialed and how they worked out but if there's something you want to trial and you run it by us I will remember it if it's one that I grew.  A lot did not get invited back for a second season.   However there are a group of OP's that were good enough for my farming friends to adopt and continue to grow here, meaning that they produced reliable crops in spite of our fickle seasons and became favorites, or at least were worth the occasional grow. 
Cherries are always a great bet if you're growing outdoors.  Any smaller fruit has a much better chance to ripen.
I really liked Isis Candy but they hated my crowded shady greenhouse and only produced when I ditched them outdoors. ;)




Title: Re: Planning for a 2023 tomato breeding project
Post by: Adrian on 2022-06-18, 06:08:02 AM
We don't have the sames climates and maybe not the sames varietys but we have harvested our first tomato the 1st september the last year It was the varietys san marzano lungo, andine cornue and canestrino di lucca and costoluto tasty but too  late.My idea was to found more early tomato. bloody butcher is the most early for me!
Most early than morettino.
San marzano lungo was the most productive the last year.
Someone has offer  F2 of tiny tim x green velvet. I think i can have early and tasty tomato.
I think more and more to try cross with bloody butcher.The first bloody butcher is mature today this year!
Do  you think its a good idea to cross bloody butcher with dwarf tomato  (tiny tim x green velvet f2)for increase earliness.

Have early tomato is even usefull for us in france.
I think for harvested tomatos the most long time it important to have differents earliness.
A small test for have more early tomato was to did the cross san marzano lungo x costoluto but the F1 is weak.
Maybe if i select F2 i can have a correct result.
Title: Re: Planning for a 2023 tomato breeding project
Post by: Cathy A on 2022-06-18, 08:36:08 AM
It's great to hear from so many experienced tomato breeders. This is the kind of feedback that I need. And thank you especially for the reminder that building on existing work could speed things along.

Vesa Tee: "You already referred to the Russian varieties, so maybe you have already studied them. One good source of information is Tatiana’s tomatobase..."

I like Tatiana's Tomatobase (TT), and often look there. It has one gap, though; it often doesn't show current sources for interesting varieties, which I may or may not be able to find elsewhere. For example, I'm interested in trying Rozovyi Myod for reasons have nothing to do with the breeding project discussed in this thread. TT lists seed availability through 2018, but nothing thereafter. I see some mentions of Rozovyi Myod (or more often, its translation as "pink honey") occasionally elsewhere, but am concerned it may not actually be the same variety.

William's comments about epigenetic activations for cold subsequently being deactivated points out a real problem with trying to breed a stable cold-tolerant line. I'm not sure what the solution might be.

After reading William's comments, I like the idea of getting wild genes into the mix through a blend that already incorporates S. habrochaites and S. pennellii, but is already crossed with cultivated tomatoes and palatable.

Steph S, I like the idea of standing on the shoulders of Russian breeders. Could you please give me a list of specific Russian varieties you would recommend as a starting point?  Some Russian varieties were likely bred for conditions down by the Black Sea, which would be completely different from something bred farther north. It's great to hear you say that cold tolerance crosses well into other varieties.

I'm not yet willing to accept the existing limits of cold intolerance in tomatoes, especially when wild relatives grow thousands of feet above sea level in what most be very cold climates. I hold up beans as a comparison. I can get green beans for a longer growing season than I can tomato fruits, even though beans have no frost tolerance either. Beans grow faster, produce edible beans sooner, and continue to produce beans right up through first frost. They will usually survive a frost or two covered and continue making beans even when nights are cool. What would be the equivalent for tomatoes?

Ultimately, my goal is to get fresh tomatoes over a longer growing season. Right now, I am getting maybe 2 months of tomatoes at best. My goal would be to get them for about 4 months, taking into account effects of early starts indoors, perhaps cold frames outdoors in spring, row covers late in the season, and so forth. I'm willing to trade off taste for this, perhaps breeding taste back in at a later time.

