Breeding for Late Blight Resistant Tomatoes

[William Schlegel]

https://earthworkseeds.com/Tomatoes/

Amongst Earthworkseeds tomatoes it looks like Damsal F1 has far fewer resistances than Galahad F1.

The fact sheets are interesting. Both tomatoes have three resistances to nematodes.

[ThomatoGarden]

Galahad is an interesting variety, i think Roland knows more about it, but its determinant.
Arjan sent me some Damsel f1 seeds, so i will be able to report if its resistant here in Europe.

This winter i will cross a bit more to taste and not only resistance.
- 2 x Primabella
- 1 x Wasipicon peach
- 1 x Giant of Siebenbürgen
- 1 x Siberian Tiger
- 1 x Rondobella
the plants are already growing nice.


 Primabella x Wasipicon peach   Resistence + taste + colour
 Primabella x Giant of Siebenbürgen   good Resistence + vigor
 Primabella x Siberian Tiger  Resistence + taste
 Rondobella x Sibirian Tiger    Resistence + taste
 Rondobella x Wasipicon peach   Resistence + taste + colour
 Rondobella x Giant of Siebenbürgen   good Resistence + taste + size + vigor


 Rondobella x Sibirian Tiger may be a good one for back crosing taste wise.

Size of plants atm.

Rondobella, Giant of siebenburgen, Wasipicon peach  15cm
Siberian tiger                                      13cm
Primabella                                          10cm

Allways interesting that Primabella starts so slow.

Hope i will be succesful with this crossings.

I sorted out Sunviva x Vivagrande for outside tests cause of cracking, but in Greenhouse it could be nice.
If crossed with Ruhtje, Cerise red or even Campari F3 it would be something.

BtW: I found a nice tasty vigourous Campari F3 this year if anyone is interested i can send seeds.

[reed]

Galahad did not perform well in my garden this year. Production was poor, disease tolerance not the best and flavor was very lacking compared to what I expect. Hot Streak F1 was much better in all ways. I'm growing F2 of the HS next year but not Galahad.

[Roland]

Hot streak F1 resistance:
Late Blight
Gray Leaf Spot
Verticillium Wilt (High)
Fusarium Wilt races 1–2 (High)
Tomato Spotted Wilt Virus (High)

Fusarium Crown and Root Rot (High)
Tomato Mosaic Virus (High)
Resistant to Leaf Molds A-E (High)


Galahad F1 resistance:
 Late Blight (stronger as Hot Streak)
 Gray Leaf Spot (Sl)
 Gray Leaf Spot (Ss)
 Verticillium Wilt (Va: 1)
 Verticillium Wilt (Vd: 1)
 Fusarium Wilt (Fol: 1-3)
 Tomato Spotted Wilt (TSWV)
 Root-knot Nematode (Ma)
 Root-knot Nematode (Mi)
 Root-knot Nematode (Mj)

So it seems Hot Streak have more resistance for:
Fusarium Crown and Root Rot (High)
Tomato Mosaic Virus (High)
Resistant to Leaf Molds A-E (High)

[William Schlegel]

So it seems Hot Streak have more resistance for:
Fusarium Crown and Root Rot (High)
Tomato Mosaic Virus (High)
Resistant to Leaf Molds A-E (High)

That seems like an interesting analysis. If it is resistances that cause the good performance of Hot Streak for Reed than one or more of those three might be the key difference for him between those two varieties. Then I would be interested to know if any of his old standbys by happenstance have good resistance to those diseases?

I have to admit that neither Galahad nor purple zebra are standouts in my garden but I don't think I have any severe tomato disease. In theory the root knot resistance should help in the old fenced garden which has some perhaps due to the sand addition I did there. Apparently root knots are worse in sandy soils.

[reed]

I don't think I'll ever know any specific reason why a tomato does good or bad in my garden. My measure of it is a bit different from what others might consider because flavor is really important too. Actually, production and flavor are the most important of all. If I get good tasting tomatoes anyway, I don't care if the plant had disease issues. And I don't know any specific disease issues. I've been growing tomatoes in the same little spot for nearly thirty years and have never bothered with trying to eliminate disease by disposing of sick vines or anything else like that. I figure by now if there is a tomato disease that lives in soil or on last year's vines then it's here. This was a droughty year too and I didn't water so on top of any other issues the plants had to deal with that.


