TRANSCRIPT OF TOPIC
NOTE: Magda's editing is preceded by a series of three asterisks.
mplewinska (Magda from Miami)
Hi, all! I'm here to answer all your genetics questions. We start in five minutes.
KB Barrett (Kathy in N Calif.)
Hi Madga!
mplewinska (Magda from Miami)
Ellen, sure. Ask whatever.
bmtorchids (Barbara)
Hello Magda, I'm all ears.
mlp2
Hi Magda, been waiting for you.
121133ellen
Which parent will have a greater influence on the seedlings, the pollen or pod parent?
Next, if you cross Phrag besseae with caudatum will you shorten the time necessary to bloom?
mplewinska (Magda from Miami)
Well, the first thing I wanted to make sure everyone understood is how orchids inherit traits from their parents. It's probably easier to talk about hybrids, but it works the same way for species.
121133ellen
Is there a basic book on genetics that a layperson can understand?
mplewinska (Magda from Miami)
Pod or pollen parent.... The short answer is 'the pod parent', but you really need to know a little more.
Evlyn
Magda--please start on the kindergarden level.
mplewinska (Magda from Miami)
To continue with the pod/pollen parent story. There are two sets of inherited DNA in plants. One is the nuclear DNA - the sort we usually talk of when we discuss genes. This is contributed equally by each parent. The other kind is organelle DNA. This is found in the chloroplasts (where photosynthesis takes place) and the mitochondria (where respiration takes place). This is inherited only from the pod parent.
Clare in LA
Magda, why the pod parent? Why not 50/50?
bmtorchids (Barbara)
Madga, I always thought it's like human, some will inherit more from the pollen, some from the pod parent.
mplewinska (Magda from Miami)
Ellen. Rebecca Northen has a pretty good section on genetics in her Home Orchid Growing. And most modern botany books have pretty good sections. But you have to know some basic biology or you'll get lost in the lingo. The lingo is the hardest part to learn in any field.
bmtorchids (Barbara)
Yes Madga, I always read it and just went over my head.
LeslieV1 (From Parkland, Fla. (Leslie))
I'm glad I'm not the only one, Barbara.
bmtorchids (Barbara)
Leslie, I have Northen's book for years, only go back to it when I'm in trouble.
121133ellen
Madga, I was a biochem major many years ago and am familiar with certain terms, but because you can hybridize different species like Heinz variety, things change.
What seems to hold true for one species may not be true for another.
mplewinska (Magda from Miami)
Clare. Have I answered your pod/pollen question?
Barbara: Each individual inherits the same amount of ***nuclear DNA from each parent***.
This is called the genotype.
Some characteristics appear to be inherited from one or the other parent when the gene coming from that parent is dominant to the one coming from the other parent.
These visible effects are called the phenotype. For example, in most cases when you cross a white flower with a purple one, you'll get purple because the purple is dominant. But the white parent has contributed to the plant's genetic make-up.
You'll see this when you cross the offspring with itself and you'll get some white flowers.
bmtorchids (Barbara)
Madga, that is a very clear answer, Thanks.
121133ellen
Is he reasoning behind a besseae and caudatum cross to increase red coloration and decrease size.
KB Barrett (Kathy in N Calif.)
Madga, how much do Mitochondrial and Chloroplast DNA add to the phenotype? I never thought it was expressed.
mplewinska (Magda from Miami)
Ellen. The reasoning between the bessae and caudatum is to get the red color and put up with smaller size until the next generation.
121133ellen
Does it make any difference as to which is the pod parent?
KB Barrett (Kathy in N Calif.)
Until the next generation? So the larger size will come back? Is that a trait growers want? I know the red color is. Does the color fade over generations? Pretty tough crowd tonight, Magda!
121133ellen
Will the more vigorous seedlings in flask be the more vigorous plants.
mplewinska (Magda from Miami)
Kathy. I don't know that I can put a number to it, but: The chloroplast DNA codes for all the stuff that has to do with photosynthesis. Chroroplasts may also contain some pigments. The yellow color in some slippers comes from chloroplasts. That's why the right pod parent is important in those crosses.
bmtorchids (Barbara)
Then again, the red color if in favor right now, the next genertion may want pink or something.
mlp2 (mlp2 (marylou))
Ellen, in my experience the most vigorous plants in flask can be the first to die out of flask!!
LeslieV1 (From Parkland, Fla. (Leslie))
Why is it so hard to come up with a red Phal.?
KB Barrett (Kathy in N Calif.)
Usually we know nothing about the topics under discussion, I have just enough knowlege to be easliy confused (my natural state!)
mplewinska (Magda from Miami)
Kathy. Size is not inherited in a straightforward dominant/recessive way that (some) color is. Size is the result of a summation effect from a number of genes. So getting a large size means you keep crossing the largest offspring to each other (or to themselves) and the size should increase. You also have to be looking at the other characteristics at the same time, that's what make it more complicated.