That could be done through a mix of early tomatoes (which are able to sprout early, tolerate a late frost without dying even if they are set back somewhat, produce fruit quickly for early use in spite of cool (but not frosty) nights, produce fruit all through the hot summer, continue to set fruit when nights are below 50F and days are warm but not hot, survive early frosts under row covers, and finally end the season.

This does not have to be done through a single variety, and probably can't be. It could be a landrace with a wide range of genetics, or several homozygous varieties producing early, mid, and late tomatoes.

For breeding stock, I'm now thinking something like:

   Cold tolerance: Sub Arctic, Siberian, Lofthouse Wildling, (other Russian varieties?)
   Wide genetic range: Sungold F1
   Taste:  Black Cherry
   Disease resistance: Suggestions?  Is it needed since I have not had significant disease issues?
   Early:  Bloody Butcher, Stupice

I'll continue to think on this.
Title: Re: Planning for a 2023 tomato breeding project
Post by: William Schlegel on 2022-06-18, 09:21:05 AM
Stupice is an old standby here for earliness but it and Bloody Butcher didn't make it that high on my earliness list. I would reccomend for earliness: sweet cherriette, 42 days, forest fire, anmore dewdrop, coyote, Jagodka earl's strain, terrior seeds galapagos cherry, silvery fir tree, and the tomato Joseph calls Brad and it's descendents. I suspect that earliness will be different for each of us in far apart climates. Therefore I reccomend trying a lot of early varieties to find out which does the best for you. I suspect you will find existing earlier tomatoes I sure did. Some of my own lines have occasionally performed very well in this regard under specific conditions such as amongst direct seeded plants. I also finally have a cross maturing with sweet cherriette.

I definitely love exploring the Russian varieties. One of my favorites is Krainiy Sever. I successfully direct seeded it in 2017, it was early, and it keeps the fruit off the ground because it is a determinate dwarf.

Don't be too disheartened about epigenetics. If you happen to activate something it should stay on a few generations and keep staying active if the plants keep encountering the trigger. I.E. it goes away when grown in say mild climates. 

I breed with Sungold F1 and descendants they are good for earliness and flavor. Blue Ambrosia a sungold and antho descendant was a early mainstay of my projects that led to a tomato I called exserted tiger and shared with the world through Snake River seeds so other people could use it. It is basically a vehicle for stripes, exsertion, anthocyanin skin, and somewhat short season.

For cold tolerance I am uncertain I have a few I've been investigating but it just seems like most tomatoes do OK for me as long as they are around 75 days to maturity or sooner. I have a specific accession of Solanum habrochaites I obtained for this but it was killed by a severe frost last year. Our nights can be cold here but not cold enough that I don't get seeds back on varieties that don't have this or at least aren't known for it.

I would also reccomend coyote, amethyst cream, and terrior seeds galapagos island tomato for flavor. I am in the first generation of trying to isolate good flavor from the promiscuous project. I am trying some new tomatoes this year for flavor specifically. Including I am growing Black Cherry for the first time.

Disease resistance is out there, I am dabbling with it but frost is my disease so far. I am intrigued by Galahad F1, Purple Zebra F1, and have obtained a couple wild accessions to target specific disease problems. If we who dont have it get hit by a disease I think it's important to note that you'll be able to cross your favorite projects with disease resistant lines inside over the winter. Also it is possible to grow an F1 and get to a variable F2 inside over the winter. Might be good to obtain some disease resistant seeds just in case but not a necessity if frost and cold are your primary opponents as they are for me.


Title: Re: Planning for a 2023 tomato breeding project
Post by: Adrian on 2022-06-18, 02:29:37 PM
 Do you think a dwarf tomato is a good idea for improve the earliness?
Title: Re: Planning for a 2023 tomato breeding project
Post by: William Schlegel on 2022-06-18, 03:09:01 PM
Do you think a dwarf tomato is a good idea for improve the earliness?

