Arthropod and Insect Resistant Tomatoes

[William S.]

https://m.youtube.com/watch?v=JRKSzWSPQnw

Over a year ago now I watched the above video.

This led me to request a packet of LA2329 from the Tomato Genetics Conservation Center TGRC.

Currently growing that accession a second time.

One of my primary thoughts originally is that this could make a difference for direct seeding tomatoes for cooperators that were struggling with early season mortality from mites (correction: flea beetles)

Thought I should start a dedicated thread.

[William S.]

https://m.youtube.com/watch?v=iAWbv1bwNkk
Another YouTube video I have not watched yet.

https://tgc.ifas.ufl.edu/TBRT%202018/PestR/Introgression%20of%20type%20IV%20trichomesand%20zingibereneinto%20tomato%20from%20S.%20habrochaites,%20LA2329%20Current%20status%20Synder.pdf
Pdf Garrett found recently. 

[Joseph Lofthouse]

It is flea beetles that consume the cotyledons of my tomatoes.

My short season is long enough that I could grow direct seeded tomatoes, if they survived the first few weeks after germination.

Here's the 8 plants of LA2329 that I am growing. They sure are smelly!!!

[William S.]

Last year I really loved the hairiness. I planted them in some extra clay infused soil by chance and the plants stayed small even for my garden. I don't remember smelling them. My sense of smell is not as acute as it could be. They bloomed alot. Very curious to find out if they crossed with the other habrochaites nearby last year. Assuming it's possible to tell.

Have thirty seedlings from the original packet so far and probably over one hundred from the 2020 grown seed. 

[William S.]

Last Year

[William S.]

https://m.youtube.com/watch?v=iAWbv1bwNkk
Another YouTube video I have not watched yet. Edit: watched it fast forwarded most of it. Not that interesting.

https://tgc.ifas.ufl.edu/TBRT%202018/PestR/Introgression%20of%20type%20IV%20trichomesand%20zingibereneinto%20tomato%20from%20S.%20habrochaites,%20LA2329%20Current%20status%20Synder.pdf
Pdf Garrett found recently.

https://www.actahort.org/books/944/944_1.htm
Looks interesting- just found.

https://portal.nifa.usda.gov/web/crisprojectpages/0223718-arthropod-resistance-of-lycopersicon-hirsutum-la2329-a-wild-relative-of-tomato.html
Also interesting.

Note: have 104 germinates of 2020 grown LA2329 and 30 from the original packet. I followed the intense 30 minute at 50% bleach protocol from the TGRC website which they recommend for habrochaites. This accession is germinating faster and more throughly than almost any other tomato I am growing. It's relatively cold downstairs.

[Garrett Schantz]

Second link mentioned PI 134417 having 2-Tridecanone in its leaves which can kill parasites, other insects. So figured I would do a small search.

https://www.researchgate.net/publication/7377420_Natural_Products_Repellency_and_Toxicity_of_Wild_Tomato_Leaf_Extracts_to_the_Two-Spotted_Spider_Mite_Tetranychus_urticae_Koch

Ended up finding this fun link. Seems like there are different chemicals in different accessions. Could try out multiple accessions, wouldn't want insects to adapt too quickly... The link provides even more accessions. Might be able to find related research with these. 

Lethality of extracts was mainly associated with the presence of high concentrations of 2-tridecanone; repellency of extracts was mainly associated with the presence of trans-caryophyllene. Leaf extracts of L. hirsutum f. glabratum accessions that contain significant quantities of 2-tridecanone and/or trans-caryophyllene could be useful for managing populations of spider mites, which could reduce reliance on synthetic pesticides. Zingiberene isn't mentioned here very much - it was mentioned in the other studies using LA2329 frequently.

Edit: 2-Tridecanone is mentioned once in the nifa.usda link. The actahort link doesn't contain 2-tridecanone either, could be in the full book though. Trans-caryophyllene isn't mentioned in any of the other links.

The S. habrochaites accession PI 134417 produces intermediate-chain methyl ketones in its trichome secretions. Four MKs (2-tridecanone, 2-undecanone, 2-dodecanone, 2-pentadecanone) and their mixture were screened for repellency and ability to alter fecundity of spider mites. All MKs repelled spider mites. Spray application of crude leaf extracts prepared in ethanol, average number of eggs/female mite dropped from 0.9 to 0.3 24 h after exposure a 68% reduction, suggesting that crude extracts of certain S. habrochaites accessions may possess anti-arthropod activities, and could be useful as an aid in agriculture. - nifa.usda link

Could be that some of these chemicals just weren't identified or named in LA2329 research projects.

Some other accessions that were highly repellant:
PI 134417 (No Known Plant ID) Ecuador
PI 134418 (No Known Plant ID) Ecuador
PI 251304 (LA0407) Ecuador
PI 126449 (26) Peru

Assuming that PI 134417 and PI 134418 were collected from around the same area. Could have different chemical levels? If they have no differences, there probably wouldn't be two accessions. Only one of these is from outside Ecuador.

Managed to find the LA0407 name by searching PI 251304 in the database. Helped me find this fun little PDF https://nph.onlinelibrary.wiley.com/doi/pdf/10.1111/nph.14130.

It mentions LA1777 and LA0407 introgression lines, all sorts of fun stuff. LA0407 is similar to LA2329, so this some of this research probably still fits in pretty well.

The difference here seems to be that LA0407 is Self Compatible, LA1777 is Self Incompatible.

Talks a good bit about intraspecific crosses being linked to SI, and other things.

Luckily LA2329 crosses well enough with domestics that this research isn't needed for this accession.

[William S.]

Yeah, there is so much that could be done. I'm going to stay focused on LA2329 for awhile on this project. This year mainly I hope to raise enough seed to share decent amounts with close collaborators. Also hope to see if I can plant one R18 with the LA2329 and get basically 50% LA2329 offspring that will cross back to LA2329 next year. So far only four R18 have sprouted. R18 is a selection Joseph made last year believed to have the best promiscuity. If so a single plant would have to be pollinated by the wild tomatoes and woyld probably contribute some pollen to the wild tomatoes. Also the six seeds of Joseph's habrochaites cytoplasm line have insofar not sprouted. I thought I would keep those next to the LA2329 population as well as the lone R18. Perhaps should have used bleach more widely. It's too soon yet to replant.