121133ellen
I am a phrag nut and have just bought several Ratcliffe flasks of besseae and caudatum. I wonder how long till I see a bloom from these plants?
In otherwords, besseae will not bring down the size of a caudatum hybrid nor shorten the time till bloom?
mplewinska (Magda from Miami)
Red phal. It's difficult to get a red phal because phals just don't have that red pigment. The red in phals is either a dark pink or a bright brown on top of yellow. All the breeding in the world won't can't come up with
something that isn't there to begin with. That's why the people who wanted to get a blue rose made a transgenic one - they put a blue pigment from another plant (petunia, I think) into a rose.
121133ellen
What is the purpose of the 4N hybrids.
LeslieV1 (From Parkland, Fla. (Leslie))
That makes sense! Then why is everyone breeding for reds!
Evlyn
What does 4n mean?
bmtorchids (Barbara)
Leslie, you always want the hard to get.
mplewinska (Magda from Miami)
4N plants are just more vigorous than 2N (diploid ones). The trick you are probably thinking of is making a 6N plant from a 3N one. 3N plants grow fine but are usually sterile because one of the steps in reproduction involves pairing of chromosomes. Since 3n plants have an odd number of chromosomes,
the pairing is a problem. If you double the chromosomes to make an even number, everyone will have a partner to pair with and the plant will now be fertile.
bmtorchids (Barbara)
Ahhh, now I know.
mlp2 (mlp2 (marylou))
I'm still having some problems but have been working through them. On the red Phals - in the beginning there was a lot of infertility that growers have spent years working through and around so that now we have a few close to true red. The early ones were reddish purple, and then the reddish mahogany, etc. All beautiful but hardly a true red. But our pinks are really mostly lavenders!!
mplewinska (Magda from Miami)
4n means having 4 times the haploid amount of DNA. The normal amount of DNA in each cell is 2n or diploid, one chromosome from each parent. The normal amount in reprodustive cells (gametes) is n or haploid. Then when 2 gametes combine to make the new offspring, you get n+n=2n, a normal diploid
complement (amount).
runnerRick (Rick in Concord, CA. Diablo View OS, AOS)
Barbara, I just arrived from SF. Unfortunately, I've missed most of what I figured would be a most interesting discussion and don't just want to break in with a stupid question. But, I guess that I could, if prodded...
emddvm11 (Mike near Memphis)
Magda, if tetraploid plants are more vigorous, why are there not more around? Can you define your interpretation of vigorous?
mplewinska (Magda from Miami)
Rick. We have slowed down some, so please ask any questions. There are no stupid questions.
121133ellen
When they say a plant has been treated with cochicine, what is it?
What are the advantages of a 4N plant. Are they more vigorous?
bmtorchids (Barbara)
Can you tell if a plant is tetra or diploid? Can you tell by just looking at the flower?
mplewinska (Magda from Miami)
Vigorous: bigger, faster growing. Why aren't there more around? Beats me. If you cross a tetraploid with a diploid, you'll get a triploid which is sterile. So a tetraploid had to find another tetraploid to cross with to
make fertile offspring. It can cross to itself, of course, but that cuts down on genetic diversity. Maybe that's what catches up with them, in the end. Maybe there's another reason, but I don't know it.
ChuckMyr (Chuck in Austin, MN)
Barbara, one can tell 2N from 4N for sure only by microscopic examination of the chromosomes - hard to do without experience!
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
IMHO, the whole idea of genetics is to develop an understanding of what can come from a cross and try to understand what to cross to reach an intended effect - as you mention, the red Phal. - I do my crosses of my Onc. and try to imagine what the results will be without much understanding of what dominant traits any particular plant brings. Is there a reference of dominant traits for each species?
Magda, how does one treat a cross with colchicine? What is the process and when does it get done?
[NOTE: Colchicine is a very dangerous, poisonous chemical - to be used only by the professional and, then, with great care...mlg] ***[Ditto...mp]
[See Filename: colchicine1.4 re use of colchicine...Aaron Hicks.>
mplewinska (Magda from Miami)
Colchicine is how you get a tetraploid (4n) from a diploid (2n) or a hexaploid (6n) from a triploid (3n). What colchicine does is allows the DNA to duplicate but prevents the cell from dividing in two. So what you get is
the same number of cells with twice the DNA. You've doubled the amount of DNA per cell. Most cells you do this to die but the few that survive are the ones that will give rise to your new breeding stock.
LeslieV1 (From Parkland, Fla. (Leslie))
Magda, this may seem like a stupid question but, If I am not interested in breeding orchids, why would this information be pertinent to me? If I buy a compot of phal,s. is there something I should look for in the vigor, or the leaves?
121133ellen
Rick you asked the 64,000 question, where can you find the dominant traits for each species?
