Year 1 of a Tomato Landrace

Hi everyone,

I have purchased  a great variety of tomato seeds from all over the world and I also have saved seeds from 5 local varieties that I love. The plan is to start a tomato landrace. Our USDA zone is 9b. Anual rain now is 600mm. The region is mountainous. The garden is at 450 meters above sea level.

My question: Is it a good idea to limit cross pollination in the first year to first get to know the varieties from the other regions ?  


Thank you very much in advance!

Kurt

#Lofthouse; #Landrace

I sense that you're fishing for a reply from Joseph, so it'll be interesting to see what he says. I'd personally try to get everything as mixed up as possible as soon as possible. You'll see what your parent lines grow like in this first year, so if the weather conditions are even vaguely normal (if such a thing exists anymore), you'll get the benchmark you're looking for, and then next year, whatever crossing you make happen, will give you seeds, the performance of which you can judge against the parents.

Welcome to Permies!

My mind echos what Christopher has already said but I am FAR from knowing what I am exactly doing right and wrong in my own landrace journey so I'll see what others have to say as well.

Great question.

Hi (neighbor) Kurt!

I am curious about what experts have to say about it!

My short answer would be YES, I think it would be a good idea to at least not promote cross-pollination the first year. After reading Lofthouse book, Going to Seed course, and thinking about it, I think that a good way to develop a landrace departing from several varieties would be:

- Year 1. IDENTIFY WHICH VARIETIES PERFORM (AT LEAST REASONABLY) WELL IN YOUR GARDEN: Sow several varieties without promoting cross-pollination; for instance, instead of interplanting varieties, placing individuals from the same variety “away” from other varieties (and close within variety) to easily perceive inter-variety differences on how they thrive in your garden. Cull an entire variety as soon as you see it struggling in your garden (growing too slowly, suffering diseases...) (similar to the “sibling group planting” but for varieties). The aim would be to not allow pollen from varieties that do not thrive in your garden to pollinate the varieties that you will want to keep. (As Lofthouse says in p. 33 “It’s easier if I don’t introduce traits that have to be culled later.”. This is said in the context of not mixing sweet and hot peppers, but I think it may also apply here). Finally, keep seeds from survivors and especially from those varieties that best perform in terms of production.

- Year 2. CROSS VARIETIES THAT PERFORM WELL IN YOUR GARDEN: Interplant varieties of seeds from Year 1 to maximize cross-pollination (maybe allowing a second chance to some unsuccessful varieties from Year 1 or new varieties), even doing some “freelance hybrids” to enhance cross-pollination in difficult species. Try to identify hybrids and store the seeds separately to give them priority in Year 3. Again, keep seeds from best-performing individuals (this time the identity of varieties may have started to be less important; keep seeds mixed).

- Year 3, 4, 5.... KEEP DEVELOPING, AND THEN MAINTAINING YOUR LANDRACE: Keep sowing seeds from the previous year (and some few older seeds, and new seeds, hopefully also seeds from similar landraces from neighbors ), giving priority to identified hybrids. Start (liberally) selecting the traits you are searching for. Maybe be a bit cautious when introducing new varieties (maybe placing them a bit apart the first year to see how they perform) before allowing them to blend into the landrace.

Personally, with a crop that mostly self-pollinates, such as domesticated tomatoes, I wouldn't do anything to prevent cross-pollination.  I'd assume that most of the seeds I get will be self-pollinated already, and trust that to give me at least a few individuals the next generation that are just like their one and only parent.  Meanwhile, I would cherish any crosses I found that second year, and observe them with particular interest to see what new things they have to offer me.

I personally love variety and exciting surprises, so I think the approach of "just let the plants cross however they want and see what happens" to be fun and relaxing.

I think it's good to get started on diversity straight away! You never know what recessive trait those struggling plants might hold. I've been meaning to read the resilience book that Joseph recommends, which explains how and why to keep hold of those plants that do struggle...however my understanding is that genetics has both spectrum and digital characteristics. With no guarantee that your weather will be the same next year, or that that struggling plant may have a resistance to a particular rare disease, I would keep all and grow out as many as possible for a few years.
Mind you if I had any tomatoes fruit outside here and ripen, I could make a fortune! :P

Roger- great first post! Welcome to Permies.

