Lycopersicon peruvianum

[Raymondo]

I'm growing a plant of this at the moment and wondered about its reproductive habits. The style extends a number of milimetres past the end of the anther cone. I wonder then whether this species is an inbreeder or not. The stigma seems a long way from the anthers, so much so that I wouldn't be surprised if L. peruvianum was an outbreeder, perhaps even self-infertile. Certainly none of the flowers that have died have any fruit.
Does anyone have any experience with this?

[Tom Wagner]

Lycopersicon peruvianum has a gametophytic self-incompatibility

So the deal is.....a single plant of a species that is self-imcompatible is more than likely not to be a good selfer, thus no fruit set. Sometimes even one more plant nearby is not enough because it too, may have the same S alleles that aborts the pollen growth down the style. One may have to have several plants in order to have reciprocal mating sucess. Thanks goodness our cultivated clones of tomatoes don't have this problem. Not to say I have not done this because I have with some complicated backcrosses of cultivated/peruvianum lines. I welcome the SI factor in potatoes because it allows me to produce hybrid seed between clones without having to physically make the crosses.

Therefore peruvianum is an outcrosser and your single plant will likely never to have a fruit set.

For those who want a more technical viewpoint I have a composite explanation here...

Self-incompatibility (SI) is a general name for several genetic mechanisms in angiosperms, which prevent self-fertilization and thus encourage outcrossing. In plants with SI, when a pollen grain produced in a plant reaches a stigma of the same plant or another plant with a similar genotype, the process of pollen germination, pollen tube growth, ovule fertilization, and embryo development is halted at one of its stages, and consequently no seeds are produced. SI is one of the most important means to prevent selfing and promote the generation of new genotypes in plants, and it is considered as one of the causes for the spread and success of the angiosperms on the earth.
This is the more common type of SI, existing in the families: Solanaceae
Consequently, this mechanism arose approximately 90 million years ago, and is the inferred ancestral state for approximately 50% of all plants.

As the pollen starts to grow down the pollen tube there is a degradation of the ribosomal RNA (rRNA) inside the pollen tube, in the case of identical male and female S alleles, and consequently pollen tube elongation is arrested, and the pollen grain dies.

Tom Wagner

[Tom Wagner]

The degree to which stigmas are exerted above the stamen in flowers is a key determinant of cross-pollination (and hence allogamy) in many plant species. Most species in the genus Lycopersicon are obligate or facultative outcrossers ( Capable of occurring or not occurring) and bear flowers with highly exerted stigmas. Case in point --peruvianum. In contrast, the cultivated tomato (Lycopersicon esculentum) bears flowers with flush or inserted stigmas promoting self-fertilization.

Thought this might help explain a few things.....

Tom Wagner


BTW, some of my favorite clones of potato are exerted stigma types. I can usually be assured that they are mostly SI types and help my hand crossing and the potato flowers with shorter styles are self-fertilizing types for the most part. It seems that those long styles on the tomatoes and tomatoes allow for the SI pollen to die sooner. Take a look at flowers of Cascade, Agria, or Provento if you want to see the SI type potato flower structures.

[Raymondo]

Thanks Tom. I have three other Lycopersicon species in the same bed and our little Blue-banded Bee absolutely loves Lycopersicon flowers. I have since found out that L. peruvianum doesn't readily cross with those I've got but there is a chance. If I get fruit, I will assume one of these others was the pollen parent.

[Tom Wagner]

L. peruvianum is crossed to L. chilense fairly easily but not to our cultivated types..

[Raymondo]

The others I have are Lycopersicon esculentum, of course, L. humboldtii and L. pimpinellifolium. These all cross easily with each other so not with L. peruvianum. I have another unknown species but it's most likely a currant tomato.

[mtbigfish]

Originally Posted by Tom Wagner

L. peruvianum is crossed to L. chilense fairly easily but not to our cultivated types..

Tom
I know you started at about 10 with breeding/finding unique tomatoes - are you all self learned or do you also have formal education ie plant genetics/breeding etc
Thanks
Dennis

Ps when is your arm going to get twisted enough to send Carolyn some "clear epidermal" cherries you have hidden around? to grow out ??

[carolyn137]

Originally Posted by mtbigfish

Tom
I know you started at about 10 with breeding/finding unique tomatoes - are you all self learned or do you also have formal education ie plant genetics/breeding etc
Thanks
Dennis

Ps when is your arm going to get twisted enough to send Carolyn some "clear epidermal" cherries you have hidden around? to grow out ??

Dennis, I trialed 22 varieties for Tom back in the 90's and one of them was Verde Claro, a clear epidermis cherry sized but not shaped variety. Tom asked me not to share seeds, except with Craig leHoullier who was also supposed to be trialing them for Tom.

I have kept my word but then saw that Tom had sent what he called his improved Verde Claro to someone here at Tville, and I have no idea who else he might have sent it to as well.

Perhaps you didn't see the thread here about Jeff Casey and his clear epidermis cherry that was a spontaneous mutation from the variety Green Doctors, which was a spontaneous mutation from the variety Dr. Carolyn.