Of my old standbys, Hoosier Rose, Utha Heart, Cherokee Purple, Mr. Stripey and of course the pimp collection held up fine as usual although I expect even they, would have done better with a little extra water.

Of the new ones only Hot Streak came though well to have a for sure place in the garden next year. Its foliage had pretty noticeable brown curling leaves, probably as bad as Galahad was but unlike Galahad it made lots of good tasting tomatoes. Utha Heart does that too. It usually makes two harvests, an early smaller one and a later bigger one but by the time the second one is ripening good the plants themselves except for the fruit, usually look kind of bad. Of all my tomatoes the one most likely to still have full lush foliage all season long is Hoosier Rose. 

If I looked at just my oldest ones that I've had for thirty years or more I would think they had just adapted to my garden, but that's not the case because I've only had Hoosier Rose for maybe ten years, and it did good the first year or I wouldn't have kept it. I only got Willard Win three years ago and it's better except for flavor than my oldest one, Mr. Stripy and it's not far behind on flavor.

I'm still convinced there is some correlation between beefsteak tomatoes originating along the Appalachian Mountains, especially the more southern parts and if a tomato will do well for me. But that's not a sure thing either. I tried one this year called Brandywine OTV that I was excited about based on its origin and description, but it was as bad as Galahad.   




 

[Roland]

It is not entirely clear to me yet.
Galahad's fruits were not tasty but he produced?
Or Galahad produced no fruit?

I know that the F2 Galahad contains plants with extremely tasty fruits.
Maybe Damsel (the half-sister of Galahad) is a good one for you because many people like the taste of Damsel F1 better than Galahad F1.

[reed]

Galahad did produce some good-looking fruits, but only a few and they did not taste good. Interesting some of the F2 might taste better but I have limited space and have to combine my selection trials with proven producers. Hot Streak F1 was so much better than Galahad F1, I figure chances in the F2 are better with it.

[William Schlegel]

I received LA1269 a Solanum pimpinellifolium from Peru and I think the notes said it was the source of PH3 in a seed trade last winter. I already had PI 270443 the source of PH5. It strikes me that working with these original source wild strains has some value and I like the idea of including new wild genetics in more tomatoes. Even from a source like LA1269 which if it is indeed the source of PH3 it has obviously been used heavily for that introgression- there may be a lot of gene variants left on the cutting room floor so to speak that were bred out. The introgressions do tend to be quite large- but still a lot gets bred out when you only want the introgression. One thought about those is also this: You could cross a few currant tomato accessions together and register the resulting new material as breeding stock with OSSI. Might be an interesting way to protect some germplasm and still have it in a somewhat concentrated form. Or alternatively- create some novel but high percentage current tomato tiny cherry tomatoes with something like 3/4 or higher wild genetics. I have some 50% wild currant crosses that are already segregating back to blue bicolor. Crossed to currant again and they would be 3/4 current and then some of those would segregate to be very small blue bicolor tomatoes in the F2. Done iteratively it could be a nice approach for late blight resistance especially for cherry and currant sized tomatoes and for currant sized tomatoes it would expand a size class with relatively few color offerings and limited variety distinctiveness.

[William Schlegel]

https://www.etsy.com/listing/1827261935/marchenengel-aka-fairy-tale-angel-tomato?

https://heritageseedmarket.com/index.php/product/fairy-tale-forest-marchenwald/

https://bountyhunterseeds.com/product/marchenwald-rl-tomato/

https://bountyhunterseeds.com/product/marchenwald-pl-tomato/

The OSS Marchengel and Marchenwald seem to have made it to the US. They seem to combine anthocyanin and resistance based on the OSS descriptions.

https://opensourceseeds.org/en/seed/tomato-m%C3%A4rchenengel

https://opensourceseeds.org/en/seed/tomato-m%C3%A4rchenwald

Has anyone grown them in a late blight prone area or does anyone know which resistance genes they have?