With Krainy Sever I saw evidence that both dwarf and early is possible but I don't think dwarf itself is going to improve earliness. An early dwarf might. I see the advantage more in the sturdy stem since I don't provide support. So not incompatible but two different things.
Title: Re: Planning for a 2023 tomato breeding project
Post by: William Schlegel on 2022-06-18, 03:13:40 PM
We don't have the sames climates and maybe not the sames varietys but we have harvested our first tomato the 1st september the last year It was the varietys san marzano lungo, andine cornue and canestrino di lucca and costoluto tasty but too  late.My idea was to found more early tomato. bloody butcher is the most early for me!
Most early than morettino.
San marzano lungo was the most productive the last year.
Someone has offer  F2 of tiny tim x green velvet. I think i can have early and tasty tomato.
I think more and more to try cross with bloody butcher.The first bloody butcher is mature today this year!
Do  you think its a good idea to cross bloody butcher with dwarf tomato  (tiny tim x green velvet f2)for increase earliness.

Have early tomato is even usefull for us in france.
I think for harvested tomatos the most long time it important to have differents earliness.
A small test for have more early tomato was to did the cross san marzano lungo x costoluto but the F1 is weak.
Maybe if i select F2 i can have a correct result.

I think taking things to the F2 and maybe even to the F3 is a good practice sometimes the early generations dissapoint but that doesn't mean we should discard a project. The genetics need time to segregate.
Title: Re: Planning for a 2023 tomato breeding project
Post by: Steph S on 2022-06-18, 06:11:48 PM
With regards the Russian/Eastern European varieties, I would advise you to trial as many as you can, to decide which ones you like as parents for your environment.   In choosing plants to trial I always had to limit my choices to 80 days or less aka "midseason" varieties at latest, but these latest ones were always crossed with earlier parents for a better fit for our season.
It isn't always easy to decide which plant will make a good parent.  Some crosses I made from tasty parents ended up shelved after a couple of generations, because the fruit wasn't tasty.  So the advice I would give you is to make lots of crosses, and see which lines are really pleasing to you.
There's a huge variety of tomatoes in that geographic region, and you can find quite early and cold tolerant lines of all shapes and sizes and colors.  So it depends on your goals, what size and shape you intend to aim for.

As for sourcing seeds, I would say you should drop in and join at Tomato Junction sometime before the fall, and join in on the MMMM swap.  There's usually an Eastern European category there, and you'll end up with lots to trial.  If you're looking for specific varieties, folks will help with that too.  Our friend Shawn is also in Vermont, and he's been curating and distributing the seeds from Carolyn Male's collection for several years now.  There were lots of Eastern European varieties included, and since they had all been pre-screened by Carolyn you pretty well could be assured there was something special about each one.  And Shawn can tell you how they grew for him in VT.  So you can get a great start on tomato material to trial in that seed-sharing community.  Many many more varieties than I personally have grown.

Title: Re: Planning for a 2023 tomato breeding project
Post by: William Schlegel on 2022-06-18, 08:50:46 PM
That trade deal at Tomato Junction sounds fun but I overdid it a little last winter with tomato trades and acquisition, and I don't think I've done them justice. I think I would not be able to manage hanging out on another forum! I grew the ones I got last winter but some ended up crowded. I don't know how folks with really big tomato collections do it.

One key component of breeding is trying and or trialing what is already out there, and it is always possible that the perfect tomato for your needs already exists what with thousands of varieties available in the world. I think I have tried maybe a couple hundred.

I want to try more but I also really enjoy the variation that has arisen in my own garden as well as the variable populations other plant breeders have shared with me. Like Joseph's promiscuous project has been quite the experience growing this year and the prior four or five in its various iterations.
Title: Re: Planning for a 2023 tomato breeding project
Post by: Joseph Lofthouse on 2022-06-19, 12:01:23 AM
Tomatoes are a tough species to use for breeding in frost/cold tolerance. Because they are from low elevation in the tropics, near the ocean. There just isn't any need for the species to have frost tolerance. Then to make matters worse, 95% of the available genetics were left behind during domestication and heirloom preservation inbreeding, which means that there is trivial genetic diversity from which to select. It's really tough to make any sort of meaningful advancement breeding only with domestic tomatoes.

