Which tomato has the most diverse DNA?
 

Would crossing wild species whit each other increase genetic diversity and would there be benefits? Has there been such attempts?

I have no idea but plants aren't people/animals and it is sometimes hard to make that realization.
Crossing can create hybrid vigor or create the worst of both species or strains.
With a hybrid self pollinating tomato it is a one shot deal if you cant stabilize it.
Right now I have two hybrid agave and I have no idea if the seeds from them would produce the same thing as most are just clones or collections of pups from the original cross.


Worth

[url]http://aob.oxfordjournals.org/content/100/5/1085.full.pdf+html[/url]

Speaking of "genetic diversity" within a single species/variety is an oxymoron.

It is what it is, not what it is not.

If you are saying that "species" can not be diverse, I completely disagree. There is considerable genetic diversity within species, and some species are much more diverse than others. No species is uniform genetically, except when there is only one individual left in a species.

If you are using "species" as synonymous with "true-breeding variety" that is a mis-use of the term "species"

[QUOTE=dmforcier;598536]Speaking of "genetic diversity" within a single species/variety is an oxymoron.

It is what it is, not what it is not.[/QUOTE]

Did you miss my use of the word variety?

[QUOTE=dmforcier;598562]Did you miss my use of the word variety?[/QUOTE]

I didn't miss your use of the word variety and I agree completely with Fred.

How many times have you seen me and others post to never save seeds off just one plant of a variety,better two plants,even better three plants,etc.

There are SUBTLE mutations happening all the time with almost all varieties, DNA is not static,hence,preserving the genetic diversity within a variety.

Carolyn

Yes. Your writing species/variety is incorrect. It implies that they are the same. They are not.

All varieties of tomatoes are a part of the same, single, species.


[QUOTE=dmforcier;598562]Did you miss my use of the word variety?[/QUOTE]

Oh back off. That was shorthand for "variety, a subset of species".

So, do you believe that the poster is asking which variety has the highest incidence of mutation?

If it's not that, then what does the question mean?

Anyone want decaf?:D:)):)) Jimbo

Must be late in the fall, everyone is getting grouchy. Grouchy is not impressed and wants all to keep hands off!

I'm going to give a bit better explanation. Think of a species as a set of programs that work together. Over a lot of time, those programs have been more or less optimized to continue producing the life form they code for. Cross that species with another life form, even if it is closely related, and a lot of those optimizations are going to be disabled. But that isn't the end of the story.

Sometimes one species has a program (gene) that another lacks. What if we could lift that gene out and insert it into the other species. Cross breeding can do this. We can move a gene for nematode tolerance out of a wild species and into the domestic tomato. Now we have almost all of our original tomato programs (genes) complete, but we added a new gene that codes for disease tolerance.

So to partially answer your question, increasing diversity for the sake of increasing diversity usually just breaks a lot of genetic programs. Targeted gene transfer from one species to another can add new capabilities and enhance another species.

Tomatoes - meaning the domesticated species - have very little genetic diversity. Crossing them with a wild species has the potential to improve production, disease tolerance, regional adaptation, and many other traits.

The real question is whether or not it tastes good.:yes:

The poster asked about species, and that is what I assumed they meant. Particularly because they asked about which "wild species" might be best to use.

I do not think the question was about incidence of mutation.

[QUOTE=dmforcier;598607]Oh back off. That was shorthand for "variety, a subset of species".

So, do you believe that the poster is asking which variety has the highest incidence of mutation?


If it's not that, then what does the question mean?[/QUOTE]

[QUOTE=dmforcier;598607]Oh back off. That was shorthand for "variety, a subset of species".

So, do you believe that the poster is asking which variety has the highest incidence of mutation?

If it's not that, then what does the question mean?[/QUOTE]

Here was the original question

(Would crossing wild species whit each other increase genetic diversity and would there be benefits? Has there been such attempts?)

As the thread got longer other info as to genetic diversity was introduced in addition to crossing with wild species, not specified, and I for one,have no problems with that at all.

So no,the original question was not asking about the incidence of mutation,as I just said, the thread got off track,and why not since using germplasm from wild species is not the only way to be associated with genetic diversity.