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Is colchicine used at the time of fertilization or is the pod soaked in it or is it in the flask?
ChuckMyr (Chuck in Austin, MN)
And the point that most cells die is important. Colchicine is as potent mutagen - very dangerous!
KB Barrett (Kathy in N Calif.)
Have we got an answer to the colchicine question? Is that how 4n's are arrived at to begin with?
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Kathy, Magda - aren't some 4n's realized in some natural crosses?? Or are they all induced?
121133ellen
Will treatment with colchine produce mutations?
mplewinska (Magda from Miami)
You can't tell whether a plant is 2n or 4n without doing a karyotype. This means a special lab preparation where you can see the dividing chromosomes and count them. With a microscope and special stains, of course. In the old days, treating a plant with colchicine was done by dripping a very dilute solution of colchicine onto a new eye. Now it's done to cells in tussue culture. And you want to count the chromosomes in those cells before you use the plant for breeding.
[Magda - question: Needs electron microscope? mlg]***[No, just a good light microscope and a lot of experience with technique to prepare the slides so that you can count the chromosomes reliably.]
ChuckMyr (Chuck in Austin, MN)
Turning a 2N plant into a 4N plant is a mutation.
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
So, colchicine is administered in the mother flask and then the protocorm is examined for ploidy?
121133ellen
I realize that, Chuck. I should have said will it produce undesirable traits?
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Where does one get some colchicine?
mplewinska (Magda from Miami)
Chuck. I don't consider turning a 2n plant into a 4n one a mutation. What people usually mean when they use the word mutation is that there is a change in the character of the genetic makeup of an individual. Changing the ploidy (as in diploid to tetraploid) is only changing the amount. Colochicine in itself does not cause mutations but it may cause genetic problems further down the line.
ChuckMyr (Chuck in Austin, MN)
Some chemical and biological supply companies carry it. As a private individual you might have a hard time getting it unless you or someone you know works at a lab or university.
121133ellen
Another question on hybridizing phrags. Many hybrids have besseae as one parent. Now they are crossing besseae back to the hybrid. If there is a double dose of besseae, will the plant resemble besseae or can the other parent be dominant?
KB Barrett (Kathy in N Calif.)
As far as phenotype and 4N plants, I've seen some of the 4N Cymbidiums that E.Young makes and boy they are larger and more spectacular. Same for their Paphs, just HUGE! So perhaps you can tell just by looking...???
***[You can't, see above - mp]
mplewinska (Magda from Miami)
Leslie, what was your question again? Why this is important for you to know?
Right, colchicine is given in the tissue culture mix and then you look at the chromosomes.
LeslieV1 (From Parkland, Fla. (Leslie))
Yes Magda. I'm not interested in breeding orchids. I am interested in buying compots of phals., etc. Will this information help me make a good puchase?
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
My surprise is that with all the hybridizing that is occurring, that someone isn't writing a book on dominant traits that appear to be carried forward by whatever particular species Seems that we are missing the boat on this one...[Such knowledge is hard to come by - mostly by experience or an older grower confiding in a protege...much treated as "trade secrets". With much reading, you can piece some together, piece by piece - the bane of the student judge!...mlg]
JCY8S (John in Arcadia, CA)
Rick - Are things like this being written in the AOS Lindleyana?
KB Barrett (Kathy in N Calif.)
Rick!!! Wake up!! That's the Bread and Butter of Hybridizing!!!! If I knew how to make a very expensive cross I'd be a fool to tell you!!! My knowlege of hybridization is all I have to sell as a commercial grower!
mplewinska (Magda from Miami)
Besseae crosses and dominance. Sometimes the besseae is dominant, sometimes the other parent. What you try to do is have stud plants that are homozygous for the characteristics you are breeding for, so you can predict what will happen in the offspring. To be homozygous means you got the same gene from each parent. So a homozygous white would have gotten a white gene from each parent, a homozygous purple would have a purple gene from each parent. However, a heterozygous purple (which would look exactly like the homozygous purple) would have gotten a purple gene from one parent and a white gene from the
other parent. Then when you bred with it, the heterozygous plant would transmit the white gene to half its progeny and the purple gene to the other half and you would have an unpredictable mixture of henotypes. This is what breeders try to avoid.
JCY8S (John in Arcadia, CA)
Yes, Kathy, but even the commercial peoiple frequently pull some lulus of crosses. I think that private growers can make crosses that the commercial people can't and can very possibly advance orchid knowledge by making these strage crosses. I mayself have maade crosses that a commercial person couldn't. I have gotten some very interesting things.
mplewinska (Magda from Miami)
Leslie. What you would have to know is who the parents of the cross are and what's recessive and dominant in them. That takes a fair amount of studying. Unfortunately, it's not all written down in one place. Most of it is scattered here and there.