I'll pretty much echo what Nancy said. It's all evolution, and a "bad" trait in a given set of circumstances can be valuable if (when) those circumstances change. Plus, like Nancy mentioned, recessive traits might not be expressed at all in the parent varieties (especially if some of them are F1 hybrids). I'd say go for maximum diversity! Once you've built up a wide genetic base of plants that reliably flower and fruit in your conditions, you can start narrowing it down to the traits you like (in terms of fruit flavour etc.) And any plants that don't like your particular conditions won't likely flower very much anyways, so even assuming spontaneous cross-pollination does take place (doubtful with most tomatoes) they aren't likely to contribute very much to the next generation.

I'm trying a similar project in a very different climate. Technically started last year, but a poorly chosen planting site meant that none of the plants had time to set any fruit. Maybe it's a wild-goose chase to try growing tomatoes outside on the Norwegian coast, but I'll try nonetheless. My plan is to plant as many different varieties as possible, including some wild species that don't have any issues crossing with domestic tomatoes (pimpinellifolium, cheesmaniae and galapagense), emasculate a couple of flowers on each plant, and pollinate with mixed pollen from all the plants. I might repeat this for a couple of years. The rest is mainly taken care of by evolution. Any plants that are not well-adapted to the site and climate won't have time to ripen their fruits (I fully expect this to be the case for the vast majority of them the first couple of years) and so will be strongly selected against, but still contribute pollen and have the chance to pass on any adaptive traits that might be lurking in there. If I ever get to the point where there's a population that reliably sets fruit, which is far from certain, then I'll start selecting for other traits. Well, we shall see.

Eino Kenttä wrote: Maybe it's a wild-goose chase to try growing tomatoes outside on the Norwegian coast, but I'll try nonetheless. My plan is to plant as many different varieties as possible, including some wild species that don't have any issues crossing with domestic tomatoes (pimpinellifolium, cheesmaniae and galapagense), emasculate a couple of flowers on each plant, and pollinate with mixed pollen from all the plants. I might repeat this for a couple of years.

Yay! You're a braver person than I, Eino! It's a million to one chance but it might just work! I hope you are successful and will be amongst the first to beg for seed off you! Have you a project thread, or is it too early yet?

I think people often overcontrol things. Why don't you just let the strongest win? The natural way.

I highly recommend against trying to make landrace tomatoes from purely domestic varieties.
https://permies.com/t/189854/Tomato-landrace#1564117

People ask me about creating tomato landraces often enough that I want to make a public post…

I believe that domestic tomatoes lack genetic diversity, making them one of the most inbred crops that we grow, and therefore among the most difficult to grow landrace style.

Landrace gardening requires two things:
1- Genetic diversity
2- Promiscuous pollination.

With both of those traits in place, then the crop can undergo survival of the fittest selection for current local conditions.

Domestic tomatoes lack both characteristics. They defied my attempts to turn them into a locally-adapted landrace. I currently believe that purely domestic tomatoes cannot become a landrace.

That motivated me to seek out the traits in wild tomatoes that make them 100% cross-pollinating, which dragged with it a bunch of genetic diversity.

To create a landrace (for example plum) tomato, I would pollinate a few favorite (plum) tomatoes, with a line of self-incompatible tomatoes, and then re-select for the self-incompatible trait, promiscuous flowers, and desired shape/size/color of fruit. The self-incompatible plants donate pollen to the domestic tomatoes. The cross doesn’t work in the other direction. Pooling the pollen from many different pollen donors, (preferably in the neighborhood of 16 to 32) from a self-incompatible population maintained with many parents. And keeping in mind the whole time that promiscuous tomatoes have a many to many breeding system, and best results come from larger populations.

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A good first step with purely domestic tomatoes would be to cull any with closed flowers, and to stop trying to keep them pure, even to, gasp, encourage cross-pollination.

Making manual cross pollinations between varieties with open flowers seems like a best practice. No point introducing closed flowers into the population if you just have to cull them out later on.

Big Hill, descends from a classic beefsteak with open anther cones. Some of the cherry tomatoes have exerted stigmas. Growing those sorts of beefsteaks and cherries close together would help the domestic tomatoes.