My major growing field formanyyears was 250 ft long and 90 ft wide,rows 5 ft apart, and I'd go down the rows recording first blossom,first fruitset,indet or det,leaf form,first color on fruits,first ripe fruits, for each variety in my notebook.

But I never looked at the so called small details of a given variety.

One day I was at a website where Keith Mueller, I knew him from elsewhere, and this subject of diversity came up and he started discussing different internode lenghths, subtle changes in leaf form,time of ripening and more. I looked and he was right.

And well I remember what he said to me...something like those changes are there to see for those who have eyes.

Fusion here knows Keith well,so do I, he knows LOTS about tomato genetics and has also bred some very popular varieties.He got his MS degree with Dr.Randy Gardner at NCSU,one of the best breeders ever.

Here is Keith's website: I didn't take the time to see if he has any new updates.

[url]http://www.kdcomm.net/~tomato/[/url]

You can spend hours there,as many of us have,checking out all that he shares with others.

Carolyn

This thread has had some great answers -- but it might be worth mentioning one of the techniques used by Fred Pritchard that relates to harvesting benefits of genetic diversity -- if you're interested in century old work.

He was the person at the USDA who in 1918 developed the tomato Marvel from Merveille des Marches and crossed it with Livingstone's Globe to create the famous Marglobe -- which was very important in the 1930's because of greatly improved disease tolerance as well as high quality production for commercial and home uses -- and which is ancestor to many modern varieties.

(Pritchard also developed many other valuable varieties of tomato.)

He compared parent-candidate varieties for intravarietal variation with respect to the property he wanted to introduce or intensify, then worked by selection with a candidate variety that had high intravarietal variation to create a new variety with the target trait more prominently and consistently present. Often, he then crossed that new variety with other varieties that had complementary traits, stabilized the cross and released the new market variety.

I think that has practical application for the many home gardeners who attempt to develop an improved version of some variety by selection -- for earliness drought tolerance, etc . That is, before investing -- and possibly wasting -- many generations selecting, it might be wise to spend a season growing a large number of the variety they want to improve, determine whether it has a lot of intravarietal variation with respect to the target property and if not, use another variety, or use crossing techniques instead of or prior to using selection to achieve an improved variety.

Below is one place Pritchard discusses some of his work. Note that his work was utilitarian rather than theoretical or research oriented -- his goal being to produce tomatoes with desired traits as fast as possible and get them out to growers to grow or to further develop.
--------------------------

[url]https://ia801703.us.archive.org/11/items/developmentofwil1015prit/developmentofwil1015prit.pdf[/url]


BULLETIN 1015, U. S. DEPARTMENT OF AGRICULTURE. March 28, 1922

DEVELOPMENT OF WILT-RESISTANT TOMATOES.

By Fred J. Pritchard, Physiologist, Office of Cotton, Truck, and Forage Crop
Disease Investigations.

Fred Pritchard's name I know well and also Loran Blood's name as two of many who mainly in the 20's toearly 30's studied the basic traits of tomatoes since back then there were no DNA tests and more sophisticated methods of doing so.

Here's Marglobe from Tania

[url]http://tatianastomatobase.com/wiki/Marglobe[/url]

And here's a link to a great site from 1927,scroll down to tomatoes,which I have posted many times here and elsewhere on the difference between fibrous and tap root structures.

[url]http://soilandhealth.org/wp-content/uploads/01aglibrary/010137veg.roots/010137toc.html[/url]

There were many early breeders such as Blood and Livingston and Pritchard, and they had goals in mind when they crossed tomatoes, and made selections to get what they wanted or close to it.

Carolyn

Landrace tomatoes?

Very rare and strange for tomatoes as they mostly self pollinate, but there are examples. In this case, they might be closer to a varieties mix, but some crossing does happen every year.