121133ellen
Magda,where would you find some of that info?
mplewinska (Magda from Miami)
Go to a university (or better, a botanic gaarden) library and look through orchid and other botany books they have
.
LeslieV1 (From Parkland, Fla. (Leslie))
I bought a compot of Phal. Goldberry, and venosa. What do you think?
JCY8S (John in Arcadia, CA)
Leslie that sounds like a good cross. I have a bud coming on a first time cross of Phal. Fairport x venosa (my own cross). I hope that it is good.
mlp2 (mlp2 (marylou))
Came back after taking my puppies out. Wanted to say to remind people that not everything is completely dominant or recessive. We have a lot of blending of color, intermediate sizes etc. that are sort of in between. Magda possibly can explain this scientifically.
KB Barrett (Kathy in N Calif.)
Rick, that's why I always wonder what we're buying when a catalog states 'we're expecting plenty of blush reds from this cross' Like do they know?? Have they bloomed this one yet or are we buying blue sky? Leslie, that's where knowing a little about genetics comes into play for the hobbyist.
mplewinska (Magda from Miami)
Leslie, sorry, I don't know what to expect from that cross. What did the breeder tell you?
LeslieV1 (From Parkland, Fla. (Leslie))
I hope you have good luck with it, John. What does Fairfax look like?
Carmela...Just said it should be good. Who knows..
.
mplewinska (Magda from Miami)
Marylou. When you have blending of colors or other traits (like size), it's called co-dominance. ***It means that for that particular trait, genes from both parents are being expressed more or less equally, instead of one being completely dominant over the other...mp
Did they say venosa? It usually gives beautiful small flowers that have stripes, sometimes with a fading of the older flowers.
bmtorchids (Barbara)
A little knowledges is very dangerous, I'll never buy another plant that's not in bloom.
Evlyn
Maybe after the Santa Barbara show???
bmtorchids (Barbara)
You got it, Evlyn.
LeslieV1 (From Parkland, Fla. (Leslie))
Amen to that, Barbara!!!!!!
ChuckMyr (Chuck in Austin, MN)
Magda, isn't a trait like 'size' often polygenic as well??
JCY8S (John in Arcadia, CA)
Phal. Fairport is a large white with almost overlapping petals and a nice dark pink lip. It blooms for a long time and the spike branches constantly. With venosa I am hoping for a medium size with a pink lip and good shape AND maybe a light yellow(?)
LeslieV1 (From Parkland, Fla. (Leslie))
Thanks, Magda.
mplewinska (Magda from Miami)
More on co-dominance versus dominant/recessive. Usually with a dominant/recessive system, the recessive gene is null, that is does not do anything (like produce a pigment). The dominant gene is the one that does something. That's why when a plant has both a recessive and a dominant gene, you see only the effects of the recessive*** one. When two genes are co-dominant and both are expressed, you see the effects of both and you get the in-between characteristics.
[*I meant "dominant" here, as Leslie pointed out. See below - mp]
LeslieV1 (From Parkland, Fla. (Leslie))
Sounds beautiful, John!
Why wouldn't you see the effects of the dominant gene, Magda?
mplewinska (Magda from Miami)
Chuck. That's right. Size is really polygenic. I guess that was a bad example.
Leslie. Oops. I meant to write you only see the effects of the DOMINANT gene. Put me down for the world's worst typist.
LeslieV1 (From Parkland, Fla. (Leslie))
See, I'm paying attention!
ChuckMyr (Chuck in Austin, MN)
If I had to guess, I'd bet most orchid traits are polygenic. Makes for a real mess when trying to make predictions. Mendel was real lucky when he used pea plants. Most of his traits were controlled by single genes and their alternative forms.
bmtorchids (Barbara)
Madga, we can decipher anything.
LeslieV1 (From Parkland, Fla. (Leslie))
How would you find out which hybrid or species would be dominant or reccesive?
mplewinska (Magda from Miami)
Probably most traits are polygenic in any organism. Mendel was both lucky to have his traits be single-gene and smart enough to pick them that way.
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Ah Leslie, thank you for reinforcing my point. That appears to be the crux of the problem. If we only knew the relative strength of a trait (or gene)...
bmtorchids (Barbara)
Now every time I look at an orchid flower. I'm going to wonder if it is a Diploid or a Tetraploid. Shopping never gets any easier.
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Do we know what each gene does? Has science progressed that far yet?
mplewinska (Magda from Miami)
Leslie. The only way to find out which trait is dominant is to do the experiment - cross the plants. And you have to make sure you know that your parents are homozygous for the traits you are testing. Otherwise you won't be able to interpret the results. It's not always straightforward.
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
No wonder I'm attracted to this, its complicated...
mplewinska (Magda from Miami)
Rick, we know what some genes do and not what others do.
LeslieV1 (From Parkland, Fla. (Leslie))
So it sounds like hit and miss.
