Breeding for Late Blight Resistant Tomatoes

[William S.]

I got a bonus packet of Geranium Kiss in a seed order today from J & L gardens. Last night I was rereading Carol's book and it is one she mentioned as being bred by Alan Kapuler and believed to have unknown late blight resistance supposedly from Lycopersicon humboldtii a taxon that has been lumped back into probably domestic tomatoes would be my guess. 60 DTM and pointy ends though so that is something that has a reasonable chance of doing well here.

[William S.]

Seems like Skykomish x Galahad F1 would work well also. I don't think we can get Primabella easily in the United States.

Legend x Galahad F1 should also work well. Carol Deppe says in her book that Legend is PH2 homozygous.

[William S.]

Ordered Galahad F1, Lizzano F1, and Purple Zebra F1 today from territorial. I went to visit family and ended up driving right past them for a job interview on a day they were closed! Timing wasn't right yet for 2022 seed racks in stores out there either! Nows the time for seed offerings.

https://eorganic.org/node/10822

Looking at this eorganic arcticle and going through my collection including recent acquisitions it seems like my late blight resistant collection might now include:

Skykomish
Iron Lady F1 and F2
Geranium Kiss-new
Stupice
Tigerella-new
Yellow Pear
Brandywine-new


Galahad F1
Lizzano F1
Purple Zebra F1
Cloudy Day F1

I don't expect much resistance from anything that doesn't have PH2 and PH3 but it is interesting to know that a few of the heirlooms are already known for small amounts of resistance. Given that my collection includes Solanum pimpinillifolium, Solanum habrochaites, Solanum pennellii, Solanum arcanum, Solanum galapagense, Solanum cheesemanii, and Solanum peruvianum as well as hybrids with habrochaites and pennellii I imagine there might be the possibility of some other resistance in there somewhere- actually I have a new strain of habrochaites... If I ended up moving to a more commonly infested area for teaching work it would be interesting to see what survived best. Or if one of the currently very rare late blight years hit my valley like it did in 2010 near here and 2015 near Bozeman MT.

[Tim DH]

Does anyone happen to know what the nature of Blight resistance in Stupice is? Our current choice of breeding material seems to be PH2, PH3 and Other. I'd be interested in increasing my sources of 'Other'!

[William S.]

Stupice is "other" but according to this https://blogs.cornell.edu/hort/2010/04/12/avoid-the-late-blight-blues/

It is two notches below Matt's wild cherry, yellow current, and yellow pear.

It could be that there is a PH6, PH7, and PH8 etc. out in the world somewhere. It could be that no one who is willing to share the info has shelled out to test some of the "other" types.

I think Carol wrote about her love of Stupice as an early that tastes good. I would think a reasoned course of action would be too cross Stupice and the other "other" resistance varieties with Ph2 and PH3 varieties. Maybe we would end up with some resistant varieties or even just open-source hybrids that would have a little extra ability to deal with late blight.

[Nicollas]

I think there are some major dominant genes like Ph2 or Ph3 but for the most part LB resistance is multiple QTL and i guess this is the case of some heirlooms

[Roland]

Stupice do not show enough resistance in Netherlands.

[William S.]

That makes sense if it is a third ranked tier in the article I linked. Have you tried any of the other heirloom types with "other" resistance Roland?

[Roland]

Red Pearl in the verry wet 2021 year was not strong enough
Matt’s Wild Cherry good resistance
Mountain Magic verry good resistance

Rote Murmel was disapointing in 2021

[William S.]

I have been hearing good things about Matt's Wild Cherry for a long time now. I should probably put it on my wish list. It is pretty widely available.

[nathanp]

I have been hearing good things about Matt's Wild Cherry for a long time now. I should probably put it on my wish list. It is pretty widely available.

There are obviously other mechanisms for resistance other than Ph2, Ph3, and Ph5, they are just not understood or studied.  Matt's Wild Cherry may have one, as is also likely that some of Tom Wagner's lines do since they tested for greater resistance than could be expected with only Ph2 in that study referenced earlier.

Including tomatoes such as those probably makes sense for someone developing a breeding population then making selections out of it for best resistance.

A few others noted as having resistance out of traditional heirlooms are Wapsipinicon Pink and Pruden's Purple. 

[Nicollas]

About Purple Zebra F1:

Purple Zebra tomato is a fun new addition to striped tomatoes, producing tomatoes that are rich with complex flavors and a moderately firm texture. Dark red fruits with green stripes and a deep mahogany red interior do not produce muddy coloration like other tomatoes of this type. The taste is sweet and acidic leaning to sweet. Overall, this tomato has a better taste and thinner skin than comparisons with excellent disease resistance. Judges in the know say this is a very marketable fruit for farmers’ market growers. High disease resistance to ToMV, Verticillium Wilt Va/Vd, Fusarium Wilt Race 1, Leaf Mold A-E, Late Blight PH2/PH3, and intermediate resistance to TYLCV and TSWV.

“Flavor is rich, deep-bodied, almost dessert-like. Could go with vanilla ice cream. Very unique,” commented one judge. “The fruit was beautiful inside and out. They were orangy-red with green stripes and when cut diagonally, the interior was an especially attractive, juicy red,” mentioned another judge. “Good plant habit and disease resistance,” exclaimed another.

https://www.seedquest.com/mobile.php?type=news&id_article=134694&id_region&id_category&id_crop

[William S.]

Nicollas,

I read that article! It is intriguing and Purple Zebra F1 should be an interesting variety to try. I got a message from Territorial seed that my Purple Zebra F1 seed should arrive today with Galahad F1 and Lizzano F1. It will be interesting next year to find out how they segregate. I would kind of expect the stripes to be stable and the color on Purple Zebra F1 but I doubt the precise flavor would be the same at all.

[William S.]

I got a bonus packet of Geranium Kiss in a seed order today from J & L gardens. Last night I was rereading Carol's book and it is one she mentioned as being bred by Alan Kapuler and believed to have unknown late blight resistance supposedly from Lycopersicon humboldtii a taxon that has been lumped back into probably domestic tomatoes would be my guess. 60 DTM and pointy ends though so that is something that has a reasonable chance of doing well here.

I was reading about Geranium Kiss and it is supposedly a rugose dwarf with such large heavy fruiting inflorescences that it needs staking. Weird combination. I'll probably grow it without staking and see how it does.

[ThomatoGarden]

@roland

Hello, i am Thomas i'm new here
 i'm from Germany/Münsterland near the Netherlands.

i'm very interested in your cross of Skykomish x Primabella what generation is it ?
How does it look like ?
yield ...

Greetings