Arthropod and Insect Resistant Tomatoes

[William Schlegel]

May have a tomato containing 1/4 LA2329 genetics getting larger it is (MMS x BH F2) x (promiscuous x LA2329 F1). Photo attached- the transplanted anther cone is still attached.

Have attempted promiscuous x LA2329, BH x LA2329, (MMS x BH F2) x (LA1410 x unknown), and MMM x LA1410 crosses in the Arthropod resistance garden. So all the different plants in there this year have had at least a attempt made at a deliberate cross. Also the MMM aka (MMS x BH) F2 potato leaf crosses are showing on average more exsertion as it gets hotter. I am also increasingly confident that 2021 gave us F1s with both LA2329 and LA1410 the habrochaites and galapagense arthropod resistance sources. Small tomatoes have formed already on the galapagenose hybrid and I see a small possibility of stripes and fuzz. I can't wait to grow the F2s and so forth!

[William Schlegel]

Made more MMM F2 x (promiscuous x LA2329) attempts with a nice blue skinned and modestly exserted MMM F2 today.

[William Schlegel]

Some of my very exciting crosses are now buried under F1 Promiscuous x LA2329 habrochaites foliage. I hope they ripen soon, and I am able to dig them out of there with the labels intact! On the plus side I see quite a bit of fruit setting on both the F1 and the pure LA2329 plants. The possibility that some of those may also be back crosses is also intriguing. This project would be greatly simplified if a high percentage LA2329 habrochaites plant would produce good tasting tomatoes. Though the possibilities in both directions are really rich right now with 50% habrochaites, 62.5% habrochaites, 31.25% habrochaites, and 81.25% habrochaites/wild all reasonably possible outcomes of this year's crossing block with LA2329, MMM F1, Promiscuous, Big Hill, and the Promiscuous x LA2329 F1's. I am simplifying a little bit because there is likely a little bit of penellii in there as well and some of the domestics come with some introgressions from additional species. Also, I have the LA1410 Solanum galapagense in the same garden. If I get a LA1410 cross a subsequent year goal will be something like (MMM x LA2329) x (MMM x LA1410).

[William Schlegel]

Got some tomatoes from LA1410 galapagense today for seed. Not many and from a lot of plants. Weird cold early season than weirdly hot late season must not be good for them. Funny I got so many fruits from just one clump last year. May still be some time though. They are bigger plants and have lots of flowers. In 30 days if not frozen they may be covered in ripe fruit.

I got the first four ripe fruits from Promiscuous x LA2329 habrochaites today. Fun. Hopefully will get lots more. The F2 should be exciting. Though I've already gotten 1/4 strength seeds back. Which are technically 3/8th wild or something like that actually.

Also got another Big Hill / HX-9 x LA2329

[Nicolas]

A thesis about trichome and insect resistance :

Defence from the wild : Specialised metabolism in tomato glandular trichomes

Studying more precisely habrochaites PI127826

[William Schlegel]

https://www.hrseeds.com/product-page/heirloom-reviews-woolly-currant-tomato

I think I already have this or similar. I worried that the two obvious hybrid plants were maybe stable hybrids. After reading the above description I am certain they were not! I also crossed the hybrids to my MMM line.

So I have 75% domestic 25% galapagense and 75% domestic 25% LA2329 habrochaites to grow in my 2023 arthropod resistance garden. I sense a 12.5% hab 12.5% galapagense cross in my future.

[Nicolas]

Development of BC3F2 Tomato Genotypes with Arthropod Resistance Introgressed from Solanum habrochaites var. hirsutum (PI127826)

[William Schlegel]

Nice article find Nicolas!

One difficulty I have that it is going to be time for in 2023 is looking for resistant offspring. I will have F2 offspring and some 75% domestic type offspring. In the article you found they infected them to test. I can't do that as I don't have the facilities or the same arthropods.

It is possible though that the Colorado potato beetle larvae will come back in the SE garden.

Also the Solanum habrochaites accession is different and from the USDA ARS GRIN system instead of TGRC.

[William Schlegel]

Derivatives of TGRC accessions are not subject to the TGRC MTA. That means I can grow and share the crosses I've made with LA2329.

[William Schlegel]

Significant challenges await this project perhaps starting this year. F2 segregation is when we ran into the most reproductive problems with the prior Solanum habrochaites project Joseph Lofthouse initiated. I think I got some F2 material clear back in 2017 and planted some 10 plants and barely got any seed back. One problem with this is that it is just possible that when searching for something specific like arthropod resistance that the plants that segregate badly could be the very plants that have the desired traits. Assuming that the desired traits haven't segregated out of my LA2329 population itself in adapting a bit to my climate (and probably loosing some genetic diversity on the way).

I suspect that the new F1s will have no problems either those that are 1/4 habrochaites or those that are 1/2. Though that just pushes the potential problems off a year to 2024 as those will be F2s then.

[AndrewB]

I've been dealing with an infestation of aphids in my grow tent this winter. But I've just realized that the wild-ish tomato I've kept alive that had those weird fruits has had no problems with the aphids. I think it has habrochiates ancestry. Smells nice for a tomato.

[William Schlegel]

I need a way to test my lines. Hadn't thought about aphids but I've been wondering how much trouble I would be in with my wife who has a bit of a plant pathologist streak if I wanted to deliberately culture and spread spider mites or white flies.

[AndrewB]

Is there anyway you could partner with a local university or some grad students from your local soil and crop sciences department?

I think that may be the best option since you have so many tomato projects now and are spread a little thin. If they could take this project and run with it then perhaps they could lead the project and you can still be involved and benefit from it. Plus you could expose them to open source plant breeding.

[William Schlegel]

Not that I know of.

Check this out though: penellii genes.

https://www.freethink.com/science/pest-resistant-tomatoes?amp=1

[AndrewB]

Very cool! Looks like we are on the right track.

The pennellii hybrid that was in my tent was not attractive to the fungus gnats or the Whiteflies that had been in there. Or the aphids.