I totally Agree!!! A judge should never screen a plant just because one think it is not what it seems to that person. The judges should judge what they see and let the taxonomist do their job and that is what the AOS rule on this.
Ramon
Ramon
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I totally Agree!!! A judge should never screen a plant just because one think it is not what it seems to that person. The judges should judge what they see and let the taxonomist do their job and that is what the AOS rule on this.
Ramon
Ramon
Leo Schordje
wilted blossom
Robert, that is one beautiful schillerianum.
Pete & Ernie, I agree with you guys. As to segregating polyploids for judging; not possible. Robert Q is likely the only one here, or one of a very, very few, that sits down in front of a research grade microscope and counts chromosomes. No way AOS judges could separate various ploydy counts from each other at a judging session. Virtually 99% of the growers, who make the claim that this plant or that plant is a polyploid are actually guessing. They simply do not have the chromosome count necessary to be certain. Now often a grower can make a good guess, but until one actually does the count, it is not correct to state that a plant is a particular ploidy number. Better statement would be to say, this plant is likely a 4N, rather than it IS 4N. I know, nitpicking, but it is the practical reason that it is unreasonable to expect AOS judges to separate polyploids from the diploids.
Pete & Ernie, I agree with you guys. As to segregating polyploids for judging; not possible. Robert Q is likely the only one here, or one of a very, very few, that sits down in front of a research grade microscope and counts chromosomes. No way AOS judges could separate various ploydy counts from each other at a judging session. Virtually 99% of the growers, who make the claim that this plant or that plant is a polyploid are actually guessing. They simply do not have the chromosome count necessary to be certain. Now often a grower can make a good guess, but until one actually does the count, it is not correct to state that a plant is a particular ploidy number. Better statement would be to say, this plant is likely a 4N, rather than it IS 4N. I know, nitpicking, but it is the practical reason that it is unreasonable to expect AOS judges to separate polyploids from the diploids.
E
Ernie
Guest
Leo,
As a fun aside, Bill Rogerson actually approached me about screening his Cattleya seedlings for ploidy. He said the person that used to do his lab work would screen them based on stomata diameter. Within a given population, he could predict with near 100% accuracy which would be polyploid (not necessarily 3N, 4N, etc). That guy retired, and Bill wants me to trian myself to do this for him so i can take his money. I think I could do it, and I have the equipment. Unfortunately, I don't have time. With this method, you'd need a 2N control or large population of mixed to compare against.
-Ernie
As a fun aside, Bill Rogerson actually approached me about screening his Cattleya seedlings for ploidy. He said the person that used to do his lab work would screen them based on stomata diameter. Within a given population, he could predict with near 100% accuracy which would be polyploid (not necessarily 3N, 4N, etc). That guy retired, and Bill wants me to trian myself to do this for him so i can take his money. I think I could do it, and I have the equipment. Unfortunately, I don't have time. With this method, you'd need a 2N control or large population of mixed to compare against.
-Ernie
Leo Schordje
wilted blossom
I know HP Norton also uses the guard cell measurements to identify the polyploids. If you have a grex specific reference set of measurements you can separate 2N from 3N from 4N. The measurements jump nicely with each level of ploidy. BUT you can't be certain about aneuploids, they fall inbetween. Guard cell measurements are definitely a good relatively inexpensive way to guess at ploidy number. At least with guard cell measurements it becomes an informed guess as to ploidy. You still need a decent quality disecting scope with the measurement scale built into one of the ocular lenses. They are cheaper than what you would need for chromosome counts, but still are not very cheap.
Roth
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Guard cells is of no meaning, unfortunately... I tried that and compared to hardcore chromosome counting, and it is not reliable. As for the 4n 2n etc... there are naturals 4n plants of many species around, so to mention it for judging would be quite useless...
Schilleriana, I have never seen a Philippine schilleriana like the Pink Princess, that's definitely a good 4n.
On the other side, I have seen schilleriana from Sabah, mine are going to bloom now. They are distinctive, as some have nearly no mottling of the leaves, branching spikes, and funnier, they make real stolons, like a very large flower spike with a plant at the tip... It could well be the 2n ancester of those ones. Sabah gets a lot of species that are similar to the Philippines, but usually of much better quality. Paph philippinense, haynaldianum, schilleriana, amabilis, etc...
E
Ernie
Guest
Fair enough, but tell that to Bill and the guy that used to flask for him. He was nearly 100% in IDing 2n's versus polyploids. I have not done it, but I've seen Bill's plants and do not doubt the results of his ploidy sorting. Maybe it's easier/more reliable for the Cattleya alliance (which Bill grows)? Maybe he trashed the ones he wasn't sure about.
-Ernie
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