Tomatoes exist on a spectrum from fully inbreeding to fully out-crossing. Moving the population somewhat away from fully inbreeding would help them. Introducing some wild genetics would help, especially if the population as a whole retained the beefsteak/cherry type flowers ability for occasional out-crossing, even if mostly self-pollinating.

More and more, I embrace the mixed breeding system.

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Domestic tomatoes as a species approximate the genetic diversity of a clone. 95% of their genetic diversity was lost during domestication and from the heirloom inbreeding purity mania.

One study found more genetic diversity in a single sample of one wild tomato than in all the domestic tomatoes in the study combined.

In the case of tomatoes, I would say that domestic tomatoes are too inbred to meet my genetic diversity criteria for becoming a landrace.

With tomatoes, in my garden, the ecosystem does 95% of the selection, without me needing to cull anything.

I value diseased plants that produce fruit in spite of diseases.

I advocate for the maximum possible cross-pollination in every generation.

I highly recommend discarding the names and stories of all newly acquired varieties, so that we don't inadvertently attribute higher ratings to a variety because we like it's story.

Thank you all for the feedback.

On the subject of including wild species: I have selected the following types, mainly because these were the only ones I could get delivered.

- (Galapagos wild tomato) - S. Cheesmanieae
- (Waimea Wild Cherry tomato) - S. Lycopersicum
- ( Humboldtii Wild tomato) - S. Lycopersicum
- (Rote Murmel) - S. Pimpinellifolium


Are the Humboldtii and Waimea tomatoes "wild" as these two are S. Lycopersicum ?
What ratio between wild and domesticated would be ideal?


Thank you

K

Nancy Reading wrote:
Yay! You're a braver person than I, Eino! It's a million to one chance but it might just work! I hope you are successful and will be amongst the first to beg for seed off you! Have you a project thread, or is it too early yet?

Well, brave or stupid, I'm not sure which... If it works you'll be welcome to some seed. A bit early for a project thread yet, there wouldn't be much to put in it other than a description of last year's failure. Watch for one this autumn. In the interest of science I might make a thread about it even if it turns out to be utterly impossible (a negative result is still a result, and all that) but I do hope there will be some small progress to report by then...

Kurt Viaene wrote:Are the Humboldtii and Waimea tomatoes "wild" as these two are S. Lycopersicum ?

I don't know their history. I suspect that they are inbred varieties that carry a wild name.

I suspect that the cheesmanae and pimpinelifolium are also inbred varieties, because the species tend heavily towards inbreeding, and people have inadvertently selected for closed flowers that promote inbreeding and loss of diversity. Nevertheless, they might provide useful traits not commonly found in domesticated tomatoes.

Flowers that facilitate out-crossing are my highest priority trait in tomatoes. I didn't find enough of that in the red-fruited tomatoes, which is why I imported genetics from the green-fruited wild species.

Joseph, are the seeds for any of your tomatoes available in Europe? Would love to have some of those (facultative) outcrossing traits in the population, but it'd feel a bit silly to start from scratch with all the same wild species you used, considering that you did that work already...

Do pimpinellifolium and cheesmaniae typically have flowers as closed as the domestic types? We had one plant flowering last year that was either pimpinellifolium or cheesmaniae, and I seem to remember that the stigmata looked somewhat exserted (but I might be wrong). What about galapagense?

My promiscuous tomato seeds did get to Europe, some years ago before fear-of-the-other got so strong.

Some varieties of cheesmanae and pimpinelifolium have open flowers, as do some domestic varieties, especially among the cherry tomatoes and beefsteaks.

Joseph Lofthouse wrote:My promiscuous tomato seeds did get to Europe, some years ago before fear-of-the-other got so strong.

Some varieties of cheesmanae and pimpinelifolium have open flowers, as do some domestic varieties, especially among the cherry tomatoes and beefsteaks.

I am looking for someone traveling to bring seeds to the EU, but I do not want any trouble. I did receive your landrace tomatillos.

Nancy Reading wrote:Have you a project thread, or is it too early yet?

Now there is one: https://permies.com/t/269844/Northern-oceanic-tomatoes