A decade ago, I did a careful frost/cold tolerance trial with varieties that were highly recommended. They were mostly a disaster. None of them were frost tolerant. Jagodka, a Russian variety,   set fruit at low temperatures, and matured them in the cold. The region where it was developed is a low elevation, maritime climate: Coolish weather both night and day. Few Growing-Degree-Days are available.

Even the wild species from high elevation (such as solanum habrochaites at 11,000 feet), rarely experience much cold. Sure, the ancestors of the Beautifully Promiscuous and Tasty Tomatoes project survived frost, snow, and cold weather for a couple months after the domestic tomatoes died. I haven't restarted the cold/frost tolerance trials after making the crosses. Wildling, Q-series, Big Hill, and anything from the panamorous of polyamorous lines are descended from Solanum habrochaites, and Jagodka. Silvery Fir Tree was another ancestor.

I may restart the frost tolerance project, after I get a population of tomatoes that can be direct seeded.  I'm generating high enough volume of seeds, that I could throw 10.000 seeds at a frost tolerance project.
Title: Re: Planning for a 2023 tomato breeding project
Post by: Steph S on 2022-06-19, 04:13:59 AM
I absolutely agree that you should work with the wild relatives crosses to pursue frost tolerance.   

There's a general principle that is useful, when you want to produce a trait beyond the scope of the current parent pool, and that is to make as wide a cross as possible, meaning the parents are as far from closely related as possible.   When you work with wild relatives or their descendants, you are really maximizing that.

My own limits in breeding are just that, limits due to an extreme climate and having to grow in limited greenhouse space, with the additional limit that I have to produce a food crop at the same time.  So that is why I haven't pursued the kind of tomato projects which are possible with ample outdoor growing space.   I've tried to make my crosses as wide as I can by choosing parents from different continents, and also stirring the pot by making crosses between unstable generations.  And I've added stressful conditions to the breeding sometimes, by making crosses late in the season when conditions are already suboptimal.  IDK if that helped, my plants are always subjected to stress from the get go in any case. ;)
Title: Re: Planning for a 2023 tomato breeding project
Post by: Cathy A on 2022-06-20, 08:14:56 AM

From my reading, I've come to the same conclusion as Joseph Lofthouse. Getting true frost tolerance in tomatoes is going to require getting wild genes in the mix, and even then it's a low probability that may require the widest possible set of wild ancestors. Throwing 10,000 seeds from the most diverse possible lines at frost seems like the right approach, but it's beyond my own capabilities due to limited space. It may require new mutations to occur, which again means large plots with as many plants as possible.

However, my key objectives could probably be achieved by breeding a line or lines that develop fruit early, grow quickly in cool weather, continue to set fruit in cool weather as fall approaches, and can survive significant frost under a heavy row rover or temporary hoop house, even if they don't have actual frost tolerance. I've found that just about any tomatoes will survive a light frost here under a heavy row cover.

I don't see many serious amateur tomato growers growing them outside in zone 4 or colder, at least not in North America. Many grow them in a greenhouse, or in warmer climates zones 5 and south. So I don't think much work has been done on creating the most productive lines for cool weather here. Russian and nothern Europe may be different.

The varieties I've seen suggested on other sites or forums for these conditions tend to still require significant heat, and have been bred for a short warm/hot season rather than actually thriving in cooler conditions. (By contrast, I know one gardener in Canada who can't grow tomatoes outside because it isn't warm enough most nights in the early part of the summer to set fruit (below 50F), with very few nights staying above 50F, then she sees her overnight temps drop very quickly in late summer so still can't set fruit. Short-season varieties don't help her if they still require that nights stay above 50F.)

