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11-07-2008, 12:48 PM
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Join Date: Oct 2007
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Quote:
Originally Posted by Andrew
The idea of a blue gene is a bit miseading. The blue pigment in plants can be produced by a several of types anthocyanins, the same chemicals that produce red pigments in plants. Hydroxylation and dehydroxylation of anthocyanins shifts their colour between red and blue in the presence of certain cofactors. Thus lack of blue flowers in nature does not necessarily represent the lack of a blue gene in non-blue plants but rather the difficulty in getting plant cells to drive the hydroxylation of anthocyanins into their blue state.
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I agree with what you say and I think I should have been more precise when I wrote about blue genes. What I meant was that the gene coding for an important enzyme (a flavonoid hydroxylase) in the biosynthetic pathway of the flavonoid pigments was missing is certain plants.(such as the rose) Without this enzyme there is no way for the plant to synthesize the blue pigment delphinidin from the anthocyanins which gives the true blue color in plants with a high cellular pH. At best the color would be the purple shade of blue.
Please correct me if you think I am wrong! We only touched on this subject briefly in a class last year, so I do not have a very in depth knowledge of the subject.
I have heard that phal breeders are working to select plants with higher cellular pH, so that they can make the purples blues look more like a true blue. I hope they suceed, a true blue phal would be amazing to see!
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Camille
Completely orchid obsessed and loving every minute of it....
My Orchid Photos
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11-08-2008, 03:36 PM
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Join Date: Oct 2008
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Wow, thanks for all the great info on the way color is expressed. There are some smart people in here.
Even though it is still not the blue I am looking for, I am intrigued by the Cleisocentron - merillianum linked to in Mels post. It is kind of expensive for what I normally like to spend though. Any comments on how easy it is to grow.
I grow indoors under T5 lights. I live in New Mexico and even though I have them in a room with a 24/7 humidifier, low humidity can be an issue for me (although for the most part it at least stays above 50%).
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11-08-2008, 06:34 PM
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If I'm not mistaken, delphinidin is the anthocyanin that is "true blue", and it does not exist in orchids.
Here's a shot of the bluest orchid I've ever seen: a really nice Dendrobium gonzalesii cultivar I saw at Parkside:
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11-08-2008, 11:25 PM
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Now that is blue!
Isn't there a couple of Zygopetalums that are blue?
The term coerula refers to blue in a orchid. A lot of varieties of plants have been called coerula when they are, in fact, lavender and it is probably nothing more than a way of promoting a plant for marketing purposes. A lot of people collect these co-called blue orchids and pay huge prices for them.
Is this blue? Darwinara Charm 'Blue Star'
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11-09-2008, 11:45 PM
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Where in LA is Morning Star and how do you get in contact with them? Thanks!
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01-15-2010, 09:13 PM
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01-15-2010, 10:36 PM
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Quote:
Originally Posted by jbsquared1
Where in LA is Morning Star and how do you get in contact with them? Thanks!
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Thibodaux. Here's their website: Home
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Sarah
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01-15-2010, 11:01 PM
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Quote:
Originally Posted by Pure_Passion
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Those flowers are dyed blue. They're not on living plants. These are from the cut flower trade.
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01-16-2010, 02:56 PM
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Quote:
Originally Posted by camille1585
Inserting the blue gene (in this case using the delphinidin gene from delphiniums or petunias) is not enough. They first had to 'turn off' the gene responsible for red pigment in order to get blue. However the blue is not perfect, because the pH of the petals (more technically, the pH of the vacuoles in the cells) affects colors. If it's too acidic, the color is more purplish. That and other complexities means that biochemically speaking, blue flowers are hard to get, even if the gene is in a plant and being expressed.
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Quote:
Originally Posted by Andrew
The idea of a blue gene is a bit miseading. The blue pigment in plants can be produced by a several of types anthocyanins, the same chemicals that produce red pigments in plants. Hydroxylation and dehydroxylation of anthocyanins shifts their colour between red and blue in the presence of certain cofactors. Thus lack of blue flowers in nature does not necessarily represent the lack of a blue gene in non-blue plants but rather the difficulty in getting plant cells to drive the hydroxylation of anthocyanins into their blue state.
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Quote:
Originally Posted by camille1585
What I meant was that the gene coding for an important enzyme (a flavonoid hydroxylase) in the biosynthetic pathway of the flavonoid pigments was missing is certain plants.(such as the rose) Without this enzyme there is no way for the plant to synthesize the blue pigment delphinidin from the anthocyanins which gives the true blue color in plants with a high cellular pH. At best the color would be the purple shade of blue.
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I won't try to speak for anyone else but I found that whole discussion quite interesting! Thank you, both of you!
So on a slight deviation from orchids, is "the pH of the vacuoles in the cells" then what accounts for the color of hydrangea flowers? ... That their vacuole pH is highly affected by the soil pH?
Quote:
Originally Posted by camille1585
I think I read somewhere that a study was done that showed that honeybees can't tell blue and green apart, so from a plant's perspective, why put in the effort to make the complex blue color when the bee can't even see it?? Don't know about other insects. I'm somewhat dubious about this theory though.
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I agree, that does seem rather unlikely, and if true really would surprise me. if you happen to come across more info on that let me know.
Quote:
Originally Posted by Undergrounder
I think some of you guys are being very 'blueist'.. I've seen plenty of orchids that i would call 'blue', not 'purple'...
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LOL, I will fully admit, Undergrounder, that I am definitely a "blueist". If someone is going to claim an orchid is 'blue' then I expect it to be BLUE -- not blue-purple, blue-lavender, etc. Anything less is 'false advertising'.
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