Rare Peas - Identification

[heirloomgal]

I am growing a new pea variety this year called 'Argenteum'. It is said to have silvery leaves, and so far it seems to, but there are other regular green pea leaved plants that have sprouted as well. Does anybody know if this variety has this kind of variation in leaf colour? I'm tempted to pull the unusual plants out, but wouldn't want to waste the few plants I do have if there is some natural differences in colour expression. I really know very little about this variety and would like to keep it true to type if possible. This planter contains all the plants I will have to save seed from.

Here is the planter - (I can't figure out how to rotate the image - sorry)

 

[PhilaGardener]

The simplest explanation may be a seed mix-up by the grower or vendor. Easily solved by removing the green seedlings.

The Arg trait has an interesting history: https://www.ars.usda.gov/pacific-we...ocs/ga-marx-pea-genetic-stock-collection/arg/

Arg is a dominant mutation, meaning that the silvery foliage shows up whether the plant has one or two copies of the Arg gene version. If there was outcrossing at some point (rare in peas but it does happen), the first generation would all have silvery foliage, but in the second generation (and beyond) standard green plants would appear (in a ratio roughly 3 silver to 1 green, sort of like we see in your flat.

In this case, if you just keep the silvery plants, the green trait is still in 2/3rds of them. So that population will continue to give both silver and green offspring.

To get back to 100% Arg, you would have to separate individual silvery plants and then save seed from each. 1/3 of those will give offspring that are all silvery (you have to grow seeds from each plant to tell). Save only the seed from those individuals and you will have eliminated the non-silvery genes.

 

[Zeedman]

One way to rotate the photo (other than to rotate it in your file) is to copy & paste to your desktop, then rotate it there. That leaves your original photo unaltered.

I've never grown Argenteum, but it looks interesting. According to SSE, it can be used as either a shelling or soup pea. Provided it is grown in the absence of pollinators, you should be able to eliminate the impurity in two generations using @PhilaGardener 's advice.

Presumably the seed origin was another seed saver... if from a seed company, it would reflect very poorly on their isolation & quality control methods. If you are interested in trying another source, SSE itself (as Heritage Farm) is offering seed for Argenteum this year.

 

[heirloomgal]

Thank you @PhilaGardener @Zeedman very much, I appreciate the expert feedback!

My first thought was that it was a cross too, but the friend I got my seeds from is an expert seed saver. She really knows her stuff. And peas (I thought) cross so seldom too, but I guess it's always a possibility because of the nature of open-pollinated vegetables. But I found something online that could also possibly explain what is going on..... what do you think?

Argenteum (Arg) mutant of Pisum: Genetic control and breeding behavior​

G. A. Marx
Journal of Heredity, Volume 73, Issue 6, November 1982, Pages 413–420, https://doi.org/10.1093/oxfordjournals.jhered.a109690
Published:

01 November 1982

The phenotype, however, is not completely stable. Instability is marked by variegation—irregular patches of green tissue—and by distorted segregation ratios. Distorted ratios result from a higher than expected number of green offspring, the excess being attributable to plants that mimic those produced by Mendelian segregation but originating in a non-Mendelian manner.
The marker, PI, aids in distinguishing such green plants, designated “arg”, from normal arg/arg segregants. Green “arg” plants also may descend directly from Arg/Arg plants. Arg/Arg plants that are valegated in the reproductive region produce more “arg” offspring than those that are varlegated In the vegetative region only, or those that are not variegated (visually) at all. Once the Arg phenotype is converted to “arg” the latter is in herited as monogenic recessive.

I don't find this technical language especially easy to penetrate, but I think one of the things this passage is saying, is that argenteum peas always produce a certain number of green plants...well, I think it's saying that...

The question to me now is if I keep those green plants, can they produce silver pea leaves in future generations because they still carry the genes...

 

[Zeedman]

Well that is interesting. Peas can cross (I've had that happen) but that may not be what happened in this case. If the reference is correct, this really is one odd pea.

Green “arg” plants also may descend directly from Arg/Arg plants.

Which can explain how even properly saved seed - in the absence of crossing - could still produce green offspring. And apparently those green offspring result from changing a dominant Arg/Arg into a recessive? Maybe @seedcorn can explain how such non-Mendelian behavior can occur... and if we are likely to see such behavior in other plants.

Arg/Arg plants that are valegated in the reproductive region produce more “arg” offspring than those that are varlegated In the vegetative region only, or those that are not variegated (visually) at all.

So according to this, you would still segregate for seed saving as described by @PhilaGardener ... but if I read this correctly, it may remain unstable regardless. This seems to be a seed saver's nightmare.

 

[heirloomgal]

Hahahaha...that's hilarious @Zeedman. Yup, I may have found myself a difficult pea. We'll see how good it is in the kitchen. It's quite pretty though, in certain light it actually looks white. The only other selected mutant I've grown is a variegated pepper, Fish I think it's called, and it eventually produced a giant mule plant for me. That was the last time I grew it.

 

[Zeedman]

I've seen one plant which seems to display a similar behavior - Bishop's Weed. It is normally variegated, and is widely planted in this area (my Mother & DS both have it on the North side of their houses). But everywhere it grows, it eventually reverts to all-green foliage.

 

[flowerbug]

I've seen one plant which seems to display a similar behavior - Bishop's Weed. It is normally variegated, and is widely planted in this area (my Mother & DS both have it on the North side of their houses). But everywhere it grows, it eventually reverts to all-green foliage.

yes, i've seen this in some variegated plants too. since those with more chlorophyll are going to be at an advantage it has to be weeded out - which ruins the nice look of a planting.

 

[heirloomgal]

Uh oh, I think the scientists haven't quite figure this one out either. Found this, in the same article as above:

Phenotypic instability could not be satisfactorily explained by any of the mechanisms investigated, including nuclear/cytoplasm interaction and modifier gene action.

Well, I guess this one will just be for fun.

 

[Pulsegleaner]

I've seen one plant which seems to display a similar behavior - Bishop's Weed. It is normally variegated, and is widely planted in this area (my Mother & DS both have it on the North side of their houses). But everywhere it grows, it eventually reverts to all-green foliage.

I think around here something similar happens with morning glory. No matter what color flowers you start out with, if you let the stuff cross into itself (or it goes wild) it will eventually revert back to pink, blue or white, and eventually, to white only.

I also know that, if you find a variegated plant that roots itself well from cuttings, and you take a cutting that is ALL white (it can happen), if the cutting takes, something will turn on to make it produce green bits again so it can survive. Happened to me with my Spanish Thyme (Plectranthus)