It is widely accepted that wild relatives contain significantly more genetic diversity than the modern cultivated types of tomato (commercial hybrids and heirlooms). Charlie Rick estimated that wild relatives harbor 95%+ of the genetic diversity within Solanum. These wild relatives of tomato have contributed the vast majority of genes for resistance to various tomato pathogens, and will likely be a continued sources of genetic variation for tolerance to abiotic stress, and other characteristics . Can crosses to these wild relatives be used to improve cultivated tomato - yes they have. In fact, though it ★★★★es off some heirloom devotees, modern hybrids generally have more genetic diversity than heirlooms due to multiple introgressions of sequences from wild relatives for improved tolerance to multiple diseases.

Here is an article from Smithsonian
[URL="http://www.smithsonianmag.com/travel/why-wild-tiny-pimp-tomato-so-important-180955911/"]http://www.smithsonianmag.com/travel/why-wild-tiny-pimp-tomato-so-important-180955911/[/URL]

Modern Tomatoes "possess no more than 5 percent of the total genetic variation present within the wild species and primitive varieties. The domestic tomato’s progenitor has the other 95 or more percent. Modern tomatoes may taste good and offer eye appeal, but they lack many genes that allow them to fight disease and survive drought."

Does anyone grow wild tomatoes?

[QUOTE=Dark Rumor;600840]Here is an article from Smithsonian
[URL]http://www.smithsonianmag.com/travel/why-wild-tiny-pimp-tomato-so-important-180955911/[/URL]

Modern Tomatoes "possess no more than 5 percent of the total genetic variation present within the wild species and primitive varieties. The domestic tomato’s progenitor has the other 95 or more percent. Modern tomatoes may taste good and offer eye appeal, but they lack many genes that allow them to fight disease and survive drought."

Does anyone grow wild tomatoes?[/QUOTE]


Wild cherry is very close a real die hard of a plant.

Worth

[QUOTE=Dark Rumor;600840]Does anyone grow wild tomatoes?[/QUOTE]

I grow 5 species of wild tomatoes. So far, I have managed to cross one wild species with domestic tomatoes.

Next growing season, I may find some inter-species hybrids among the wild species. I'll be watching closely for them.

Fruits of an interspecies hybrid between domestic tomato and wild tomato.
[IMG]http://garden.lofthouse.com/images/tomato/solanum-habrochaites-x-domestic-fruit.jpg[/IMG]

Flowers of an interspecies hybrid between domestic tomato and wild tomato.
[IMG]http://garden.lofthouse.com/images/tomato/promiscuous-domestic-X-wild-large-petals-dominant_640.jpg[/IMG]

Wild maters
 

[QUOTE=joseph;600876]I grow 5 species of wild tomatoes. So far, I have managed to cross one wild species with domestic tomatoes.[/QUOTE]

Joseph could you expound on problems you've incurred trying to cross the wild ones with domestic. Do they just not take or they're not satisfactory for taste etc.? Found your threads interesting . Thanks

It is hard to catch a wild tomato.

Worth

[QUOTE=Worth1;600880]It is hard to catch a wild tomato.

Worth[/QUOTE]

:)):)):)):))

[QUOTE=Jimbotomateo;600879]Joseph could you expound on problems you've incurred trying to cross the wild ones with domestic. Do they just not take or they're not satisfactory for taste etc.?[/QUOTE]

S. habrochaites worked well for me as a pollen donor to domestic tomatoes. I currently have F1 fruits that are a few weeks from ripening, so perhaps I'll be able to post an update at that time. The fruits were the largest of any of the varieties of wild species. The fruits were hairy. Taste is variable with some being very sweet when fully ripe and soft.

S. pennellii, grew poorly for me, both in the greenhouse, and in the field. So I didn't get any crosses made with it. A few seed-like things showed up in some of the attempted crosses, but they didn't germinate.

S. peruvianum, and S. corneliomulleri grew well for me, but none of the crosses I attempted to domestic tomatoes were successful. Neither were attempted crosses to S. pennellii. I attempted crosses to S. habrochaites. Still waiting on the fruits to ripen. I didn't emasculate the mothers so I'll have to grow them out and look for children with traits mid-way between those of the parent species.

S. pimpinellifolium grows fine for me, and has survived the frost tolerance testing two years in a row, but the flowers are so small that I haven't been interested in using it in my breeding projects. I'm very ham-fisted for dealing with such tiny flowers.

