Hello!

I am very much interested in Poncirus hybrids. And these days I got the question whether somebody has ever crossed a sugar orange - I mean an acid-free one - with poncirus. Has somebody heard about that? In my fantasy such a cross tastes somewhat nasty but with a good mixture of sourness and sweetness.

Greetings,

Till

As far as I know the acidless gene has been studied in Pumello, probably the same gene is determining the lack of acidity in acidless oranges. This gene is recessive, that is you will need to cross primary poncirus hybrid again to "sugar orange" to obtain lack of acid.

Hello Ilya,

thank you for the information. Hmm, that means of course that my idea will not function. It would be interesting though to have an acidless Segentrange. But that is actually not what I hoped for. I hoped the gene is intermediary. I think a little bit acid would be fine.

Greetings,

Till

Poncirus is not "sour", it is just plain nasty.

Poncirus "flying dragon" seems to be the most palatable ? Maybe a good choice as one parent.
Various Citranges are rated more or less edible, some more acceptable than others. Most of these are different crosses of Poncirus and orange, mandarin, so your cross may be worth trying.

Probably every taste bud and every plant are different, but of the 3 Poncirus plants I tasted fruit from this year, the Flying Dragon fruits tasted the worst to me. Maybe it is also highly related to when picked, where grown, how long after picked...wasn't a rigid evaluation.

For me the odor of poncirus peel is quite pleasant. On the contrary, the smell of most citranges is awfully nasty.
The biggest problem with the taste of poncirus fruit is the presence of essential oils inside it. One can accustom to its acidity or bitterness, but not to the oil of turpentine.

Till,
I have also been thinking for some time about attempting to cross an acidless orange with Poncirus. Trouble is I haven't actually got an acidless orange!
However, I have been investigating sources for 'Vaniglia Sanguigno' and I hope to obtain one this spring.
The difficulty then is to have flowers on both plants at the same time, so that the pollen is viable and the stigma receptive.
The original Webber citranges were with orange pollen on to a Poncirus flower. However, the reverse hybridization will be more obvious in seedlings that show the trifoliate trait. So that's what I'm aiming for.
As I'm not exactly a youngster. the real difficulty will be surviving long enough to see any results.
Mike/Citrange

I have acidless orange Gosset from Baches. Actually, the pollen can be kept dry and frozen for quite a time.

Yes, I have read that pollen can be stored in this way.
But, for an amateur rather than a research centre laboratory, it adds another set of variables which could result in failure. How long to store, what temperature, how to keep dry, how to stop my wife throwing out a foreign object in the fridge! Much easier if the plants were kind enough to flower at the same time!

A good mealtime to all!

I am impressed by the many answers! And yes, although I dreamt from a half sour and half sweet citrange, a kind of "normal" tasting fruit, it would be great to have a sugar citrange or segentrange, also. It would be something new and perhaps not too bad tasting.

The terpentine... Yes, its really nasty. But I agree to IlyaC that Poncirus has some potential. The smell - aside from the resin aroma - is quite good, even better than in most citrus fruits which have no smell at all, at least for my nouse. The taste of citranges. Well... But we had some good results from backcrosses. And when I rightly remember Swingle, who made a lot of crosses and backcrosses, then he wrote that all Segentranges were thrown away not because of bitterness but because they were too sour for the market. And he wrote that some backcrosses had a resin aroma, i. e. not all of them. We loose frost hardiness by backcrosses but we may retain -10°C what is something, for Brittain even enough in most years.

The pollen problem is not too great, I think. Everyone who wants to cross needs pollen to be stored. Otherwise we depend on chance too much. Not all the pollen must be fertile. Given the great amount of pollen grains, it is enough when 1/4 is still viable. And the storage time needs not be long for pollen. Poncirus flowers every year in spring. A good orange tree also flowers every year. If it does so in summer than we must only bridge a few months. And we can work with tricks. We can store a poncirus branch in the fridge and graft it on a tree in June so that it flowers in July, or so.
The greater problem will be that orange trees are highly polyembryonic. So I would prefer to pollinate poncirus with orange pollen. That may make a longer storage time for pollen. But it will be ok. The problem is indeed to recognize hybrids. I have no experience in that. But I suspect that hybrids grow faster and have different leafs at least sometimes.

