Hi Susan,
I hope you receive a reply to end this nonsense, but the more usual procedure would be for goldpiano to post his photo in the IAS I.D. center, but I'm afraid this would prove embarassing for him.

I don't think the c.v. "Lime Zinger" is that widely known outside the U.S., but because of the color most would assume this is Xanthosoma mafaffa from a photo.

If anyone would like an actual Alocasia in a similar color, A. macro "Lutea" is inexpensive, readily available, fits the bill, and actually grows larger here in Dallas, unless you just want to insist on growing an 'Alocasia'that looks exactly like a known Xanthosoma.

It's stuff like this that keeps people too confused to learn anything.

Well,Whatever!

Keiko

Okay, if anyone REALLY wants to get to the bottom of this: they need to obtain leaf samples from the Alocasia and Xanthosoma in question. Then find a molecular biologist pal, preferably one used to working with plant DNA, and have him or her do PCR assays on the TrnL gene. There should be sufficient differences once the PCR products are sequenced to determine whether the plants are identical, or whether they are in fact different genera. I'm not doing it. I have enough on my plate.

Lisa

:-)))))Lisa, This is far too obvious & nutty for most of us on the Gulf Coast to consider going thru anything like that necessary. It's still in the upper 90s, incredibly humid, more fit for Aroids than humans here.

Keiko

Isn't there someone on this forum who is a DNA analyst; I thought I recalled someone saying that, but maybe I'm going loony, too, now. Oh, come on, Lisa, what's a DNA assay?

Susan

Keiko, I never said I wasn't crazy :-).

Susan, I am a DNA analyst, and David (?) is as well. PCR assays are a technique used to determine if a given sequence of DNA is present in a sample (in this case, the DNA extracted from a leaf). If the sequence(s) of DNA are present, when the reactions are all run, there should be a stripe at a known location when the final reaction is examined under a UV (blacklight) light. (I'm leaving as much of the technical detail out as possible here)

Then, because related plants often have similar stretches of DNA, the stripe is extracted, purified, and more reactions are done so that the exact order of the DNA sequence can be read on a special machine. The stretches of DNA (as in the genetic code) are then compared. If they are completely identical, chances are, it's the same plant. If they have differences in excess of the standard error rates in these reactions (the error rates are very small), then the plants are different varieties, species or genera.

Here's hoping that makes some kind of sense.

Dear Susan,
Everyone seems to want to make the difference between Alocasia and Xanthosoma more difficult than it really is.

etropical, bihai, and others have already accurately gone over the differences between the two genuses trying to get people to see the light.

The only reason for DNA analysis would be if you would like to prove that the plants in question belong to another species rather than the X. mafaffa complex.

I think Dr. Goncalves in Brasilia is the world's leading expert in Xanthosoma & due to publish a new paper settling a lot of arcane issues shortly.

Keiko

Thanks, Lisa,
That does make sense and I can understand how and why the technique works when looking for an exact match. BUT, when they don't match, are you able to interpret the results to tell how closely the two samples are related, like whether they belong to the same genus or species?

Keiko

Keiko, the brief answer to your question is yes. You take the genetic sequences and enter them into some nifty software, along with other known sequences to provide context (I'd use comparable published sequences from other aroids, and then the sequence from the same gene in something like Arabidopsis), and the software tells you how closely related your sequences of interest are. It won't *specifically* tell you if they are the same genus or species, but it will group the sequences in order of likelihood of being the same genus or species.

About all I know is that I have that kind of software on my computer at work (and use it a lot), and that it involves a lot of statistical analysis beyond my understanding.

Lisa

Lisa,
Thanks for the clear explanation of how this works. It would seem to me that the number of statistical calculations required would make this a pretty accurate tool for trying to associate an unknown with a particular genus or species. I guess there must be a high cost or time factor involved that has kept botanists from using this more often to resolve some of the longtime mysteries.

Keiko

Keiko, it's a combination of both--extraction of DNA is tedious. THEN comes the analysis, and that's pretty pricey, although faster. Plant scientists tend, therefore, to stick to "model" plants for most of the genetic analysis (e.g. Arabidopsis).

Lisa, please please please please please please please! Now is the time I wish I was a geneticist and not a para-legal!

Susan

When you get down to it, it's always about time or money.
btw, I'm sure we would all be interested in getting the .pdf long answer when you have the time :-)

Keiko

Hey Keiko
Thanks for the kind words....
I just hope that at least one person can realize how improbable this arguement is.
When you break it down its even simpler than all this....If it walks like a duck, and quacks like a duck....then its a duck!

The triangular nature of the xanthosoma zinger leaf is quite profound to the trained eye.

looking for a place for buying AROID and or AMORPHOPHALLUS at fair prices and quality??Any have a clue on the request?Richie in PA.Thank you!

Richie, Where are you located in PA?? What exact speices are you looking for :o) Dan