So I'm looking for cool climate tomatoes that aren't just faster from transplanting to producing fruit, but will grow and thrive in cool weather, and continue to set fruit when days are warm and nights are cool. None of this requires actual frost tolerance, though it would be nice to have.

I plan to do a mix of hand-pollinated hybrids across many of the starting varieties along with allowing some to self-pollinate.

My updated list for first-year genetic material is:

  Sweet Cherriette
  Forest Fire
  Big Hill (Jagodka cross from Lofthouse)
  Coyote
  Black Cherry
  SubArctic Plenty
  Siberian
  Sungold F1
  Lofthouse Wildling
  Glacier
  Kimberely (optional)

I can't test and cross too many varieties at once in my limited space, so new material may be added in year 2 in addition to hybrids from the year 1 material. Does this list seem like a reasonable starting point? Ten varieties with 2 plants each is a reaonable number of plants, though it won't be practical to do every possible cross (90 options even without Kimberely!)
Title: Re: Planning for a 2023 tomato breeding project
Post by: William Schlegel on 2022-06-20, 08:52:19 AM
https://jandlgardens.com/xencart/index.php?main_page=index&cPath=81&sort=20a&page=1&zenid=93tpdsua38l2boas5k9f5amlr6

A favorite plant breeder whose work I have been sampling for years now in New Mexico has an interesting list of cold tolerant varieties. Lee Goodwin. Ambrosia Gold is his Sungold dehybridizaton. Krainy Sever also makes the list.

Glacier is an old standby here but I don't grow it anymore because I think I've found even earlier tomatoes. Subarctic plenty deserves a better grow out from me but I don't think I have space to do better grow outs same for Siberian neither rose to the top of the list but may have if more plants had been grown. Or if I equalized things by using fresh seed.

Fruit set: nights above fifty have been sparse this year. Sweet Cherriette, Mexico Midget, and Black Strawberry (Lee Goodwin's work) have fruit set already in the open field. Might be more out there.

Standouts from my 2017 attempt:

earliest:
Sweet Cherriette
Jagodka (this was the strain I got from Earl)
sungold F2
Anmore Dewdrop

Almost as early:
Tumbler F1 (note this is Anmore Dewdrop's parent)
Krainiy Sever
42 Days
Coyote
forest fire

Takeaway for me in retrospect: Sungold F1 and Krainiy Sever could be a really interesting cross for flavor, earliness, cold tolerance, and dwarf growing habit that keeps the fruit off the ground.

In subsequent years I have found a few more interestingly early varieties including Joseph Lofthouse's Brad and Terrior Seeds Galapagos tomato.

Title: Re: Planning for a 2023 tomato breeding project
Post by: Steph S on 2022-06-20, 04:01:08 PM
Couple of thoughts about your lineup and plans.
Why two spaces for each variety?  If I only have 20 spaces, I would use the space to cast a wider net.  You might make exceptions for variable populations because, obviously, each individual will be unique.  But for OP's, you really don't need more than one, and could have the opportunity to sample more widely those best parents for your site.

Siberian, Subarctic Plenty, Glacier.   What's in a name.  I wouldn't give two spots to any of these, for sure.  I haven't grown Siberian and Subarctic Plenty.  Mainly because they weren't rated highly for flavor and fruit quality, at least in my reading before I made my choices.  Glacier I have grown once, it wasn't determinate as expected so maybe not true to type.  It wasn't a great fruit and I wouldn't use it in breeding.  You are better off using early parents that have promising fruit quality.  Granted that tomato performance can be very site (or season) specific, if you've grown these before and found them good, disregard my comment.  But if you haven't grown them, don't bank on them being the best parent for high quality fruit.   The year I trialed multiple "extra early" tomatoes very few were both early and fit to eat.  Alaska and Kimberley were the best tasting of the lot.   I would definitely use Alaska for both taste and earliness, and probably would've but by mishap ended up without saved seed. Likewise you are better off with the earlies that you listed, which William regularly grows and recommended.

