Funding Blight Resistance Breeding in Heirloom Tomatoes

[William S.]

I just noticed the 2019 seed listing for Carol Deppe's Fertile Valley Seeds is up and out. Cool!

In the catalogue Carol asks for help funding her breeding work. Specifically she mentions late blight resistence breeding for heirloom tomatoes. She says we should expect serious blight problems in our heirlooms in 5 to 10 years because the multiple strains are coming which will lead to new strains and overwintering. This 5 to 10 year estimate is bold for a scientist.

Wonder if this could be crowd funded?

I've realized I need to do the same for my own favorite tomato varieties and breeding projects. Would be cool to be able to genetically test our materials for resistance genes. That's one of the things Carol wants funding for. Even the wild tomato material some of us are working with which seems to have resistance based on reports from blight stricken gardeners might have some of these known resistance genes, would be interesting to have it tested. 

[Joseph Lofthouse]

My reading of Raul Robinson's Return To Resistance, would seem to indicate that the way forward may be to eliminate the known resistance genes from the population, so that resistance can  be built up from a multitude of QTL traits, instead of depending on one "resistance" allele.

I am writing up instructions for Blight Tolerance Trials. What I really want to ask for, is that seeds be saved from those plants that are affected by the blight, but still manage to produce seeds. But that's too complicated to fit onto the label of a seed packet, so I'm asking for seeds back from anything that thrives in a garden where blight kills the domestic tomatoes, and that has promiscuous flowers, which I am defining as any of the following: Anthers not connected to each other. The style is plainly visible. The anther cone is wide open at the tip rather than constricted.

[William S.]

I wonder though if it is not the single gene traits but the way we use them.

 So take Iron Lady which is homozygous for three of these traits.

That's cool becase we can cross any tomato to Iron Lady and our resulting cross is going to get all three traits.

I wonder though if we really want to mimic the professionals and put all three traits in everything. Three traits are harder to overcome than one, but once done the same strain of blight can attack them all. If we have instead a variable population where plants have 0, 1, 2, or 3 of the traits and they might be homozygous or heterozygous I feel like that might be more representative of how these traits interact with blight in wild populations. It takes lots of strains of blight to interact with a variable population. It only takes one perfect strain of blight to wipe out a uniform population.

Let's suppose we wanted to use both known single trait based blight resistance and unknown possibly QTL resistance from wild populations. Suppose we did this by crossing Iron Lady X the multiple individuals of the Neandermato Solanum habrochaites population Joseph developed and taking it to the F2, that population would have whatever resistance genes the Neandermato wild tomato gene pool has plus the three single traits and they would segregate out into a wide variety of combinations. Blight interacting with this hypothetical population should have a pretty hard time adapting right? Of course that population would need to be selected for flavor by someone further south and further downhill than either Joseph or myself where Iron Lady grows well and where blight is already pretty intense.

To work for my purposes short seasonality has to be in the mix.

So the shortest season tomato I know of is Tim Peter's Sweet Cherriette. Though under intense torture in my 2017 garden several other tomatoes tied with it. But for simplicities sake let's say Sweet Cherriette. So for me bringing the blight resistance genes to short season gardeners has a high priority. So I could do something like Sweet Cherriette X Iron Lady AND Sweet Cherriette X Neandermato. Bring them both to the F2 without selection and mail half to someone with blight and put half in the freezer for when blight hits here. Or, just freeze a sample but keep some to work with and have it tested periodically for resistance genes.

Though another question and this might be for people who already have serious blight problems especially multiple breeding strains. How hard is it to work with old heirloom strains once the blight gets really bad?

5 to 10 years isn't much time but say it's five years. I could make two crosses a year and have my top 10 favorite varieties crossed up with resistant strains at least to the F1 and some of them grown out to the F2. Then once the blight hit I would have lots of F2 populations to select from and the blight would do alot of the selection work for me.

[reed]

My most blight tolerant tomato aside from some crossed up currents is one I call "Hoosier Rose" a dehybridized version of the commercial F1 "Red Rose". It is a cross between Brandywine and Rutgers, it segregated into normal and potato leaf versions, the best one "Hoosier Rose" has lobed green shoulders and is also the best flavored. It's flowers are semi-open, that is open enough to be attractive to the micro-bees.

The original F1 was not advertised as having any special blight tolerance, having none that I know of the blight resistant genes but it's descendants are  more resistant  than any I'v tried that are advertised as such. How can that be?

Two others that hold on better than most are an heirloom called Mr. Stripy and one I call Utah Heart, from a mix of Joseph's seeds. They also have semi open flowers and I pant them all together.

Interestingly an old local heirloom I grew for many years gets diseased so bad I stopped growing it. it used to be my primary juice tomato, now replaced by Utah Heart.

[Ocimum]

...
so I'm asking for seeds back from anything that thrives in a garden where blight kills the domestic tomatoes,
...

Don't you think you will import all the strains of Phytophtora into your garden if you manage it that way?

https://apsjournals.apsnet.org/doi/abs/10.1094/PHYTO.2001.91.11.1074

[William S.]

