Dive in....

The talk here can get pretty scientific, so if you start to feel lost reading some of these posts, don't worry: you won't be alone! The intricacies of orchid breeding and cloning make for fascinating discussions, so if you're curious, all you have to do is ask....

Sue, the moderator of this forum, has a website here. Sue started a board devoted exclusively to orchid breeding, so between that site and this forum, I hope we can develop some good participation.

So let's begin.

I have these questions: How is tetraploidy expressed in an orchid's phenotype? In other words, is there some way to tell, just by looking at a plant, that it's 4N and not 2N? Do any differences make themselves apparent if a 4N and a 2N of the same grex are placed side by side? And if so, what would those differences look like, typically?

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Louis J. Aszod

Well, Sue has officially agreed to moderate.

I think you will like what you'll be seeing here.

Sue, thank you!

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Louis J. Aszod

Hi Louis-

There was an excellent article in last years Orchid Digest's special issue on Cattleyas that showed pictures of both normal flowers and 4n flowers side by side. The difference was obvious. The 4n flowers were much larger and fuller, with heavier substance. I don't think, however, unless you were a huge expert on a particular grex, that you could tell without the side by side comparrison; you would probably just think the flower was just very large and full.

From Woodstream's website...

Both tetraploid (4N) plants and triploid (3N) plants often exhibit improvements in flower size, color, substance, and sometimes, growth rate, when compared to similar 2N plants. On the other hand, 3N and 4N plants often grow larger than 2N plants and may produce fewer flowers. This said, many of the most spectacular Phragmipedium show plants seen today come from 3N and 4N breeding.

Interesting subject...and the increasing prevelance of 3 and 4n parents and offspring poses some questions for the judging community...how does ploidy figure into the standards by which one judges a flower?

What you said, catfan, has me thinking about
the reproductive aspect of flowers.
The judge evaluates the aesthetic value of a flower,
but not the reproductive.
it seems counterintuitive that the main reason for a flower is not
weighed in the evaluation of a flower's "flowerness."
I especially find it odd that many 3n's are sterile,
and are flowerly in appearance only,
and not function.
it doesn't seem fair that awards go to a flower incapable of passing on those
valued traits.
Correct me if anyone knows for sure,
but I think in AKC dog shows for conformation & stuff,
the dogs may not be altered,
so the winners are able to pass on their genetics.
I guess it's just too hard for a judge to know if a plant
has been neutered of not.

You are absolutely right about judging dogs (and cats). They must be "intact" in terms of reproductive ability. Although they do have separate shows for neutered animals that offer lesser awards.

As for 2N, 3N and 4N.... I'm clueless and prefer to remain that way, so I continue to buy what I like, no matter how many Ns.... (I'm not planning on doing any breeding either...)

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Diane

"NA BEAN DO'N CHAT GUN LAMHAINN"

polyploid plants often have thicker and larger leaves than the regular diploid forms. intuitively that makes biological sense because if you figure that the extra chromosomes code for at least some structural protein, each individual polyploid cell stands to be larger than a diploid cell. don't know if that's been proven, but it's often given as a reason behind the overall larger plants.

sometimes people will say they may have "wrinkled" leaves, meaning longitudinal wrinkles along the leaf surface. many other things can cause this too.

bottom line as far as I'm concerned, it would be difficult to tell plants apart since there tends to be a great deal of natural variation in most crosses. maybe side by side, in a cross that was colchicine-treated, you might have an educated guess at which ones were successfully converted.

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Jason

I'm going to a judging center tomorrow for a monthly judging, and I will print out this thread and take it with me. I know that this subject has been brought up before, and we are supposed to discuss it. I'll let you know what they say...

catfan, definitely post back--I'm really interested to hear what they say.

Hybridizers have been doing this for quite a while now, but I'm really noticing it with Phrags over the past few years: crossing a tetraploid parent with a diploid one to deliberately produce a triploid mule. The idea is to prevent anyone who buys the offspring from using that cross as a stud plant. The same crosses are also made using both diploid or tetraploid parents, whose progeny are either sold at incredibly increased prices, or kept for the hybridizer's own use. This practice effectively "copyrights" the offspring for the short term, though, of course, it doesn't prevent anyone else from making the same cross themselves if they can get hold of two 2n or 4n parents.

Ennui, you've made a really good point, I think. But without cheaply available DNA testing, how are we to really tell for sure (and judge accordingly) whether a flower is "whole?" Plus, there's a pragmatic issue as well in that AOS judging, even as it stands now, takes boatloads of time. Can we expect judges at shows, already under serious time constraints, to take even more of it doing a DNA test on possible contenders for a quality award?

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Louis J. Aszod

LJA there is a quick fix for that problem. Now this would provide that the DNA testing prices are resonable. All they have to do is judge normaly, and if the plant recieves the award then test it. They are given the award pending the test results. If things come back hunkydory then the award stands if not then its revoked. They do the same thing in Nascar for the Datona 500. The winning car is given the trophey and all the celbrating is done, but the car is dismantled and tested to make sure everything is par and ok and not breaking any rules. If the car is found to be illegaly altered then the win is revoked and the second place winner wins. The car is also inpounded for the season so it can be displayed in Datona's museam(sp) for the season. IN fact I think they test every winner of ever race, but the only one that keeps the car for the year is the Datona 500.

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Josh

So many orchids and so little time!!

I did not get a good answer at the judging center this weekend in re flowers, ploidy, and judging. Just didn't have time to pursue it. I did have my interview for being accepted as a student judge, (I was accepted,)...and I got my first ever AOS award...86 point CCM for my Epi. russeauae 'Jerry Foster' ...

http://www.orchidspecies.com/epirusseauae.htm

It had never been awarded before...I'll try to get some more answers on the ploidy topic soon-

c.