Septoria.. and breeding for tolerance

[DarJones]

I looked up the genetics of Septoria tolerance and dug around on TGRC to find that they have exactly 2 accessions listed with tolerance. I've ordered LA1800 and LA3126 which should give me a start on some tolerant genetics. Unfortunately, this particular gene is a very weak form of septoria tolerance.

I also found the below article re some research at Cornell:

Martha Mutschler, Darlene DeJong, Brian Leckie, Dept. of Plant Breeding and Genetics, Cornell University
The Cornell tomato breeding programs have a special focus on control of multiple diseases and insect pests of tomato. The work leads to the development and release of germplasm or lines with superior resistance, as well as new methodologies (i.e. assays or PCR markers linked to resistance genes).
One tomato projects is focused on combined control of the three defoliating diseases of tomato: late blight, early blight, and Septoria leaf spot. Germplasm with genetic controls for early blight and late blight have been released. More recently, a strong source of tolerance to Septoria leaf spot has been characterize and is being transferred into a tomato background that possesses genetic control of late blight and early blight. We anticipate confirming germplasm possessing genetic control of all three diseases by the end of the 2009 growing season. This combination of genetic controls targets all three major foliar pathogens, allowing extreme reduction in the use of fungicides in NE tomato projection, and facilitating NE organic tomato production. This project involves cooperation with Tom Zitter (Plant Pathology) and Chuck Bornt (Cornell Coop. Ext) to facilitate the identification of the best supplemental sprays to use with triple resistant germplasm, to provide superior plant protection with minimal environmental impact.

Just curious if anyone else is interested in Septoria control.

DarJones

[frogsleap farm]

Darrel - There's a 1993 paper by Poysa and Tu (google for reference) I think is the definitive paper on resistance within Lycopersicon spp. They find significant resistance in a few hirsutum and peruvianum accessions and one pimpinellifolium. I've struck out on the pimp. but understand that Martha et.al are working with Poysa hybrids for the Cornell source of resistance. I've had no luck with the TGRC or PI lines with reported tolerance. I've had some success with lines selected over several generations, let me know if you want to collaborate

[Tom Wagner]

Too late for this year but for next year here are some links that may aid someone wanting to introgress Septoria res. into cultivated lines.




May/June 2010 www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162010000300012&lng=en&nrm=iso&tlng=en

Five new sources with high levels of resistance were found in S. peruvianum accessions (PI-306811, CNPH-1036, LA-1910, LA-1984 and LA-2744). One accession derived from an interspecific cross between S. lycopersicum and S. peruvianum was also found to be highly resistant and might be useful to introgress resistance factors from this wild species into cultivated tomato germplasm. However, additional breeding efforts will be necessary to introgress into the cultivated tomato the resistance factors identified in other S. peruvianum accessions due to the presence of natural crossing barriers between the two species.

Key words: breeding, disease control, septoria leaf spot

PI 422397
Solanum pimpinellifolium L. SOLANACEAE

Donated from: Ecuador
Selected as a variant from PI 365899. Resistant to Septoria lycopersici.

I have too many irons in the fire to effectively work on Septoria. i can only work with less than 5% of my material per year and with the huge number of my tomatoes still languishing in the greenhouse, I know I try to do too much. This year it was too much rain all spring until summer to get stuff planted.

I would guess that a good tomato that resists Septoria with the Se gene is in the works to use for further breeding.

[DarJones]

Eva Purple Ball and Burgundy Traveler have significant levels of Septoria tolerance in my garden. That is out of about 300 different varieties.

I've contacted TGRC to order some accessions with tolerance but they are S Lycopersicon which means it will be weak at best.

I am not equipped to make crosses with Peruvianum stock.

DarJones

[DarJones]

Digging around on the internet and came up with this thesis which is very enlightening re the breeding of Mountain Magic from NCSU.

www.lib.ncsu.edu/theses/available/etd-06042003-073908/unrestricted/etd.pdf

I'm working on a source of seed that has septoria tolerance from one of the S. Peruvianum lines at Cornell. Give me a while. I'll come up with some breeding stock yet. meantime, I plan to cross Eva Purple Ball with Brandywine and Daniels in an attempt to produce a better flavored tomato with a small amount of Septoria tolerance.

DarJones