Secondly, I would think about your crossing plan.  You don't want to cross anything closely related, you want to make wide crosses, so think about the origins of the plants in your first year stable.  Your Lofthouse plants are the ones with wild relative genetics, so they are key parents for the frost tolerance.   Sungold is also suspected to have wild relative ancestry, add that to the same side of the parent page. Coyote too.   Think about the fruit quality traits you want to combine with earliness and cold tolerance.  You have Black Cherry (USA, recent, Vince Sapp, parentage not released) as a flavor parent.   You need some more flavor and fruit quality parents in this mix.  OP's from another continent at least, increases the chances of genetic distance.  Besides Eastern Europe, I wouldn't omit Italian varieties either, especially if growing some for sauce, which although genetically narrow have been intensively selected for field production.  Costuloto Genovese rated highly in a study of cold tolerance.  I've grown it and indeed it was very tolerant of conditions here that year.

I originally followed your comments about small fruit and cherries being earlier and most feasible but when I re-read I saw your comments about growing Brandywine - a tomato that is notoriously stingy with fruit and difficult to grow successfully except in its preferred micro environment.  I don't know much at all about Eastern European cherries and small fruits as I mostly grew hearts and beefs looking for size and flavor combined with earliness and climate tolerance.   But I could easily send you a dozen Eastern European/Russian beefs or hearts that did well for me and might be a size or flavor parent for your early cold tolerant match, if you want them.  My seeds are not as fresh as you'd get in a current year swap but they're still good to my knowledge.  Let me know if that would help.
Title: Re: Planning for a 2023 tomato breeding project
Post by: William Schlegel on 2022-06-20, 06:57:44 PM
Just a word about space. I was sort of growing along with Joseph year after year. I realized that I wasn't producing anything exciting. Every year Joseph would send me the exciting new generation and I would grow it. Thing is his gardens were quite a lot larger than mine and he had more of them for isolation. So a couple years ago, during the pandemic maybe, I created a system of six isolation gardens out on the land. So this year actually I have ten isolation experiments some of them only semi isolated. I also stopped growing so many other things and concentrated more on just tomatoes. I think that helps a bit with keeping up with Joseph! Maybe I'll have exciting seed to send his way soon. In fact I suspect I will because "The One" "Little Pumpkins" "Exserted Salmon" are all isolates from last year's grow out of his project and they have lots of offspring this year and if any are exciting two years in a row I think they'll be heading back his way.

You can definitely breed in any size garden, where things get really tricky is the F2 grow outs when you might like a particularly large grow out size. So I guess my mantra is "crowd it, crowd it, crowd it" for breeding. For instance if I could just expand my garden by one four foot by 25 foot raised bed for tomato breeding I might grow 200 severely crowded tomato plants in it one for every six square inches of surface space. I would not expect nearly as much food production from that bed as a similar sized tomato bed I planted for tomato plants to actually do well, but it would allow me to grow variable
material in a relatively small garden.

So do put 25 plants in the same hole, do put 20 plants in the same five gallon bucket, and do crowd it, crowd it, crowd it!