One other person, an SSE member who reads here but seldom posts, that's Neil Lockhart, also had the same thing happen this year, that is the appearance of a clear skinned Green Doctors which has been named Green Doctors Frosted. In both cases the GD seeds were original seeds from Amy Goldman in whose garden Green Doctors appeared.

Jeff and Neil at my request have sent me a limited number of seeds for Green Doctors Frosted which I plan to offer when I get my annual seed offer up here at Tville, and I'm late with that this year for all sorts of reasons.

Jeff is offering Green Doctors Frosted at his website;

http://members.shaw.ca/jwlcasey/Case...toes/Home.html

And Neil is listing it in the 2010 SSE Yearbook.

So Tom doesn't have to send me any clear epidermis cherries b'c I still have seeds for Verde Claro which I never shared except for Craig, and now I have seeds for Green Doctors Frosted which I'll be growing out this summer.

[goodwin]

It is odd that particular mutation has shown up in several gardens including mine.
Anyway, knowing it is virtually impossible to cross esculentum to L. peruvianum,
I was surprised to come across seeds for a peruvianum cross. Who knows if it is, but is definitely a wild cross. Take a look at the plant habit and foliage next to the smaller and lighter Nepal. They were planted at the same time.

[carolyn137]

Originally Posted by goodwin

It is odd that particular mutation has shown up in several gardens including mine.
Anyway, knowing it is virtually impossible to cross esculentum to L. peruvianum,
I was surprised to come across seeds for a peruvianum cross. Who knows if it is, but is definitely a wild cross. Take a look at the plant habit and foliage next to the smaller and lighter Nepal. They were planted at the same time.

When you speak of "that particular mutation" are you referring to your Green Doctors also mutating to a clear epidermis? And if so were your seeds also seeds that originated with Amy directly?

[Tom Wagner]

"Mountain big fish" or Dennis wrote:

Tom
I know you started at about 10 with breeding/finding unique tomatoes - are you all self learned or do you also have formal education ie plant genetics/breeding etc
Thanks
Dennis

I'm in my 6th decade of plant breeding and I began before I was 10 that is for sure. My training was kinda family oriented, but being quite hard of hearing I focused on doing what I thought the cows, chickens, corn, horses, cats, bees, and whatever the blazes other plants and animals were performing. Why I was consumed with making Leghorns more Bantam like is beyond me, and why was I making Bantam corn more like Stowell's Evergreen?

Seems like I always did three things at once like getting three full majors at the University of Kansas...Botany, Geography, and Anthropology. I was taking graduate courses in Cytogenetics and about to finish a major in Zoology before I graduated. Was about to work on a Ph.D with Bob O-Keefe at the Univ. of Nebraska (potatoes) but took a time off period working with Frito-Lay buying, storing, and testing FL potato varieties in the field, etc. A final attempt to go back for more schooling was aborted at Univ of Wisconsin, Madison due to a J.S.Niederhauser push for more foreign students.

Performing some contract work as a plant breeder in potatoes and tomatoes over the years and issuing a seed catalog, all interspersed with being a private breeding researcher....all pretty much dove tails on picking up skills as I went.
My training is more by torment than by anything formal.

Tom Wagner

[goodwin]

hi Carolyn -
Regarding Green Doctors, what I planted was from the folks at Sandhill. Do you know the source of that seed?

[carolyn137]

Originally Posted by goodwin

hi Carolyn -
Regarding Green Doctors, what I planted was from the folks at Sandhill. Do you know the source of that seed?

Probably Amy sent it to Glenn, I know I didn't. So what you have are Glenn's saved seeds from the plants he grew from Amy's seed.

And you might want to consider calling it Green Doctors Frosted as Neil and Jeff are, and me as well.

How did you realize that it was a clear epidermis mutation? I ask b'c I don't think there are any other varieties out there available to the public, just those that Tom bred, and perhaps the person here at Tville to whom he sent the Verde Claro Improved.

Clear epidermis green when ripes certainly are quite different from the normal yellow epidermis ones as regards color.

[goodwin]

Yes, Carolyn, that sounds logical. Here's the thread I posted to last fall with photos of the fruit. (Green Doctors skin colour)
http://www.tomatoville.com/showthread.php?t=12272

I think I'll wait until I've grown it out this summer before determining it is a stable mutation.

[carolyn137]

Originally Posted by goodwin

Yes, Carolyn, that sounds logical. Here's the thread I posted to last fall with photos of the fruit. (Green Doctors skin colour)
http://www.tomatoville.com/showthread.php?t=12272

I think I'll wait until I've grown it out this summer before determining it is a stable mutation.

Lee thanks for the link but when I got to the last post you said that since you could see an amber blush that you didn't think that you had a clear epidermis mutation and said you were going to grow it out again.


have you changed your mind about that and still think you might have an epidermis mutation after saying the fruits had an amber blush?

If it's a clear epidermis there will be no blush at all, trust me on that.