Research Question regarding Root Knot Nematodes

Baizanator · June 25, 2012

So... after much consideration I'll be completing a second Master's Degree in Agriculture, Molecular Genetics at Tarleton State University in Stephenville, Texas. For my research we're going to be exposing several varieties to Root Knot Nematodes and then selecting the best of our strains to cross. The F1s and F2s will then be exposed accordingly and data will be collected.

We are needing to know heirloom or fertile hybrid varieties that you may have experience with that have some resistance to RKN. If you have any experience on this matter, let me know. Dr. Male, I'm especially looking for any advice you may have to offer. Seed purchase must be made ASAP as we're rolling with the initial work in August/September.

It would help if varieties were from genetically diverse strains as differing sources of resistance could be paramount to a successful cross.

This will be a greenhouse tomato.

jerryinfla · June 25, 2012

Baizanator - First Prize hybrid is the most RKN resistant tomato I've grown but I have only very limited tomato growing experience here in Florida. I have a serious RKN problem and last Fall the First Prize planted adjacent to heirlooms had no RKNs while the heirlooms were infested with them. This Spring I planted First Prize again but only among other supposedly RKN resistant hybrids. Again the First Prize had no RKNs. Big Beef hybrid and Lemon Boy hybrid showed no signs of RKNs in my Spring planting either.

Baizanator · June 25, 2012

Quote:

Originally Posted by jerryinfla

Baizanator - First Prize hybrid is the most RKN resistant tomato I've grown but I have only very limited tomato growing experience here in Florida. I have a serious RKN problem and last Fall the First Prize planted adjacent to heirlooms had no RKNs while the heirlooms were infested with them. This Spring I planted First Prize again but only among other supposedly RKN resistant hybrids. Again the First Prize had no RKNs. Big Beef hybrid and Lemon Boy hybrid showed no signs of RKNs in my Spring planting either.

Jerry,

Thanks for replying. I'll look at First Prize. I looked at Big Beef and Lemon Boy and they're showing as sterile hybrids while First Prize is not. Does anyone know if that is correct on these three?

Thanks,

Reed

**carolyn137** · June 25, 2012

We are needing to know heirloom or fertile hybrid varieties that you may have experience with that have some resistance to RKN. If you have any experience on this matter, let me know. Dr. Male, I'm especially looking for any advice you may have to offer. Seed purchase must be made ASAP as we're rolling with the initial work in August/September.

*****

Reed, I have no personal experience with RKN's b'c they aren't a problem where I've grown tomatoes, but I have done a lot of research on them for others.

First, just as with Fusarium and other non-foliage diseases, I know of no varieties that are totally resistent to any of them, the operative word being tolerant. So they have tolerance, which is different from resistance. The tomato industry introduced the term tolerance after there were some lawsuits where large scale farmers bought seeds of varieties said to be resistant, and they weren't.

A few years back I was interactring with a hybridizer from Petoseed who was stationed in FL and he explained to me the utter frustration of RKN tolerance, my word, b'c there are nematode breaking strains of RKN's that can overcome the tolerant RKN gene that had been inserted. There was more he told me that I don't remember right now.

But I might after I think about it for a while.

I'm sure those who grow in RKN infested soils, meaning those in the southern regions, will be much more helpful about naming specific varieties that they think do better than others.

Baizanator · June 25, 2012

Quote:

Originally Posted by carolyn137

We are needing to know heirloom or fertile hybrid varieties that you may have experience with that have some resistance to RKN. If you have any experience on this matter, let me know. Dr. Male, I'm especially looking for any advice you may have to offer. Seed purchase must be made ASAP as we're rolling with the initial work in August/September.

*****

Reed, I have no personal experience with RKN's b'c they aren't a problem where I've grown tomatoes, but I have done a lot of research on them for others.

First, just as with Fusarium and other non-foliage diseases, I know of no varieties that are totally resistent to any of them, the operative word being tolerant. So they have tolerance, which is different from resistance. The tomato industry introduced the term tolerance after there were some lawsuits where large scale farmers bought seeds of varieties said to be resistant, and they weren't.