My gardens are sort of shockingly large and spread over about eight acres plus a few in other places. They definitely aren't for good tomato production from individual plants. I have shallow soil too and don't support so individual plants can be quite small. I could probably grow a huge plant like some gardeners do if I dug out the clay accumulation layer, imported or concentrated topsoil and compost and added support. Though somehow that project isn't rising to the top of the list!
Title: Re: Planning for a 2023 tomato breeding project
Post by: Steph S on 2022-06-21, 12:11:00 PM
Crowding definitely works for some traits, but it has its limits.  If you're selecting for frost tolerance or disease resistance in small seedlings or young plants, why not.
Even for taste, in a cherry, you can cram 4 or a half dozen into the space for one plant, and usually get a sample from all of them.
In my environment, I was able to get plants to produce determinate vs indeterminate pattern in about a ? half gallon pot I think.  Or a 1 gallon.  But I was unable to do this in for example the beer cup volume of soil, where they just wouldn't even try to make more than one cluster of buds, for the most part.
Larger fruited tomatoes won't produce at all if they don't have the resources.
At some level of crowding, you will get plants that just go vegetative and don't set or grow any fruit, at least in my environment that's what I've seen.  Shade is an issue for production and also for fruit quality in some conditions - you can end up with uneven ripening (K defects).
Maybe it's a valid goal to eliminate those that aren't the most competitive plants, and if so, more crowding will provide the selection event.  For me personally, there's nothing more disappointing than a plant that doesn't produce any fruit to taste.  Growing a load of vine instead of a load of fruit is contrary my objectives.  ::) (Actually I have one now that I'm anxiously watching - the only PL in my F2 and the only one of them that isn't growing a bunch of fruit by now.  :(  Too crowded in sharing a 15gal tub with a sibling. Already voted least likely to move ahead, and I don't even know what fruit colors or tastes will be. )
If the primary goal is to assess fruit qualities like shape, color, taste, and you crowd to the max, you may be losing out on a chunk of candidates, where they may not produce due to the crowding itself or lucked out on resources due to some other confounding factor.
And of course you can't assess production values without using a full space per plant.
Last year I tried using 2-3 gallon pots to assess traits other than production, and so far it's a reasonable compromise, where I get enough fruit from each to get a proper taste assessment.  I really didn't assess for amount produced, so this year I have half of the plants in 5 gallon pots to check for that.
So I would advise to experiment with different levels of crowding and see what the results are and what actually works for you.  I have heard of large fruited types being grown in small pots where they are fed liquid ferts every week or quite often.  So there are various ways that might suit, depending on your growing space and environmental conditions.   

I have heard another breeder who said he grew 200 F2's and tasted them all in order to select one special tasting fruit.
Maybe it's true?
But in my experience, there's a limit to how many similar tasting fruit you can process and still discriminate between them.  It's not just me, I saw the same thing with my taste panel.  At about tomato #4, they start to say they taste "the same".
Realistically, if you have a half dozen plants to taste you can do that in two sessions, and then compare the best ones in a third.
And then you repeat your test to make sure you didn't miss anything due to degrees of ripeness, the fruit being slightly more shaded, or some other confounder of individual fruit vs overall performance.
I don't think there's any way I could taste evaluate 100 let alone 200 F2 siblings in one season.
For me, if I grow ten or a dozen F2's and don't find anything I especially like, I will shelve it and move on to another cross.
Some parent combinations don't produce what you hoped or expected.  Would you find that special plant by growing a hundred?  Maybe.  Or maybe not.
This is why I prefer to make lots of crosses.  Anything new that I'm growing that's at all promising, I'll make some crosses.  I'm not shackled to any one project, I can cast my net in a way that produces interesting food (and some sauce) and works for me and my space and evaluation limits.  If we have a crappy weather year and there's a line that disappoints, it's the other lines that go forward next season.
If the flavor genetics in a cross is at all promising, you should find something of interest in a dozen F2 plants.  Good taste can even be dominant, and most of your F2's tasty and staying that way through the generations, with a few worthless outliers to 'sauce' in a tasty line. 
If the parents taste genes are really divergent you may get all very different tastes, and in that case, may be worth growing more F2s to sample the full range.  But I would still split it between multiple years for my own space and pace.  And if the tastes are really all over the place, they are probably not going to be stable at F2 either.  So select what you like best, and see what happens in a bigger batch of F3 or later generations.
 
Back-crossing is another way to reduce the space requirement to stack up all the traits you want in one plant. 
Title: Re: Planning for a 2023 tomato breeding project
Post by: William Schlegel on 2022-06-21, 06:56:14 PM
Hmm, those are really good points.

