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FranOnTheEdge
03-27-2012, 02:47 PM
1) Can DNA be used to determine the exact plant a burr came from?
2) Can DNA match the burr to say part of a stem from the same plant?
3) Is there a nice obscure plant that has burrs (about the size of your little fingernail - or no bigger than your thumb nail) the colour of wheat ready for harvest with prongs that are hard and sharp?
4) Please can this plant come from only Japan?
Or Madagascar?

Is there such a thing?

alleycat
03-27-2012, 03:42 PM
One of the species of cocklebur or burdock might work; I'm not sure which are native only to Japan.

GeorgeK
03-27-2012, 04:54 PM
http://en.wikipedia.org/wiki/Xanthium
Normally I denegrate the use of wikipedia, but there are sometimes some nice pictures and these little suckers are really hard to pull off your clothes and will even stick to hairy legs. They are in Eastern Asia as well as the US. Also if you are looking for something to match a location, having a non native plant that is in somebody's flowergarden would be a double whammy. I'm not sure how much DNA has been studied on a lot of the, "weeds".

auriel
03-27-2012, 06:08 PM
From what (little) I remember of one of my sophomore biology classes, plant DNA is way more complex than human DNA. Not upper-level-intelligence complex, just...weirder.

My educated guess to your first question would be yes, most likely. You get somebody specialized in plant DNA and give them plenty of time, you could get pretty close - but this depends on whether the DNA of said plant has already been studied. There's not really an international database of plant DNA. To the second - I don't think so.

*To be fair, I did get a degree in biology, but I made Bs in most of the science classes xD

RemusShepherd
03-27-2012, 06:24 PM
1) Can DNA be used to determine the exact plant a burr came from?
2) Can DNA match the burr to say part of a stem from the same plant?

My guess on both of these is 'no'. Many plants are clones of each other, reproducing via rhizome (runners underground). But that's just a guess, I'm not an expert.


3) Is there a nice obscure plant that has burrs (about the size of your little fingernail - or no bigger than your thumb nail) the colour of wheat ready for harvest with prongs that are hard and sharp?

Sandbur, also known as Grassbur. It looks exactly like long grass, but it hides wicked sharp burrs that can pierce through denim. I *am* an expert in this stuff; I've been trying to kill the evil bastards on my property for years. Unfortunately for your story it is not exclusively Japanese, although there is a sub-species that is limited to Hawaii.

Friendly Frog
03-27-2012, 10:30 PM
1) Can DNA be used to determine the exact plant a burr came from?
2) Can DNA match the burr to say part of a stem from the same plant?
I suspect a lot fewer DNA studies or genome decoding has been done for plants as opposed to animals. Yet I reckon (as a non-expert) that DNA can be extracted from seeds or burrs to determine their identity. I am fairly possitive DNA-barcoding is also done for plants. But I think that using DNA tests is a very rarely-used method on identifying plant parts because of the costs and lack of genetic material on file. In that aspect I think identifying a burr from plant photo databases would be a more common way of identification.

I suspect DNA can be used to match the burr to an individual plant if you have a workable DNA sample of both. But as RemusShepherd has already pointed out, many plants are clones so if you may have to look at the reproduction method of the plant for your plan to work.

backslashbaby
03-27-2012, 11:04 PM
"2) Can DNA match the burr to say part of a stem from the same plant?"

I'm thinking no to this part. Unless the plant has a mutation occurring in one part (which happens often enough), the DNA would be carried in too many parts. I think getting a bur from a sported (mutated) stem is a bit too much of a coincidence, too :( Check it out, though, when you decide on your species. Some plants are very mutate-y :)

veinglory
03-27-2012, 11:15 PM
1) Can DNA be used to determine the exact plant a burr came from?

Yes, assuming each plant in the area is from a unique seed.

2) Can DNA match the burr to say part of a stem from the same plant?

No.

blacbird
03-28-2012, 05:30 AM
My guess on both of these is 'no'. Many plants are clones of each other, reproducing via rhizome (runners underground). But that's just a guess, I'm not an expert.

I know of one murder case in which an unburned fire log was matched by DNA to a specific tree, and (I forget the exact details) that proved that the person who brought the log had been at the site of the murder, which he had previously denied. So it can be done, but I'd venture has rarely been.

caw

hlynn117
03-28-2012, 05:43 AM
1) Can DNA be used to determine the exact plant a burr came from?

I don't know how many genomic studies have been done with plants involving burrs...they don't make particularly good model organisms. The most studied genomes are those of model organisms because scientists use that information to make science. Most likely, you would be looking to amplify a specific region of DNA unique to that plant. Sequencing the entire genome is just too expensive. You would PCR a unique region. It's easy and way cheaper.


2) Can DNA match the burr to say part of a stem from the same plant?

Not a botanist, but I would say nope.

FranOnTheEdge
04-07-2012, 10:45 PM
It's so difficult isn't it?

I've already tried searching for burrs everywhere, I just haven't gotten any useful - and understandable - information.

I was hopeful of this, because of a forensics program on TV some time ago - they managed to prove a case because the seeds from a particular tree had been found in the purp's truck - they matched the seed pod's DNA to the tree's DNA and I think they said that DNA was definitely okay because plant DNA was where the science of DNA technology had first begun, so there were vast databases of plant DNA and a vast number of experts in this field...

Which is why I was hopeful about this.

The answers to this thread seem to be that some people say yes, and some say no... so I still don't know.

Shame. Now I'm not sure what to do about it.

Does anyone know who, or where, I might be able to ask to get any more information?

jaksen
04-07-2012, 10:54 PM
Go on a forensics forum.

I used to belong to a forum that gave advice to writers from scientists, doctors and other medical experts. They helped me out a lot. But, the PC crashed and I lost the forum address. (This was in the 1990's.) I used to get updates, too, in the form of email. Like: New Topic: Dead bodies which are burned.

Scout around and find a forensics forum if you are determined to get this correct. Not all forensic scientists are experts in DNA - many have their own specialites - but they will either be able to answer your question or point you to those who can answer it.

FranOnTheEdge
04-09-2012, 07:49 PM
Yes, that's a very good idea, I will look into that, thanks.

shaldna
04-09-2012, 08:03 PM
1) Can DNA be used to determine the exact plant a burr came from?

Plants don't have DNA in the sense that people do, so most likely the answer is no. Primarily this is because it's so much more complex, plus, taken into consideration the very nature of plants and the way we intervere with them, plant DNA is complicated and, to be honest, very under studied and not as well understood as human and animal dna.

However, it's very easy to determine species of plant, and, if the plant has been selectively bred or genetically enhanced then it's possible to trace it back to source.



2) Can DNA match the burr to say part of a stem from the same plant?

See above re. DNA in plants.

But also, you might not be able to get it down to the exact stem - unless there was tearing etc, but you could make a reasonable guess at age, and look at the fertilizer residue etc that would help determine the rough date, and from that determine roughly where on the plant the bur might have come from.