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
How do we know if the plants are homozygous or hetrozygous?
mplewinska (Magda from Miami)
Leslie. It is hit and miss. The good thing is that once you've figured it out for one characteristic, you can use that knowledge. The problem is that you have to figure it out for all the other traits one by one. Of course, you can always make educated guesses and sometimes, you'll get lucky!
KB Barrett (Kathy in N Calif.)
No, it sounds like alot of hard work! And work that takes alot of time, growing each cross to flowering stage takes years. Even Dr. Wang says 1 1/2 yrs from flask to flower for his phals. Many people say it takes longer.
LeslieV1 (From Parkland, Fla. (Leslie))
Good question, Rick.
Evlyn
Thanks, Magda, for taking the time to try and educate us. Really appreciate it.
mplewinska (Magda from Miami)
You determine whether a plant is homozygous or heterozygous by crossing it to itself. If it's homozygous, all the offspring will look like the parent (for the trait you are looking at). If the plant is heterozygous, crossing
it to itself will produce a mixture of offspring manifesting the dominant and recessive trait.
LeslieV1 (From Parkland, Fla. (Leslie))
That's my point, Kathy. Who has time to figure all this out? Time plus bench space.
mplewinska (Magda from Miami)
Yup, it takes time and patience. And bench space. It's not for everybody.
But it's fun.
KB Barrett (Kathy in N Calif.)
Finding out homogeneity would involve what 3 generations? or 2? the cross of the parents, the 1st filial generation which the progeny may or may not be homogeneous for the trait your looking at, then a cross or those individuals to test for trueness of the trait, so 2 generations, in Phals could be 3 years of your life.
bmtorchids (Barbara)
Madga, those are the ones the breeder sells, the good monozygous they will keep for stud. I hate that.
mlp2 (mlp2 (marylou))
Leslie - it used to be that you could talk to the old timers like Roy Fields or the senior Bob Scully and they would tell you a lot about this very thing having been through it for so many years. And they did not keep EVERY thing secret. Although some did.
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Wow cool, thanks Magda. For every population that we work with, we should evaluate each participant by crossing it to itself first and then record the results. Then, the crosses to other members can be evaluated in the context of the knowledge gained from selfing. Now, we are getting somewhere - a process.
KB Barrett (Kathy in N Calif.)
That's why Rod McLellan has 'Acres of Orchids'!
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Right, Marylou, there is no need to keep all this secret. It's complicated enough so that the secrets are totally unnecessary.
LeslieV1 (From Parkland, Fla. (Leslie)
)
Too bad it's not like that today. I feel like Barbara, that the growers are selling off their mistakes, and keeping the good stuff for themselves.
mplewinska (Magda from Miami)
Kathy. Right. One cross to be sure of zygosity, then you have to breed again. Barbara. Yes, a good stud plant is known to be homozygous and the breeders guard then jealously. That's how they make a living, after all.
bmtorchids (Barbara)
That's right. I wish they stop putting a pix of the nice big bloom over the little seedlings, make you dream about some day. Just so many orchids, and so many fools.
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Kathy, you may be right but if you were to go to the chief botanist at Rod's and ask which plants were hetrozygous, I wonder if he/she could tell you. Do you think records of this are kept? I know that they should be but.....I wonder.
ChuckMyr (Chuck in Austin, MN)
But where would their breeding programs be if they sold their best stuff???
KB Barrett (Kathy in N Calif.)
Rick, Dr Wang opens his GHs to tours every Thursday. Ed Wright says 'Come on down, anytime' I'd love to see the GH's there at Texas A&M.
mlp2 (mlp2 (marylou))
A lot of commercial growers keep their secrets. And you can't really blame them. It's their stock in trade. But there is a lot of information out there. Like following the AQ's and pedigrees from Wildcatt. As I said
earlier tonight there is a lot of information from those studies that can tell you a lot. Not nearly as much as raising those acres, but a lot.
mplewinska (Magda from Miami)
Good growers don't sell junk. You just have to find a grower you trust and have a good relationship with. And you have to get to know them and get them to trust you before they will tell you their secrets. And some still won't. What can you do?
ChuckMyr (Chuck in Austin, MN)
I'm going to guess that the true species plants are relatively homozygous and hybrids have relatively high degrees of heterozygosity.
bmtorchids (Barbara)
Then they should give us the facts. Not just a temptation. But, we are only human. [They are giving you their best "guesstimate" -- many people buy 3 to 6 of a new seedling grex hoping to increase their chance of getting one of the good ones...mlg]
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Kathy, I like the idea of going to Tex. A&M and seeing the GHs. Want to go?
LeslieV1 (From Parkland, Fla. (Leslie))
How much do you have to spend before they befriend you, or trust you?
mlp2 (mlp2 (marylou))
Years ago I interviewed a top grower of Den. phals here in Miami about the culture he used. He told me he fertilized them every three days when in growth and that they cannot tolerate temps below 55 degrees. Then he made me promise not to print the information!! I later got a CCA on my Den. phal. and after he died begain to disseminate his cultural information.
