2012 Septoria / Early Blight / Late Blight / High Flavor breeding thread
 

I'm starting this as a separate thread for the 2012 breeding work on Septoria, what will be grown, crosses to be tested, etc. I am starting the following for my breeding lines this year. Please note that some of these are grown for disease screening, some because I already know they are disease tolerant, and some because they have very high flavor potential. I have plenty of other lines going into my main garden including others that are now stable and need only to multiply seed.

LA1800, LA3126, LA4442, These three have known disease tolerance


Blueberry Sugar, RG Brandywine X F2, Oval Paste F2, P20 Heart, Plum Lucky These are flavor and early/late blight selections


LA2904, LA2915, LA2934, LA2974, LA2982, LA2983, LA3161, LA3859, LA4138, LA1994 (S. Pimpinellifolium, septoria screening)

LA0373, LA0443, LA0722, LA1269, LA1582, LA2093, LA2533, LA2833, LA2836, LA2851, LA2854, LA2866 (S. Pimpinellifolium, septoria screening)

LA0716, LA1926 (S. Pennelli, disease screening)


Last year I did a bulk growout of the TGRC S. Pimpinellifolium core collection and screened for disease resistance. If you compare last years results with this years seed planting, you will see that the most interesting of the varieties from last year are being repeated. When I went through the list and compared geographic origin with other accessions in TGRC, I found that the most disease tolerant tended to come from specific regions of northern Peru and a few from extreme southern Peru and northern Chile. I carefully screened the rest of the TGRC collection and picked several more lines from these regions for this year. In other words, if an area gave high levels of disease tolerance, I am growing more accessions from those areas in hopes to find more general disease tolerance genes.



DarJones

[QUOTE=Fusion_power;259418] I carefully screened the rest of the TGRC collection and picked several more lines from these regions for this year. In other words, if an area gave high levels of disease tolerance, I am growing more accessions from those areas in hopes to find more general disease tolerance genes.

DarJones[/QUOTE]

Should be interesting to follow along this thread - hope you'll post some pics for us when the time comes.

Patrina

Tag,

This is interesting. These will eventually result in a variety or varieties that will be an Open Pollen type? It would be very cool to eventually have an Heirloom variety that meets or beats hybrids at their own games! :)

Gary

I am to the point of giving up with the Septoria, 3 years running :P

Where can I get a strain resistant to the disease? Do you have a supplier for seed?

I am currently looking at 30 plants being choked to death by it.

I am trying a Better boy hybrid now and have 4" seedlings in the ground.. but I'm not hopeful.

Any sources for resistant seeds would be great!

-Mike

Mus, there are no available varieties with high levels of septoria tolerance. Some significant work was done to introgress tolerance from S. Peruvianum about 20 years ago and some breeding work is ongoing in at least one program at Cornell (Martha Mutschler-Chu). The ongoing problem is that most of the tolerance genes are recessive and linkage involving other tolerance genes limits potential to stack genes. You can get septoria tolerance, but if you do, you lose tolerance to one or more other diseases.

My best suggestion is to get some of the tomatoes from Randy Gardner's breeding work. I should be able to supply quite a bit of R.G. Bold Red next year. They are only moderately tolerant to septoria, but that is a big difference from being totally susceptible like most heirloom and commercial varieties.

DarJones

Excellent Info! Thanks Fusion!

-Mike

Several of us were working with septoria tolerance a while back, but no good tests were done. I've been working with early blight here in New Mexico where septoria is not endemic. The hirsutum crosses have done very well, though part of that may be due to the remarkable degree of hybrid vigor. The peruvianum crosses, though strong plants, have a number of undesirable traits. I hope Dar is right and other progress is being made out there.
Lee

Good luck Darrel, this is a very ambitious project. I really like your well thought out research plan.

Good luck with this project Dar, and when you get plants ready for sale that are septoria tolerant, I'll be first in line to buy some :). Last year it stripped every single plant bare. This year has been drier than usual, but one of my Legend plants is really getting hit hard, even with the preventative spraying I began a while back. It is not only on the leaves, but the stems are becoming covered with the black specks. I even found one green tomato with teeny little specks on it, and I've never seen that before. Thankfully so far it is just one plant, but that doesn't mean the others in the area won't start as well.

Please keep us posted!

For some late night reading re septoria and late blight tolerant tomatoes.

[url]http://repository.lib.ncsu.edu/ir/bitstream/1840.16/7002/1/etd.pdf[/url]

DarJones

I've been running some tests on R.G. Bold Red which is a line I am working to stabilize from some of Randy Gardner's work. I decided to try to figure out why this line is highly tolerant of Late Blight. Long story short, I cut several tomatoes in half and placed them in a tray in a shaded area but where fungal growth should be rampant. Ordinary tomatoes were covered with a white film within 24 hours. The R.G. Bold Red did not become covered with fungal film for 3 days and even then, it was not a heavy growth.

This is NOT a definitive test, but does suggest that this line of tomatoes may be producing a chemical that suppresses fungal growth.

If you could synthesize this fungal growth suppressor, it might be possible to convert it into a spray. That leads to a lot of speculation about being able to spray tomatoes with a natural tomato chemical that would prevent infection with late blight! The only weakness I see is that this chemical appears to break down in about 3 days. But if it were absorbed through the leaves, it might be a highly effective way to protect tomato plants.

If you want to read about another fungal suppressor, look up Strobularin which is made from mushrooms.

DarJones

[QUOTE=Fusion_power;288984]For some late night reading re septoria and late blight tolerant tomatoes.

[URL]http://repository.lib.ncsu.edu/ir/bitstream/1840.16/7002/1/etd.pdf[/URL]

DarJones[/QUOTE]

Dar...seems when you click this http you get an internal server message at NCSU. If one searches septoria leaf spot there appears various articles on the subject. Not sure which one you are referring to.

Ken, the link works for me. It is probable the server was down for maintenance when you tried to access the file.

DarJones

I was able to get the study up on my screen. I think no matter what I do, because I live in a humid area, and in particular, my little microclimate of living on a lake, it is even more humid here, I am going to always have to deal with Septoria. Even in the heat waves we have had with no rain, and I do not overhead water, Septoria strikes! I don't compost leaves or leave refuse in the garden, but it seems to always be there, lurking and waiting.

Where my sister lives, there is no lake and she sprays water overhead on the tomatoes, and she has very little Septoria. go figure !

It's working now Dar. Thanks.