genetic color distribution....REVISED

So sorry for the revision, DG won't let me edit all my posts and I might have confused people with genetics. I deeply apologize and I hope you guys forgive me -_-. I can't wait every 24 hours to edit my posts from this thread:http://davesgarden.com/community/forums/t/914051/ I'm really sorry for the messy stuff (I'm bad at teaching i know lol).

Starting from the beginning....

This is just a simplistic, hypothetical explanation of colours in Ipomoea (Not set in stone, plust there are many modifier, mutable, etc. genes that must be considered).

Source: Morita, Yasumasa (2005) et. al. Japanese morning glory dusky mutants displaying reddish-brown or purplish-gray flowers are deficient in a novel glycosylation enzyme for anthocyanin biosynthesis, UDP-glucose:anthocyanidin 3-O-glucoside-2''-Oglucosyltransferase, due to 4-bp insertions in the gene. The Plant Journal, 42: pp. 353-363.

"The Japanese morning glory (Ipomoea nil) displays bright blue flowers (Figure 1b) that contain the peonidin (3¢-methylcyanidin) 3-O-sophoroside derivative named Heavenly Blue Anthocyanin (HBA) (Figure 1f; Kondo et al., 1987; Lu et al., 1992), and a number of spontaneous mutants exhibiting various flower colors have been isolated since the 17thcentury (Iida et al., 1999, 2004; Imai, 1927). Genetic studies on the color of I. nil have shown that blue flower coloration was mainly controlled by two genetic loci, Magenta and Purple (Hagiwara, 1931; Imai, 1931). Recessive magenta and purple mutants bloom magenta and purple flowers, respectively, and double mutants carrying both magenta and purple alleles display red flowers (Figure 1d)... Among the various colors of I. nil flowers, the most favorite hue for Japanese floriculturists has been reddish-brown or purplishgray petals (Figure 1c,e) since the early 19th century, and the flower coloration is caused by recessive dusky mutations (Hagiwara, 1956; Imai, 1931)...Although their flower coloration may subtly vary due to various genetic backgrounds, the dusky mutants carrying the wild-type Magenta allele generally exhibit bluish or purplish-gray flowers that contain cyanidin derivatives, whereas those with the magenta mutation tend to display reddish-brown flowers that contain pelargonidin derivatives, as represented in Figure 1(c,e). Among them, Magenta plants with the wild-type Purple or Purple-revertant allele show a tendency to produce more bluish-gray flowers than those with the purple mutation. Similarly, magenta mutants with the Purple or Purple-revertant allele generally exhibit darker reddish-brown flowers than those with the purple mutation."
Taken from Morita (2005) pg. 355

According on the quote above, Ipomoea nil alleles are as follow:

Mg = wild-magenta
Pr = purple
mg = recessive magenta
pr = recessive purple

DY = Dusky
dy =dusky

Genotypes with DY mutation:

MgPr = Blue blooms.
Mgpr = Purple blooms
mgPr = Magenta blooms
mgpr = Red blooms

Genotypes with dy mutation (this includes dy-1 and dy-2; see chart below):
MgPr = Darker blueish-grayish-purplish blooms.
Mgpr = Lighter blueish-grayish-purplish blooms.
mgPr = Darker reddish-brown blooms.
mgpr = Lighter reddish-brown blooms.

From the first thread http://davesgarden.com/community/forums/t/914051/, I used the punette square. HOWEVER, this should not be the case as our Mg and Pr alleles work together from two different loci/location to give us the color blue, purple, magenta or red with the DY allele. Basically, the alleles Mg and Pr CANNOT be separated.

When the Punette square is used, Mg and Pr alleles are separated and recombined (I think I'm being redundant here. I want to make sure you guys get the concept; because I didn't notice this at first and this could lead to a big mess).

We can still somewhat predict the outcome of two crosses.

For instance, we can use Scarlet O Hara with a known genotype of mgpr with DY (from the chart; notice I did not write mg-1pr-m1, we will not go in depth as molecular biology here) to determine the genotype of an unknown cultivar OR to get an idea of colour possibilities if hybridizing.

Example: I'm going to use this image from the mg forum: http://davesgarden.com/community/forums/fp.php?pid=5272869
Let's say I have this flower and this is what I see in real life (not in photos). By looking at the chart http://davesgarden.com/community/forums/fp.php?pid=5686229 and comparing the picture of the intense purple mg, AND the written info about PURPLE BLOOMS, we can assume that this purple flower will most likely have a genotype of:

1. Mgpr OR
2. mgPr

Reasoning why I picked these genotypes as possibilities:

1. Mgpr
- According to the allele description, Mgpr have purple blooms in the DY series

2. mgPr
- If you look at the chart http://davesgarden.com/community/forums/fp.php?pid=5686229 and under the category "Line", you see the name "Violet". The hue looks similar to the bloom in question.

Now let's cross it with our known Scarlet o Hara (mgpr):

mgpr x Mgpr
Possible offspring genotypes: mgpr AND/OR Mgpr
Therefore, you can have RED coloured blooms and/or PURPLE coloured blooms

mgpr x mgPr
Possible offspring genotypes: mgpr AND/OR mgPr
Therefore, you can have RED coloured blooms and/or MAGENTA coloured blooms

This might look similar to the Punette square: main difference is that the Mg and Pr alleles were never separated thus not resulting in a Mgmg or Prpp combination (Just imagine if you have Mgmg genotype...what colour would that turn out? This is why we couldn't answer what colour these genotypes would turn out).

Another difference is the ratio of genotypes and phenotypes: completely different from Mendelian genetics (which you can use Punette square to).