KB Barrett (Kathy in N Calif.)
Rick, talk with Frank or Maynard Michaels sometime. Frank was the hybridist for Rod McLellan's. Maynard will talk your ear off about Phals. What ever happened to Uncle Earl? he lives nearby, and may know something about Onc.'s
[Uncle Earl had a hard drive crash...sure hope he gets back on line before too long! He sent me his sister's email address -- and I lost it -- hope he reads this archive and gets in touch...mlg]
mplewinska (Magda from Miami)
Chuck. I don't know that species are any more homozygous that hybrids. Heterozygosity is one mechanism living things use for keeping around spare genes that might come in handy in the future.
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
I don't beleive that growers give us junk at all. There is terrific competition to come out with the better plant all the time and that is what each one of them is trying to do. They are probably under so much pressure to produce that they don't think of what they are doing as science but just the JOB. Hence, no publications with their knowledge.
LeslieV1 (From Parkland, Fla. (Leslie))
Good for you Marylou! I feel there are too many secrets to this hobby!
mplewinska (Magda from Miami)
Leslie, what a cynic! :) I guess it depends on the grower.
bmtorchids (Barbara)
Kathy, be careful, you are going down to the Rio Grande, it is another world.
KB Barrett (Kathy in N Calif.)
Rick, Friends Fly Free on Southwest!
mplewinska (Magda from Miami)
Marylou, who was your mystery grower? Inquiring minds want to know.
KB Barrett (Kathy in N Calif.)
That's why we're going with Ed! *G* Seriously Texas A&M isn't in Waco. What town is Dr Wang's GH in Harold???
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Kathy, let's see how we can work this out. I've got some time available and could take off and I may have a way to get there on Southwest. Let's talk later about the logistics.
bmtorchids (Barbara)
Kathy, I think they are all in the Rio Grande Valley area.
mlp2 (mlp2 (marylou))
Dear friends, it was a LONG time ago.
KB Barrett (Kathy in N Calif.)
Sure! Lois may even join us!
harold6820 (Farmers Branch, TX)
A&M is in Bryan/College Station. Way south of Waco.
LeslieV1 (From Parkland, Fla. (Leslie))
Sorry, Magda, don't mean to be a cynic, but I see some of the politics involved with even buying a good orchid, it's who you know!
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Harold, what airline town is College Station near?
KB Barrett (Kathy in N Calif.)
Thanks, Harold! See? You showed up at the right time!
harold6820 (Farmers Branch, TX)
Southwest does not serve Bryan/College Station. Nearest is Houston. Then drive to CLL.
mplewinska (Magda from Miami)
Leslie, don't apologize. I've thought the same thing you said. It's true. You have to spend something. Money, time, effort, something.
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Leslie, there is always some truth to that but I think that it effect timing of availability more than anything. The good orchids will be available to the public but when is the question.
bmtorchids (Barbara)
And where is Waco?
mlp2 (mlp2 (marylou))
Actually if you buy healthy mericlones you are way ahead of what it cost when I started. Used to be min. $500 per bulb for good Catts. Modern days are better. When I buy new crosses I always older the largest seedlings available instead of the smallest (and cheapest) because I figure they are better growers being all the same age from flask. Just use your head.
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Hmmm, And I was in Houston just 3 weeks ago.
mplewinska (Magda from Miami)
If no one has any more questions for me, I think I'll call it a night. So speak up!
KB Barrett (Kathy in N Calif.)
Many times, Leslie, its efffort! If they see you're not an idiot they'll open up some.
harold6820 (Farmers Branch, TX)
Houston also has a lot of VERY good GH's.
LeslieV1 (From Parkland, Fla. (Leslie))
Magda, are you going down to Homestead the weekend before Thanksgiving to go some shopping?
mlp2 (mlp2 (marylou))
It is pretty late here Magda, and my puppies get me up early. Did enjoy my first night on safari chat line. It takes some getting used to. Come back and explain why you can breed two white catts and get lavenders!!
***[Oy! It's all explained in Northen's book. It's not really hard to understand but it is confusing and gives me a headache every time I go through it - mp]
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Magda, where do we go from here? Is there a body of knowledge to be collected from the growers? Is there something worth knowing from visiting and picking brains of these hybridizers? What is your opinion?
mplewinska (Magda from Miami)
Leslie, I was planning to go just to look around.
bmtorchids (Barbara)
Madga, it's been a nice evening, I sure learned a lots. Now if only I can use the knowledge at my next purchase...
KB Barrett (Kathy in N Calif.)