I am also lacking a sugar orange. But I know were to get it. If the plan stands I have one in spring / summer. So lets begin?

What regards greater dreams: I would like to produce a kind of poncirus without poncirin. Therefore I plan to backcross the best tasting poncirus hybrids (especially Swingle5*) with poncirus in order to enhance frost hardiness and to make them decidious again. Then I want to cross the hybrids by selfing in order to get rid of the poncirin - hopefully. I think that is something worth trying, though it will cost me at least 10 years, if I manage to bring the plants to flowers by some tricks, the workability of which I still have to test. Because I what to come to some good results inbetween so that by patience is not too much tested I plan to also cross Chansha with Keraij, hoping for a hardy mandarine that ripens earlier, I want to cross Citrandarin with Keraij and finally blood oranges with Chansha. Well, great plans for my small plants! But without plans we will not come further and will still grown the same old citranges in another hundred years. So I set before myself to make crosses with every flower my plants will get. The fruits of the flowers will be the same. But I have more to play.

And if some of us cooperate who knows what comes out of it. It will probably not be a great fruit but another step towards that aim and most probably something better than just an ornamental. The rest, who knows, is for our children. I am 32 now. So if God wills there is time to do something. What regards the older of us: Isn't it a hobby? So the way is in way also the goal. We should not get stuck in our plans. Everybody, young or old, should remain gracious, being ready to give his plans in other hands. But we can play as long as we live. And who knows? Should we reach heaven before our plants are out of their "puberty" maybe we will see the ideal citrus plant there. - I doubt, however, that they have frost there . They may be a little bit frustrating for every breeder aiming at frost hardiness, I admitt.

Greetings,

Till

Till,
I wonder if you know that US119 is a hybrid between citrumelo and acidless orange Succory?

Also, it seems that crossing poncirus hybrids with fortunella or C.ichangensis gives progeny without poncirin.

For the hardiness: I believe that in order to obtain a really hardy and eadible citrus we need to keep the minimal distance from poncirus or ichangensis, that is to cross citranges or citrumelos between them.
Theoretically, with sufficient number of hybrid zygotic seedlings one can select a plant retaining all genes responsible for poncirus hardiness and producing orange like fruits.

Hello Ilya,

no, I was not aware that US199 goes back to an acidless orange. Interesting. I take it as an encouragement that acidless oranges perhaps do reduce acidity even though the gene for the lack of acidity is recessive.

What regards forst hardiness: That Ichangiensis reduces Poncirin is quite interesting. It would be interesting to see what happens if we cross an Ichangiensis hybrid with a citrange and directly with Poncirus. And also what happens if we cross an Fortunella hybrid with Poncirus. Poncirus x Fortunella is very difficult as Swingle wrote. Crossing citrange (or citrumelo) with Citrange (or citrumelo) has one disadvantage, however: When only one cromosome set produces Poncirin then we will have a nasty fruit although the frost hardiness may be very good. What the genetic nature of a hybrid is like will only become obvious when we produce a second generation with sufficient plants by selfing. That is what I wanted to do although that costs a lot of time. It might be more motivating to cross a good tasting segentrange with a citrange for then the probability is greater that Poncirin is absent. However, the frost hardiness may not be good enough. But lets try to back cross Ichangiensis hybrids with Poncirus. I hope to produce acidless orange x Poncirus hybrids meanwhile.

Greetings,

Till

Hello Till,
N1triVoss is supposed to be a hybrid between Ponciris and C.ichangensis; I have not tested yet its fruits, but it seems it has no poncirus taste.
The biochemistry of flavonoid glycosids like poncirin is very complex; many enzymes can affect their presence or give the very different end products.
The flavonoid precursor to poncirin is present also in grapefruits and even oranges but the final steps in biosynthesis are different from that of poncirus.
Poncirin is responsible for the bitter taste of poncirus fruits, the smell and sticky disgusting taste are associated with poncirus specific essential oils, not with poncirin.
Concerning hybrids with kumquats: citrangequat Thomasville is a cross between Willits citrange and F.margarita, it has no poncirus flavor.

I can confirm that N1TriVoss has no poncirin taste. The juice tastes like lemon but not the rind that is not usable.