A few years back I was interactring with a hybridizer from Petoseed who was stationed in FL and he explained to me the utter frustration of RKN tolerance, my word, b'c there are nematode breaking strains of RKN's that can overcome the tolerant RKN gene that had been inserted. There was more he told me that I don't remember right now.

But I might after I think about it for a while.

I'm sure those who grow in RKN infested soils, meaning those in the southern regions, will be much more helpful about naming specific varieties that they think do better than others.

Thank you. Yes, I guess I can understand the difference between tolerance and resistance. I'm hoping that by, crossing two genetically diverse strains, we can increase tolerance and field a greenhouse variety that can handle them.

Baizanator · June 25, 2012

Okay. After some research it seems as though the following varieties, while hybrids, can be used for seed saving as the seeds are not sterile.

They are:

First Prize VFFNT
Royesta FFNT
Abraham Lincoln FN
Beefmaster FVN
Cavalier VFNTA

I think I hybridize them with a non-tolerant heirloom to see if the resulting generations have increased tolerance.

Probably use a Cherokee Purple or Brandywine. If successful, the resulting plant could be a marketable hybrid.

dice · June 26, 2012

You can try Granny Cantrell:
http://t.tatianastomatobase.com:88/wiki/Granny_Cantrell

The evidence is anecdotal (one person said, and I paraphrase,
"Granny Cantrell was the only variety with no nematode
damage".) This was a Tomatoville member, I do not remember
who exactly, who had grown this cultivar among a variety of
other OP varieties outdoors in some locale where RKN is
apparently chronic in the soil.

If purchasing seeds from commercial vendors, I would source
them from multiple vendors, as any one single vendor might
have a wrong variety cataloged and inventoried under that
cultivar name. (And the person who reported the RKN tolerance
might have been wrong about which one it was, too.)

The long dtm might be an issue in commercial development. (Do
greenhouse growers want to wait that long for first production?
I am not familiar with that market, so I have no insight into that.)

Baizanator · June 26, 2012

Quote:

Originally Posted by dice

You can try Granny Cantrell:
http://t.tatianastomatobase.com:88/wiki/Granny_Cantrell

The evidence is anecdotal (one person said, and I paraphrase,
"Granny Cantrell was the only variety with no nematode
damage".) This was a Tomatoville member, I do not remember
who exactly, who had grown this cultivar among a variety of
other OP varieties outdoors in some locale where RKN is
apparently chronic in the soil.

If purchasing seeds from commercial vendors, I would source
them from multiple vendors, as any one single vendor might
have a wrong variety cataloged and inventoried under that
cultivar name. (And the person who reported the RKN tolerance
might have been wrong about which one it was, too.)

The long dtm might be an issue in commercial development. (Do
greenhouse growers want to wait that long for first production?
I am not familiar with that market, so I have no insight into that.)

The DTM might be an issue. We're looking to work something up that will mature in 65-75 days, which isn't short but it isn't 90 days either.

dice · June 26, 2012

If you cross it with some (not infertile) short-season commercial
variety that has the genes for RKN tolerance, you might be able
to work with that. (Some selections from unstable generations
will be shorter season than others.)

I would expect Granny Cantrell to have better flavor than any of those
commercial hybrids that you listed.

Baizanator · June 27, 2012

Well, had a brainstorming session with my professor today and, in order to get quicker results, we're going to do things a bit different.

We'll be planting the five hybrids above as well as four heirloom varieties with no known nematode resistance. We're going to select the most resistant from each category after inoculation and hybridize them out to the F2 stage then reinoculate and record results.

June 25, 2012	#1
Baizanator Tomatovillian™ Join Date: Apr 2012 Location: Hamilton, Texas Posts: 382	Research Question regarding Root Knot Nematodes So... after much consideration I'll be completing a second Master's Degree in Agriculture, Molecular Genetics at Tarleton State University in Stephenville, Texas. For my research we're going to be exposing several varieties to Root Knot Nematodes and then selecting the best of our strains to cross. The F1s and F2s will then be exposed accordingly and data will be collected. We are needing to know heirloom or fertile hybrid varieties that you may have experience with that have some resistance to RKN. If you have any experience on this matter, let me know. Dr. Male, I'm especially looking for any advice you may have to offer. Seed purchase must be made ASAP as we're rolling with the initial work in August/September. It would help if varieties were from genetically diverse strains as differing sources of resistance could be paramount to a successful cross. This will be a greenhouse tomato.