Madga, if we were to look in college libraries for information on dominance which are the most likely Universities to look at? UC Davis is near here, Texas A&M, only because of Dr Wang, and where else???? [Not just because of Dr. Wang - A&M is a renowned agricultural college...mlg]
LeslieV1 (From Parkland, Fla. (Leslie))
I am trying to network, and spend money, we'll see how it turns out.
harold6820 (Farmers Branch, TX)
Waco is 100 miles south of Dallas. Bryan is south east of Dallas, about 200 miles. Houston is about 250 miles from Dallas. Waco is enroute to Austin and San Antonio. Bryan is on the way to Houston.
ChuckMyr (Chuck in Austin, MN)
I agree, Marylou, as a Paph collector there are no mericlones available so all I can do is buy seedlings. Never sure what i'm going to get so have to look at parents. I may get a dog, or I may get the best of the flask when they are unbloomed seedlings!
ChuckMyr (Chuck in Austin, MN)
Thanks, Magda!!
mlp2 (mlp2 (marylou))
My humble opinion is that there is a wealth of information waiting for someone to compile it into a concise form. I don't believe this has actually ever been done aside from lectures for judges training, etc.
bmtorchids (Barbara)
Thanks, Harold, good to see you.
KB Barrett (Kathy in N Calif.)
Hey, the net is supposed to be the fountain of all knowlege, but most libraries have fees associated with them, which do you subscribe to and what fees are associated with those databases?
LeslieV1 (From Parkland, Fla. (Leslie))
I wish I could follow you around and pick your brain, I bet I'd learn alot! Have fun!
mplewinska (Magda from Miami)
Rick, of course you can get info from growers. Then you have to sit down with the books and collate it all and make sense out of it. Kathy, A&M might be better because they would be likely to be interested in practical things like plant breeding. But really any university is OK to start. Then once you get familiar with the materials, you'll find out where to find more.
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Kathy, I don't think that this one has been compiled yet. It's just waiting for some enterprising individuals who want to work their tails off to do it. Are you volunteering?
LeslieV1 (From Parkland, Fla. (Leslie))
Thanks, Magda!
KB Barrett (Kathy in N Calif.)
Harold, who are some good GH's in the Houston area? Are they in the AOS Almanac? (For future reference) Also, where is Anita Aldrich's Sundance Orchids? What town?
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Magda, would this be worthwhile to do? It sounds like it might be. Or, is this something that hasn't been done because it is much more complicated than meets the normal eye?
mplewinska (Magda from Miami)
I'm lucky enough to be on a university faculty, so I get to use the U of Miami library for free. Some botanical gardens will let their members use their libraries. It's hard to find reliable information on the net.
bmtorchids (Barbara)
Go for it, Rick, it's waiting for you.
KB Barrett (Kathy in N Calif.)
Heck NO! I live in California!!! Can you imagine the liability if you say pink is dominant over green and have it not be true??? YIKES!
Yes, Rick, I'm sure Timber Press would print it too!
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Sorry, Magda, for being so non-explicit (too many pronouns). I'm really talking about compiling a compendium of zygosity first and I don't know what follows, later.
mplewinska (Magda from Miami)
Rick. Compiling all the info worthwhile? I've thought about doing it just for my own information? Would people want to have it? I'm sure? Would it sell? I don't know.
harold6820 (Farmers Branch, TX)
If you want to find out about A&M and orchids, contact Dotty Woodson. Dotty is a member of FWOS and is the A&M extension agent for the Fort Worth area. She and her husband specialize in Phal's and also cool growers. D.Woodson@TAMU.edu
KB Barrett (Kathy in N Calif.)
Of course it would sell! Does Wildcatt sell? YES! Did you see the discussion about hobbyists doing their own crosses on the OLD? There are alot of people crossing their orchids out there.
kawacym
Sundance Orchids is in Galveston, Tex.
mplewinska (Magda from Miami)
Compendium of zygosity could be pretty involved. You'd have to do it plant by plant. Don't forget that if you take two plants of the same species or the same hybrid, one may be homozygous for a particular trait, the other heterozygous. The only way you'd find out is by breeding them or (maybe) by analyzing the DNA in the lab.
harold6820 (Farmers Branch, TX)
In Houston, there is Palmer Orchids. Siam Orchids (Vanda's) Anita Aldrich, Sundance orchids in Galveston just south of Houston. Just to name a few. [Orchids & Ferns in Houston...mlg]
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Thanks Harold, I may just contact Dotty. Especially if Kathy and I decide to take a couple of days and come down there to meet with Dr. Wang. Kathy might wimp out (being from California *G*) so I may have to come down there alone *big G*
LeslieV1 (From Parkland, Fla. (Leslie))
My typing is getting quite sloppy, and I'm getting tired. It's been a pleasure Magda. Goodnight everyone!
KB Barrett (Kathy in N Calif.)