I usually get a few fruits per plants at least in my crowded plantings and I don't worry too much.

With direct seeded crowding I have been disappointed in recent years. Last year I was sad I did not thin the direct seeded promiscuous project seedlings when they had first flowers and eliminate those without exsertion and or open flowers because I just couldn't evaluate the resulting mess later because it was just so dense and fruity. Since that population has volunteered back I might just have to do that thinning step this year. Though so far exsertion is just a lot less this year period.

I have some really important flavor selections to chase this year for maybe the first time and I don't know for sure how I should proceed. I would like to do a tasting event, but I have heard a tasting panel maxes out at about fifty is it? Also, it would be kind of boring to do a tasting of fifty from the same line. I usually taste when I seed save too but sometimes it is just overwhelming. I might have missed something really tasty with super closed flowers last year because I wasn't looking for that.

I am much more likely to find a favorite plant if it isn't so crowded. Last year also when I found favorite plants in direct seeded plantings sometimes I thinned around them to give them more space. Like the red potato leaf exserted in the north east most garden. So many hybrids from that plant! I think I have more seed saved too- don't think I used it all.
Title: Re: Planning for a 2023 tomato breeding project
Post by: Cathy A on 2022-06-23, 07:26:10 AM

After reading the feedback here, and buying and reading Joseph Lofthouse's book _Landrace Gardening_, I'm going to take a different approach to the cool-weather tomato project.

The core of the project will be Panamorous Lofthouse Wildling from the Experimental Farm Network. That will give me a diverse set of genetics that can be crossed readily with my bumblebee population, without needing to do all the crosses by hand. However, since it is not self-incompatible, I will be able to extract promising sublines from it and breed them to be homozygous over several generations. A panamorous line and one or more separate homozygous future lines offers the best of both worlds.

I'll supplement the Panamorous Wildling line with existing varieties, probably including Sub Arctic Plenty, Siberian, Sweet Cherriette, Glacier, Sungold, Exserted Orange, Brad, and Jagodka.

Some of these (Brad, Jagodka) probably overlap with genetics in the wildling line, but I'd like to see how they perform on their own as well. I will hand cross the Sub Arctic Plenty, Siberian, Sweet Cherriette, Glacier, and Sungold back to the Wildling (and/or Exserted Orange?) by taking pollen from each and fertilizing the extended styles of the Wildling plants. Hopefully I will only have to do this for one generation to get some of their genetic line into the panamorous line and let it continue on its own from there.
Title: Re: Planning for a 2023 tomato breeding project
Post by: Steph S on 2022-06-23, 01:15:45 PM
Best of luck CathyA, and I hope you'll keep us posted. :)

William, do they really taste 50 tomatoes at a selection panel?  Or is that the usual OP/heirloom type event, where fruits are completely different but are still rated by all the tasters so you end up with a "top ten" for the year based on everybody's votes?
I've never been to one, so maybe I'm missing something as to how that is doable.
Just 50 bite sized pieces of tomato must add up to quite a bit...  and wondering at what point I would say, no more. :P  I suppose they must stop and eat bread or something in between..  or bread and mayo?  ;D

When I tried taste testing 6 different siblings at one time, we didn't get consensus among 3 of us, so it was less helpful to me.  Three different answers!
Testing 3-4 selections per line, we have done as many as 3 lines in one sitting with bread and fake beer in between, and got agreement among 3 or 4 people.  I have often done tastings like this with different tasters on different days, and still got the same answers, which is great.
But the tasters seem to wear out a long way before 50.
I guess I should ask someone how they do manage with the big heirloom tomato tastings.
Title: Re: Planning for a 2023 tomato breeding project
Post by: William Schlegel on 2022-06-23, 10:25:43 PM
I am dimly remembering the proper number. Have not tried it yet. Would like to.