June 25, 2012	#2
jerryinfla Tomatovillian™ Join Date: Dec 2011 Location: Central Florida Posts: 377	Baizanator - First Prize hybrid is the most RKN resistant tomato I've grown but I have only very limited tomato growing experience here in Florida. I have a serious RKN problem and last Fall the First Prize planted adjacent to heirlooms had no RKNs while the heirlooms were infested with them. This Spring I planted First Prize again but only among other supposedly RKN resistant hybrids. Again the First Prize had no RKNs. Big Beef hybrid and Lemon Boy hybrid showed no signs of RKNs in my Spring planting either. __________________ Jerry - You only get old if you're lucky.

June 25, 2012	#4
carolyn137 Moderator Emeritus Join Date: Jan 2006 Location: Upstate NY, zone 4b/5a Posts: 21,169	We are needing to know heirloom or fertile hybrid varieties that you may have experience with that have some resistance to RKN. If you have any experience on this matter, let me know. Dr. Male, I'm especially looking for any advice you may have to offer. Seed purchase must be made ASAP as we're rolling with the initial work in August/September. ***** Reed, I have no personal experience with RKN's b'c they aren't a problem where I've grown tomatoes, but I have done a lot of research on them for others. First, just as with Fusarium and other non-foliage diseases, I know of no varieties that are totally resistent to any of them, the operative word being tolerant. So they have tolerance, which is different from resistance. The tomato industry introduced the term tolerance after there were some lawsuits where large scale farmers bought seeds of varieties said to be resistant, and they weren't. A few years back I was interactring with a hybridizer from Petoseed who was stationed in FL and he explained to me the utter frustration of RKN tolerance, my word, b'c there are nematode breaking strains of RKN's that can overcome the tolerant RKN gene that had been inserted. There was more he told me that I don't remember right now. But I might after I think about it for a while. I'm sure those who grow in RKN infested soils, meaning those in the southern regions, will be much more helpful about naming specific varieties that they think do better than others. __________________ Carolyn

June 25, 2012	#6
Baizanator Tomatovillian™ Join Date: Apr 2012 Location: Hamilton, Texas Posts: 382	Okay. After some research it seems as though the following varieties, while hybrids, can be used for seed saving as the seeds are not sterile. They are: First Prize VFFNT Royesta FFNT Abraham Lincoln FN Beefmaster FVN Cavalier VFNTA I think I hybridize them with a non-tolerant heirloom to see if the resulting generations have increased tolerance. Probably use a Cherokee Purple or Brandywine. If successful, the resulting plant could be a marketable hybrid. Last edited by Baizanator; June 25, 2012 at 04:43 PM.

June 26, 2012	#7
dice Tomatovillian™ Join Date: Jan 2007 Location: PNW Posts: 4,743	You can try Granny Cantrell: http://t.tatianastomatobase.com:88/wiki/Granny_Cantrell The evidence is anecdotal (one person said, and I paraphrase, "Granny Cantrell was the only variety with no nematode damage".) This was a Tomatoville member, I do not remember who exactly, who had grown this cultivar among a variety of other OP varieties outdoors in some locale where RKN is apparently chronic in the soil. If purchasing seeds from commercial vendors, I would source them from multiple vendors, as any one single vendor might have a wrong variety cataloged and inventoried under that cultivar name. (And the person who reported the RKN tolerance might have been wrong about which one it was, too.) The long dtm might be an issue in commercial development. (Do greenhouse growers want to wait that long for first production? I am not familiar with that market, so I have no insight into that.) __________________ -- alias

June 27, 2012	#10
Baizanator Tomatovillian™ Join Date: Apr 2012 Location: Hamilton, Texas Posts: 382	Well, had a brainstorming session with my professor today and, in order to get quicker results, we're going to do things a bit different. We'll be planting the five hybrids above as well as four heirloom varieties with no known nematode resistance. We're going to select the most resistant from each category after inoculation and hybridize them out to the F2 stage then reinoculate and record results.