Quote and link from Carol:

http://www.caroldeppe.com/Donate.html

"believe that because of changes in late blight lines, it's going to become impossible to grow all heirloom tomatoes outdoors almost everywhere in North America within the next 5 to 10 years. None of the heirlooms have adequate defenses against late blight. There are commercial late blight resistant varieties produced by university breeders and big seed companies. But these are all in the form of hybrids, not open pollinated varieties. Worse yet, they pretty much all taste awful. They are bred to have uniform gorgeous color, which requires the u gene (uniform shoulders). The u gene actually causes sugar content and aromatics (flavor) to drop. In addition the commercial varieties usually have tough, unpalatable skins for resistance to damage in handling and shipping, and additional genes associated with slow ripening that confer longer shelf life, but also destroy flavor. That is not what most gardeners want to grow and eat.


I've begun a major project that involves crossing major genetics for late blight resistance as well as resistance to other major diseases into a large repertoire of heirloom varieties. My basic plan is to cross resistant hybrids to each of a couple dozen heirlooms, backcross once to the respective heirlooms, choose the offspring that carry an appropriate repertoire of late blight and other disease resistance genes, take those to the F2, OSSI-Pledge these lots as breeding material, then distribute that material far and wide for hundreds of gardeners and farmers and seed companies to use to select hundreds of new varieties of heirloom-quality open-pollinated OSSI-Pledged tomato varieties with late blight and other disease resistance combined with heirloom-quality flavor. I hope in this fashion that we can replace all the current heirlooms with equally delicious late blight resistant versions before the late blight situation gets so bad that our current heirlooms become ungrowable. This project is going to require major resources in land and labor. In addition, the step of "choosing the offspring that carry an appropriate repertoire of late blight and other disease resistant genes" from which to get the F2s to distribute will involve marker assisted selection. That alone will require several thousand dollars in lab fees per year for a number of years. However, the result of this project should be a new generation of heirloom-quality tomatoes that are not only resistant to late blight, but also carry the other important genes for disease resistance that most heirloom tomato varieties currently lack"

This sounds great to me then we can get the F2 populations we want from OSSI. We could also do similar work in parallel to Carol and pledge our own F2's to OSSI. It would be good not to duplicate. Carol is talking about doing about ~24 varieties, IF she can get the necessary funding. The marker assisted selection is a big funding need, I could cross my intended lines but could not do the Marker assisted selection. Would just need to freeze the F2 and wait for blight which would also preclude the back cross for better flavor retention.

I wonder if Carol would be open to working on specific varieties for people with favorites who have money but not time? Wonder what the cost per variety would be?

[Nicollas]

Maybe crowdfunding specific heirloom cultivars as base for the cross could work ?

[William S.]

Variety selection seems key here because being able to agree on specific varieties to undergo this treatment would make it possible to crowd fund the work but also to find collaborators to supply labor and land for specific varieties. What is more, we could bring the costs per variety down potentially if we supplied labor and land. I suspect most of us have access to land and that we are all skilled labor for this sort of thing.

[Diane Whitehead]

I find this recommendation from High Mowing Seeds odd.  Iron Lady is resistant, but protect it anyway.  Their other tomato seeds don't have this warning - instead, spraying them is suggested.

Iron Lady F1

DISEASE RESISTANCES: LB
Fight the blight with this disease resistant red slicer!
Impressive resistance to late blight, early blight, septoria and more. Fine-textured fruit is both dense and juicy with good tomato flavor. Must be planted away from other tomatoes to prevent early blight transmission. From our collaboration with Cornell University and North Carolina State University.

[Joseph Lofthouse]

Don't you think you will import all the strains of Phytophtora into your garden if you manage it that way?

With all the seed swapping that my neighbors do with far away lands, it's only a matter of time before propagules arrive here. It is super-arid here, pretty much depriving spores of the environment they need to grow. That trend will continue for my garden, even if late blight becomes more widespread in the rest of the continent.

Late blight has become established in eastern Washington, and it's common for storms to blow right through there on their way to my place. Plenty of opportunity to spread late blight. In the 2015 growing season, there was an outbreak only 2 counties away, but it hasn't returned since.

Any suggestions on seed-sanitation counter measures that might be appropriate? For example, would freezing kill spores in/on seeds? Would dehydration?

Edit to add: New thread created for tomato seed sanitation.

 

[William S.]

I find this recommendation from High Mowing Seeds odd.  Iron Lady is resistant, but protect it anyway.  Their other tomato seeds don't have this warning - instead, spraying them is suggested.

Iron Lady F1

DISEASE RESISTANCES: LB
Fight the blight with this disease resistant red slicer!
Impressive resistance to late blight, early blight, septoria and more. Fine-textured fruit is both dense and juicy with good tomato flavor. Must be planted away from other tomatoes to prevent early blight transmission. From our collaboration with Cornell University and North Carolina State University.

we should ask them why? I sent them a message.

[reed]

Can hardly imagine ya'll don't already know about this but just in case.
Sustainable Agriculture Research Grants https://www.sare.org/Grants.

[nathanp]

we should ask them why? I sent them a message.

It is possible the concern is that the seed could carry the oocytes and you would not notice because the plant is resistant.  LB could have been present and not noticed it on Iron Lady.

[William S.]

It is possible the concern is that the seed could carry the oocytes and you would not notice because the plant is resistant.  LB could have been present and not noticed it on Iron Lady.

It is possible the concern is that the seed could carry the oocytes and you would not notice because the plant is resistant.  LB could have been present and not noticed it on Iron Lady.

The original quote from the company- keeping it separate is for the early blight as I understand it.

[Diane Whitehead]

It says it is resistant to both kinds.  -  " Impressive resistance to late blight, early blight,"