OOOH! Them's fighting words McGee! VBG!!
mplewinska (Magda from Miami)
Well, I go to go take care of my sick kitty. If everyone has lots more questions, maybe we can do this again sometime. Goodnight.
harold6820 (Farmers Branch, TX)
You come thru Dallas on the way in either direction, call me and I will show you several GH's in the Dallas, Ft Worth area. Advance notice will make me more flexible. [Count me in on that ramble!...mlg]
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Sounds like what I feared, Magda. A compendium of zygosity probably doesn't exist yet because it is a bit too complicated to just publish. It sounds like a lifework!
KB Barrett (Kathy in N Calif.)
Watch it Harold! I've been taken by all you southern gentlemen before! You are all so kind its enough to make this California girl pull up stakes and move there. You have two of the four basic food groups, chili and BBQ, plus no state Income tax!
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Magda, thank you for all the good information. This has been a wonderful chat.
runnerRick (Rick in Concord, CA. Diablo View OS, Cal OS, AOS)
Ok, I'm out of here. Kathy, we need to talk so, maybe at the board meeting we could chat about this some more. This could be interesting!
KB Barrett (Kathy in N Calif.)
Well, all it's been a great evening, but I've got to go. See you all on Wed.
harold6820 (Farmers Branch, TX)
Actually, you could probably spend 2-3 days visiting all the GH's in Dallas and Ft. Worth. Then there are the commercial folks.
This time, gone for real. Nite all.
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PLOIDY COMMENTS
Tue, 18 Nov 1997 20:21:20 -0500
From: Bob & LynnWellenstein
Subject: Re: Genetics
Just read the transcript of the genetics session, and felt that I might be able to add to a few points that weren't able to be completely covered in the flurry of chat.
There was a lot of discussion of 4N plants, the hows, whys, etc. It should be pointed out that 4N plants do occur naturally at a very low rate. There may be competative disadvantages to polyploid plants such as slower growth in a tropical environment, but are probably advantages in high stress environments such as dry or extremely cold environments, where higher percentages of such plants naturally exist. Most of our cultivated orchids that are 4N are purposely induced using colchicine or other mitotic inhibitors (basically herbicides used in low doses), others are the result of somaclonal mutation resulting from tissue culture
conditions. The use of colchicine was brought up and warnings issued appropriately about its dangers to the user, I would also add that you have to consider safe disposal of it also if you use it.
4N plants are useful because of increased fertility in wider ranging crosses, and in many cases also produce larger and more darkly colored flowers. The recent successes with Phragmipediums by the Eric Young Foundation are certainly an excellent example of this effect, essentially the cells of a polyploid plant are larger, so the same number of cells makes for a larger, thicker flower. While Phrags, Odonts and Cymbidiums have responded very positively to conversion, successes have been lesser to date in some other genera. A point to be remembered is that there is no guarantee that you will end up with 4N, you may also produce aneuploid plants if the technique is not refined for the plants you are working with, and the results of this may be plants with both growing and flowering problems.
Colchicine treatment is usually performed at the protocorm stage just before or at the stage of formation of the primordial leaf, ie a slightly pointy protocorm. The protocorms will be exposed to colchicine in low concentration for several days, and then transfered to a recovery medium. As stated losses can be high. Also as stated, the only certain way to tell if a plant is 4N is to karyotype it, that is make a squash of cells from a growing root tip, hope that you are lucky enough to catch a cell at the correct stage of mitosis to observe the chromosomes in the stained prep with a microscope, and then performing a count. There has been work with Paphs correlating stoma size with ploidy, and this is a useful tool to determine if a plant is polyploid, but not to determine an exact chromosome number.
As useful and horticulturally desirable as 4N converted plants can be there are some breeding drawbacks also. One is in trying to fix a desirable recessive trait. Let's take for example a cross of a yellow Phrag. besseae with a normal Phrag. sargentianum, and you get all normal colored progeny Phrag. Mem Dick Clements (assuming that the yellow besseaes behave as an anthocyanin pathway defect does in Paphs - a simple recessive, a big assumption but made for the sake of example). If you leave these plants as diploids (Aa x Aa) and sib them, you have a one in four chance of producing a yellow Mem Dick Clements, but if you have converted them to 4N (AAaa x AAaa) you have dramatically lowered the potential number of expressed recessives (you do the math :-) ).
A number of people expressed an interest in where they can learn more about the ploidy issue. I would suggest a starting point be "The Orchids: Scientific Studies", edited by Carl Withner. It is not light reading, but gives an excellent overview of ploidy issues in orchids.
A note about ploidy shift in tissue culture (meristeming) is also in order. If a plant is converted from 2N to 4N (or any other ploidy) during meristeming, it is no longer considered, under the rules of orchid naming and nomenclature, to be the same clone. For example, when the 2N Slc. Beaufort 'Elmwood' was meristemed, several 4N clones (such as the 'UT 5' clone) were generated, which are no longer considered
to be the 'Elmwood' clone.
Regards, Bob
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