One ongoing source of difficulty was not having pollen available at the same time that mother flowers were available, at the same time that the farmer was available. I was not expecting the crosses using S. peruvianum and S. corneliomulleri to be successful, so no worries about those. Because the flowers were so attractive to pollinators, it was often a challenge to get pollen from the flowers before the bees had taken it away.

S. corneliomulleri did not produce very many fruits, but a few plants made a few fruits, so maybe next year the descendants of those may produce better. The fruits were very small.

S. peruvianum grew well, and produced lots of fruits and seeds. The fruits on some of the plants were sweet and fruity. So it seems like there are some good genes there that may eventually prove useful. I saved seeds from the sweetest-fruited, intending to plant them next year, and create a population of sweet tasting wild tomatoes by plain old selection.

I grew a patch of the wild species interplanted with each other. There were lots of pollinators present and visiting the flowers. So perhaps some interspecies hybrids were created. I'm intending to plant large numbers of them, and then screen for anything that looks like it might be an inter-species hybrid.

So overall, I'm thrilled that so many of the wild tomatoes did so well.

[IMG]http://garden.lofthouse.com/images/tomato/solanum-peruvianum-bee-3.jpg[/IMG]

Great read Joseph , thanks for elaboration! Don't understand it all but fascinating just the same. Maybe your work will lead to greater disease resistance and sustainment of organic and tasty food for immediate and long range practices. Any way it's fun!! Good to see your success and luck to you for next year where hopefully you'll keep us abreast of new creations! The wild ones that are isolated but together should prove interesting.

I have S. pimpinellifolium coming up wild here ever since I grew it one year. I have grown to like the flavor and I am always amazed at how they can take anything. I have cut them down with a string trimmer and they come back. Never get disease, don't need watering etc. Would it be easy to cross them with other tomatoes? If I did would the crosses then have the genes responsible for the vigor of S.pip?

[QUOTE=BigVanVader;600990]I have S. pimpinellifolium coming up wild here ever since I grew it one year. I have grown to like the flavor and I am always amazed at how they can take anything. I have cut them down with a string trimmer and they come back. Never get disease, don't need watering etc. Would it be easy to cross them with other tomatoes? If I did would the crosses then have the genes responsible for the vigor of S.pip?[/QUOTE]

S pimpinellifolium and domestic tomatoes are completely cross compatible. The offspring would have half of the genes responsible for the vigor of S.pimp. Then you'd get to select, or allow your environment to select for vigor.

[QUOTE=joseph;600997]S pimpinellifolium and domestic tomatoes are completely cross compatible. The offspring would have half of the genes responsible for the vigor of S.pimp. Then you'd get to select, or allow your environment to select for vigor.[/QUOTE]

Thanks Joseph, I really love following your threads. Thanks for the quick answer. I will have to try this on some of my favorite tomatoes. While I have you here may I ask what would you say is the minimum melon varieties I would need to grow to get enough genes for a good landrace? I love melons more than anything but they are nearly impossible to grow here w/o pesticides.

[QUOTE=BigVanVader;601001]what would you say is the minimum melon varieties I would need to grow to get enough genes for a good landrace? I love melons more than anything but they are nearly impossible to grow here w/o pesticides.[/QUOTE]

Depends on the genetic diversity of what you start out with. If you start with a landrace, chances are pretty good that there'd be enough genetic diversity in it that something might work for you. When planting a packet of landrace seeds, it's like each seed is a unique variety, so it's an easy way to trial lots of varieties at little cost.

I trialed about 80 commercial/heirloom varieties when starting my muskmelon landrace. Most of them didn't even produce fruits, though some of the non-fruiting plants contributed pollen.

These days, when I start new landrace projects, I feel really content if I have about 5 different varieties in the beginning.

I really like getting seeds from the local farmer's market from farmers that are growing organically. Even if they are using commercial seeds, at least they are choosing varieties that do well under local conditions. In my initial muskmelon planting, I included seeds from melons obtained from 5 different local growers.