Do we know what happened to this interesting hybrid?
I has not be able to find any further information on it.
In  leaf freeze resistance tests it was shown to have a similiar or even better hardiness than US119.

http://hortsci.ashspublications.org/content/33/4/744.full.pdf

But I remember that Ilya posted at old forum article, that unshiu mandarins do not hybridize and cross pollination with poncirus is only used to obtain seeds to get nucellar seedlings, or mutants. So it is possible that plant mentioned above is chimera, or mutant.

It is not a case, pollination with foreign pollen is used to enhance seed  formation in satsuma.
Poncirus is used because  its hybrids with satsuma having three leaflets are easily distinguished from   nucellar seedlings that are screened for for new traits emerging through natural somatic mutagenesis.

Thank you Sylvain,
Your tree is huge and magnificent.
From what you presented it is clear it is a chimera between poncirus and pure satsuma.
Where you did got the budwood from?

Sylvain,
Have you been able to germinate its seeds?

It is believed for a long time to be a chimera, but its origin is very obscure.
It is either originated in Abkhazia region of the USSR or  in  Prague, Czechoslovakia.
In USSR several attempts were made to produce poncirus/citrus chimera by the induction  and subsequent regeneration of massive callus at the grafting point.
By this, they believed to produce  plants containing cells from two species (chimeras). Most of such plants are unstable, giving branches of pure species, but occasionally a stable, so called periclinal chimera can be produced.
In the recent study   Czech scientists  isolated the cell nuclei from this plant, stained their genetic material (DNA) by fluorescent die and determined the intensity of fluorescence signal from individual nuclei. Since the genome of different citruses is slightly different in size, they hopped to see two peaks of fluorescent intensity if it is satsuma/poncirus chimera.
They observed only one, so it is either not a chimera  but a hybrid or   chimera  between poncirus  with some hybrid having approximately the  same  genome size as poncirus.
I guess only molecular markers can definitely  resolve the origin of this very strange plant.

Millet,
Its origin is not yet clear. Leaves are  a mixture of bi- tri- or monofoliates.
The fruits are almost satsuma like, no poncirus smell or taste.
There is    suspicion that it is a chimera between poncirus and satsuma, but strangely enough even stems and leaves do not have odor or taste of poncirus.
Scientists in Brno show that the nuclei from its cells have homogeneous DNA content, that does not definitely  proves an absence of chimerism , but points more to the hybrid origin of this citrus.
On the other hand, Roberto from Wien observed an emergence of  poncirus like branch   distantly  from   grafting point.
It could be some second generation poncirus-satsuma hybrid with unstable genome, but no definite proof for this exists for the moment.

Thank you, very nice looking fruit.
Hope your plant will survive, at least one branch seems not much affected.

Yes, small plants do have very dangerous long thorns, but on fruiting branches they are either small or do not exist at all.

Where did you get it from?
Original 6-7-2 is monoebryonic, so ichangquat from B.Voss known by this name in Europe is  F2 seedling different from mother plant. Theoretically your plant could be another seedling of 6-7-2 from USA.

I think the reason why it is not being used as rootstock is the variability of its seedlings,  they are zygotic and do not reproduce faithfully the mother plant.

It seems it can be peeled rather easily:



Google translation of the Italian discussion:
http://translate.google.com/translate?hl=fr&sl=auto&tl=en&u=http%3A%2F%2Fwww.fruttama.it%2Fforum%2Fviewtopic.php%3Ff%3D10%26t%3D783&sandbox=1

Selkirk,
Fruits of your Bloomsweet look more  like mine:



http://tropicalfruitforum.com/index.php?topic=18992.25

Do you have many seeds inside?

Recently in France   a mix of rosé wine with grapefruit juice become rather popular.