As I have found, there is quite a lot of pigmented citruses fans, so I decide to open new topic of new pigmented hybrids.
There are two main lines in crossbreeding of pigmented hybrids in Italy.
First, there are so-called OTA hybrids - hybrids between clementine and Tarocco, included OTA9 , OTA14, OTA23 etc.
Second, there are so-called OMO hybrids - crosses between clementine and Moro, included OMO6 , OMO31 etc.

source of image
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3336134/
In this article you can find everything about blood oranges history and their hybrids.: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3336134/

According to this article:

"....hybrids between clementine and Moro (OMO) and clementine and Tarocco (OTA), produced in the experimental orchard of the Centro di Ricerca per l'Agrumicoltura e le Colture Mediterranee - CRA ... displayed a range of pigmentation levels when grown under equivalent conditions, from very high pigmentation (OTA9), medium pigmentation (OMO6, OTA23, OMO31, and OMO15), and low pigmentation (OMO28, OTA14, and OTA20) through to no pigmentation (OTA41, OMO3, OMO5, OTA11, OTA17, OTA31, and OTA35). ..."

Thanks Rad. I'm going to experiment with some hybridizing this year. Now if I could just get my Smith red to fruiting size... I also have Moro and a few other blood oranges.

http://www.citrusvariety.ucr.edu/citrus/smithred.html

Interesting,
According to this paper the old Italian varieties Maltaise Sanguine and Sanguinelli are periclinal chimeras with the respect of the position of the element responsible for red color.

The Tarocco is not very pigmented. The Moro & Smith have much better pigmentation.

How about the bream tarocco? Seems very pigmented on the "citrus pages" web site...


Interesting subject by the way!

Yes, the "bream" is very pigmented if you leave it on the tree forever. I just don't have any patience to wait so long.

I just tried one of my standard tarocco's, they are already sweet, but very little blood. A few flecks of pigmentation is all they have right now.

Bream, a Tarocco Mutation ... very interesting.

Liked the seeds ...

Laaz, how do you like the smith red? I've been thinking of getting one from four winds growers, but never heard any opinions on taste.

So tell me, What does the "O" in OTA and OMO stand for? - Millet

Radoslav, thank you. - Millet

In this paper they found that red color in Italian blood oranges was due to the activation of the gene regulating formation of anthocyanine pigments.
This activation is caused by the integration of retroposon (sort of internal genomic virus). This element was not stable and subsequently was shorten that gave it the stronger capacity for coloration. Typical Tarocco had the long form of it, while Moro used to create hybrids with Clementine contained the shorter one.
They also found that older Sicilian blood oranges that subsequently gave rise to Tarocco , Moro and the rest of Mediterranean blood oranges, are periclinal chimeras containing separately both shorter and longer transposon forms in cells coming from L1 and L2/L3 embryonic layers.
Another example of periclinal chimeras is stably variegated plants, but in this case, one of the embryonic layers contains cells that are not able to make chlorophyll.

Yes, variegation is a lack of chlorophyll, as one famous czech botanist said," I am against propagation of variegated plants - it is like reproducing animals with half of the stomach." - And this is, why I am not a big fan of variegated plants too, but I have to say, that some of them are realy nice.