Bluespiral from the older thread posted this link: http://en.wikipedia.org/wiki/Botany (Thank you again for the help =D)

More on the DY, dy-1, and dy-2 soon (these are the genes that produces "chocolate" blooms)...There seem to be some conflicting ideas about this and how their alleles are called. .

welcome, Eliz :)

I need to get back to this thread - very much appreciate your doing this.

Karen

(Figure 1b) Bright blue flowers, MgPr
(Figure 1c) Purplish gray flowers/dusky mutation, Mgpr
(Figure 1d) Red flowers, mgpr
(Figure 1e) Reddish brown flowers/dusky mutation, mgPr

I wonder if there is any information online about the genes that are part of the genotype for the various JMG cultivars that are currently available. For example, which genes are found in JMG 'Heian no Akatsuki' or any of the other ones.

Scarlett O'Hara's in the chart, table 1. http://davesgarden.com/community/forums/t/383743/
Akatsuki no Yume? maybe Rose silk??? http://davesgarden.com/community/forums/t/383743/

I'd like to get my hands on the darkest bloom heheheh.

I think they (Japanese) have genetic info for most cultivars, but it's kinda tricky to decipher since

1. Naming here in North America is not AS standardized as it is in Japan
2. Crossing of mgs here - too many variants

This article only uses I. nil genetic info to explain biochemical phenomenons, I tried finding an extensive article on genotypes of I. nils but can't find any =(

This message was edited Nov 8, 2008 11:25 AM

So I read the article by Morita again and I should have noticed this in his figures and tables...
Recap:
http://davesgarden.com/community/forums/p.php?pid=5691348

Figure 1b and 1d do not have the dusky mutations (dy-1 and dy-2). Figure 1b is "Blue" and Figure 1d is "Red" (Figure 1d is actually Scarlett O'Hara according to the article).

Now you got 1c and 1e that carries the dusky mutations.

At the bottom of each flower colour are actually the cells of mgs under a microscope. Notice that 1c and 1e have black "globules" inside their cells and according to this article, those exhibiting the dusky mutations have these globules. Problem is that this article did not have a "methods" section, which science articles from peer-reviewed journals usually have. Under this methods section would usually state what kind of microscope was used, stains and scales (actually, those figures should have the scale on the right but I really don't know why the authors did not include them). Now if somebody has access to microscopes heheheheh

"Grays" and "Chocolates" arise from these dusky mutations (I believe along with the gene for dilute - dy-2 and the dilute gene works together from what I've been reading).

There might also be some kind of relationship between dy-2 and yellow-green leaves (denoted by "-" under the second last column: "+" for green leaves and "-" for yellow-green). This relationship might have been stated in alot of websites, just can't find it (sorry -_-). That's why they say that the colour of the leaves can be a useful tool for hybridization perhaps because of this relationship? I've only been growing I. nils for a couple of months and I cannot tell the difference between green leaves and yellow leaves - there seem to be not a clear distinction unless what you're comparing are both on the opposite side of the spectrum =/. So if there are any inputs/hints/tips on this it'll be great if you guys post it here on this thread link http://davesgarden.com/community/forums/t/920138/

This message was edited Nov 8, 2008 11:29 AM

http://74.125.93.104/translate_c?hl=en&sl=ja&tl=en&u=http://mg.biology.kyushu-u.ac.jp/mg-files/flowercolor/flower-color.html&usg=ALkJrhhEyhIZso8uxw5t7RHknn_zZa1wow

scroll down at the bottom and there are examples of dy, dk-1, dk-2 and di. This is from a different source. Note that the journal article and the website uses different alleles to denote certain characteristic. If somebody could clarify this and give us the updated version (what is used today). I looked up the journal article alleles on the website's gene list but they seem to not have them.

Journal article alleles: DY, dy-1, dy-2
Website alleles: dy, dk-1, dk-2, di (di is an additional allele compared to the journal article's)

You mentioned:

"Note that the journal article and the website uses different alleles to denote certain characteristic. If somebody could clarify this and give us the updated version (what is used today). I looked up the journal article alleles on the website's gene list but they seem to not have them."

Apparently these may not be as standardized as you might have anticipated...

Hey all! I have just now read this post.....thanks to a DM bluespiral sent me back in November of last year (which I also just read!) ...obvioulsy, I have been absent!

When I first read this article in 2007, it was helpful in realizing the vast colors expressed with in a basic genotype....( in this article - magenta, purple and dusky) meaning that there are obviously very many additional factors involved in the color alone of our lovely flowers.

Just a couple quick points I'd like to make:

- each of the alleles discussed (mg, pr, and dy) are located on different chromosomes and therefore do segregate independently. A punnett square used to project recombination possibilities of just these three rapidly gets complex, particularly when considering heterozygotes (mgMG, prPR or dyDY)!

- mention was made of the confusion of terminology of the brown/gray modifiers... dy and dk. Actually they are two different and separate alleles. This article discusses dy which is called dusky. It is located on chromosome 3, and seems to be considered the primary modifier in the browns and grays we seek. The allele dk is called duskish and is located on chromosome 10. It seems to cause color modifications similar to dy, but not as pronounced.

Eliz, thanks for opening the discussion of the article. ...it is the details like this that for some folks adds to the experience of growing these plants! - Arlan

I located a re-issue of Ridgway's book on Amazon.com. I don't think the publisher will make it an electronic format since they didn't answer my question. It appears it could be a nice standardized tool to use in describing a plant stem, leaf and flower color.

Here is an example of what the color chips look like in the book.