Disease resistance testing

[Boutique Tomatoes]

Thanks for the culture offer Mark. We shall see how my efforts progress, strange to be hoping for some infected plants...

Handy that your wife is in a related field!

[carolyn137]

Originally Posted by frogsleap farm

The hero in this story is Dr. Vaino Poysa, a tomato breeder at AgCanada (now retired) who made crosses to both L. hirsutum and L. peruvianum accessions and screened progeny for Septoria resistance using the seedling screening protocol referenced earlier in this post. This "resistant" material sat around for a long time before being picked up by Dr Munchler at Cornell - from which she developed Iron Lady. I'm interested in making crosses to Iron Lady and doing a seedling pre-screen before going to my 2014 breeding nursery - which is a reliable Septoria hot bed. Unfortunately the resistance reported in Iron Lady is only effective at low innoculum loads in the field - but it appears to be the best we have so far.

Sounds good to me and I'm behind the times as to background research but had seen Iron Lady mentioned a few times.

Do you mean Martha Mutschler at Cornell? I could almost swear that at one time she was a squash breeder before she obviously switched to tomatoes.

Carolyn

[frogsleap farm]

Originally Posted by carolyn137

Sounds good to me and I'm behind the times as to background research but had seen Iron Lady mentioned a few times.

Do you mean Martha Mutschler at Cornell? I could almost swear that at one time she was a squash breeder before she obviously switched to tomatoes.

Carolyn

Yep, pardon for the spelling error on Martha's last name. Your buddy Tom Zitter is a collaborator, and I believe his daughter is now a grad student with Martha and also on the project. One of the parents in Iron Lady is from NCSU (one of Randy's lines) and combines EB/LB resistance, the other carries Septoria resistance from Poysa's program.

[carolyn137]

Originally Posted by frogsleap farm

Yep, pardon for the spelling error on Martha's last name. Your buddy Tom Zitter is a collaborator, and I believe his daughter is now a grad student with Martha and also on the project. One of the parents in Iron Lady is from NCSU (one of Randy's lines) and combines EB/LB resistance, the other carries Septoria resistance from Poysa's program.

I wouldn't call Tom a buddy but he did train the woman who was in charge of the five county area around Albany NY in tomato diseases, and that was the Cornell Coop Ext.

Early on I had observed what I named CRUD, which was a browning of the leaf margins when my plants were still in the greenhouse, the one with no sash left and birch trees growing up in it.

When the plants were put out that CRUD disappeared, but in the open greenhouse it was somewhat infective.

So she told me to contact Tom and ask his opinion. I did and he said he knew exactly what I was referring to and he thought it was an aberrant Early Blight infection but hadn't been able to prove it. And then with more discussion he brought up spraying my outside plants with EB to see how they did, but I nixed that.

The woman who was head of that Cornell Coop Ext had two interns one year so it was decided to use my field to see which foliage disease or diseases infected which varieties. So it was also suggested that I grow some F1 hybrid seedlings, which I did. Gack!

And her two interns, with her along, came I think twice a week to record the data.

And it was that summer when I learned the most about tomato diseases, mainly foliage but also some Verticillium occasionally since at that time we had no other serious soilborne diseases as there are today.

it was a great experience.

I still think Martha was involved with squash breeding and used some of Dr. Oved Schifress's germplasm.

Could I be wrong? Why not for my tomato brain cells are better than my squash brain cells.

Carolyn

[chilisauce]

For what it's worth, I will be growing Iron Lady this year. We have had heavy late blight damage in our area (chautauqua county, sw NY) in both home and commercial gardens. I am hoping one of my choices will be resistant enough to give me a full crop. Also growing Mt. Merit, Mt. Magic, Old Brooks, Plum Regal.

Great to know there is so much effort going into breeding disease resistant tomatoes! Thanks!

[Tom Wagner]

Septoria is one of those names that seldom rolls off the tongue of the average gardener. I was at the Northwest Flower and Garden event in Seattle yesterday and an exhibitor displaying specialty growing containers had a grafted tomato growing in one of his pots. I was telling my webmaster friend that the lower leaves were infected with Septoria...when the proprietor's ears perked up and came over to me to inquire what the disease was again. He said no one knew what the disease was and he had hundreds of visitors looking at the tomato plant over the last three days.

I explained the symptoms of SLS and he said that was exactly what he had experienced over the years. He asked how to get rid of it, how to avoid it...all the usual things. I told him about IRON LADY and where to buy the seed...how to spell SEPTORIA, but warned him that even Iron Lady is (at best) a temporary tolerance and would be best used as the only tomato used as to not allow highly susceptible varieties to be anywhere near it for fear of eventually contamination.