[Roland]

In this study the heirloom varieties Matt's Wild Cherry, Lemon Drop, and Mr. Stripey show very good resistance for Phytophthora Us23, comparable with ph2+ph3 homozygous.

https://usablight.org/wp-content/uploads/2018/10/Hansen-Differential-susceptibility-of-39-tomato-varieties-to-Phytophthora-infestans-clonal-lineage-US-23.pdf

Has a follow-up study been conducted in which the resistant QTLs of these varieties have been investigated?

[reed]

Mr. Stripey has been a favorite of mine for decades. It is one of two that William did some crosses for me with. I'm becoming more convinced that not just it but many (but not all) of the so-called beefsteak tomatoes kept as heirlooms in the eastern US for a long time may have some overlooked qualities. I thought it was just regional adaptation but maybe it is something genetic as well.

From what I understand Brad or XH9 is just a cross between a short season domestic from Russia called Jagodka and another beefsteak called Hillbilly, which is very similar to Mr. Stripey. Three years ago, I found another one that rivals Mr. Stripey called Willard Winn. It is shorter season and more productive than Mr. Stripey and lot more so than Hillbilly.

If I was more skilled at such things and knew where to get Jagodka seeds I would try recreating HX9 by crossing Jagodka with Willard Wynn instead of Hillbilly. I think it might yield some still more productive and shorter season tomatoes. I wonder what direction that cross was done in.

Sounds like more trouble than it's worth though because based on the F1 grow out, I think the crosses William did with mine are going to yield all kinds of fantastic tomatoes already.

[William Schlegel]

Big Hill is the new name for HX-9. It's descended from Joseph's strain of Jagodka x Hillbilly. Both Jagodka and Big Hill are determinate. The tomato Joseph calls Brad was sent to him from some famous tomato seed savers in Canada but it wasn't true to type so he ended up calling it Brad. Notably Brad is indeterminate. The article that Roland found points out that indeterminate tomatoes have a leg up on determinate tomatoes in Late Blight situations. That could mean that short season indeterminates (and resistant crosses thereof) like Brad might become more important for short season growers in areas where Late Blight is prevalent than the determinates. It also might mean that a determinate tomato with good genes for late blight resistance might never reach the same potential it would if it were indeterminate. Which suggests that one line of breeding for late blight resistance would be to make indeterminate crosses with any determinate resistant varieties.

It doesn't surprise me as much that Matt's Wild Cherry and Lemon Drop have resistance as it does that Mr. Stripey does. Current and Cherry tomatoes have a potentially much broader ancestry.

[Roland]

Isn't it strange that no research is being done into the QTLs of Matt's Wild Cherry, Lemon Drop and Mr. Stripey?

Surely there must have already been a study done on this?

[William Schlegel]

Isn't it strange that no research is being done into the QTLs of Matt's Wild Cherry, Lemon Drop and Mr. Stripey?

Surely there must have already been a study done on this?

I haven't found time to search but it could go either way. If it hasn't been done it may yet be research that needs to be done. Definitely seems like a interesting line of inquiry.

Seem's Matt's wild cherry is a wild Mexican accession- with Mexico being where Late Blight has maximum diversity its resistance makes sense.

https://tatianastomatobase.com/wiki/Matt%27s_Wild_Cherry

https://www.gardeningtipsandtools.com/vegetable-gardening/lemon-drop-cherry-tomatoes-a-gardeners-delight/

https://shop.seedsavers.org/lemon-drop-organic-tomato

Seems Lemon Drop was found on Snow White- could be a cross or a back mutation or a segregation back to yellow. It seems Snow White was the result of a white x yellow cross itself.
https://tatianastomatobase.com/wiki/Snow_White

Still no idea if anyone has sequenced them though but I would say it would be wrong to think of the two cherry tomatoes as simply being heirlooms. An early modern and a true Mexican cherry tomato seems more accurate .