I even told him that saving the seed from Iron Lady would be a good idea just to look for homozygous seedlings for a tad better tolerance. Even though Se, the gene responsible for a bit of dominance..the best results will be from fully loaded Se/Se genotypes.

I gave him some free seeds of my SKYKOMISH and BLUE TEARS tomatoes and he thanked me by giving me a large growing container from his display to try out with a Iron Lady tomato this Spring.

Telling my webmaster friend, Rob, about all the selections of Poysa's introgressions that I have from twenty years ago that are underutilized in my accessions collections as well as many lines from Mutschler and Gardner....I thought maybe I should revisit these materials. There may be some value somewhere among the seeds.

Oh, by the way.....here is a poorly shot picture of the Septoria fungal spots from his tomato plant on display.

[Fusion_power]

It is worth mentioning that Early Blight, Septoria, Powdery Mildew, and Gray Leaf Spot are significant diseases of tomato but for which genetic tolerance is very weak. Early Blight tolerance is being selected for in the PA program by Foolad. Septoria is being brought in at Cornell. Powdery Mildew tolerance has been bred in from S. Chilense. Botrytis (gray leaf spot) tolerance can be introgressed from S. Lycopersicoides.

The problem is that we are several years away from having even one single variety that is highly tolerant to all of the above much less to also include Late Blight, Verticillium, Fusarium (1, 2, and 3), Nematodes, and TMV. What is very much needed is access to marker assisted selection by breeders outside the university and corporate programs.

DarJones

[Boutique Tomatoes]

Fusion, you've mentioned marker assisted selection for the independant breeder a few times recently. I'm curious if you know of anything 'in the pipeline' to make something like this accessible to smaller breeders?

Although I doubt it could be done cheaply enough to make it reasonable for initial screening of a hundred or more plants like what I was thinking of doing, I could see it done with some of the lines selected from a first screening to verify resistance.

[frogsleap farm]

Originally Posted by marktutt

Fusion, you've mentioned marker assisted selection for the independant breeder a few times recently. I'm curious if you know of anything 'in the pipeline' to make something like this accessible to smaller breeders?

Although I doubt it could be done cheaply enough to make it reasonable for initial screening of a hundred or more plants like what I was thinking of doing, I could see it done with some of the lines selected from a first screening to verify resistance.

There are various for profit labs that offer this service, each offering marker analysis for a handful of disease resistance markers - but it is expensive if you are screening a segregating population looking for plants combining multiple disease resistance markers.

[Boutique Tomatoes]

I'd seen at least one reference to a private lab offering this service but I can't seem to find it now. I remember when I looked at it before I didn't think it was a viable tool for me given the expense.

If that's still the kind of price range I don't see it being viable unless a breeder was releasing a PVP variety or developing F1 hybrids.

Now if they got it down around the cost of soil testing, that would be a different story.

[Fusion_power]

There is one lab in Salt Lake City that can do it reasonably cheap. Still would take about $5000 to screen 100 plants. I'm looking for something a lot cheaper.

There is some dna chip technology in the pipeline that can cut the cost down to about $10 per plant. It will probably be widely available within the next 5 years.

DarJones

[Boutique Tomatoes]

When it gets down to that point it will be a no-brainer. For now $5000 is a lot of seed sale revenue to put into testing for an OP line, which is why I was thinking about alternatives from before we had those options.

Thanks!

[frogsleap farm]

There is an inevitable cost of isolating DNA from each plant you want to genotype. Most medium sized labs use "kits" to do this. Cost of materials and labor are $2-5/sample in your own lab - probably double if done by a contract lab. Genotyping or identifying the presence or absence of particular markers is an additional cost, but the you are stuck with the limited range of markers available at a particular lab - which today is pretty limiting at the commercial labs. Total cost may be $10-15/plant, if the volume is high enough, but you'll have a limited set of markers. The large breeding companies can do the whole thing for $2-3/sample for a customized array of markers - putting them at a competitive advantage. I agree any such investment only makes sense when you can capture a downstream royalty to offset the expenses - which normally means hybrids.

[ChrisK]

I have no idea how much it costs but check out Data2Bio. It's an offshoot of an academic lab at IA State. They focus on larger projects and NGS but...

http://www.data2bio.com/

[frogsleap farm]

I just confirmed pricing at one of the labs - 6 markers on 200 plants = $1500; double the price if same analysis on 1000 plants.