Tropical Fruit Forum - International Tropical Fruit Growers

Kumin, I am looking forward how your plans succeed. I would also try to cross your hardy seedling with Poncirus hybrids. When you have the potential for mass selection then use it. Crossing with citrus would compromize hardiness too much I think. But edible Changsha hybrids, as Mikkel suggest, seems to be reasonable, too, although I fear that would also weaken hardiness. Depends on how many generations you plan. At your growing conditions, 3 generations seem to be reasonable.

My experience with producing hybrids is much more limited than Ilya's. I used emong others the nucellar varieties Limequat, Calamondin, Vainiglia Sanguigno (an orange), Poncirus and Yuzu as mother plants. I would like to encourage everybody who is interested in hybridizing to just try combinations. Plants that usually produce nucellar seeds can also produce hybrids.
Calamondin x Poncirus is easy. There are a number of hybrids in polyembryonic seeds and a very small number of monoembryonic seeds with yellow colour (normal is green). It is interesting that the same Calamondin tree can produce (yellow) monoembryonic seeds, (green) seeds with few embryos, seeds with one yellow and some green embryos and (green) seeds overloaded with embryos. All seedlings that did not have trifoliate leaves looked exactly the same and were probably nucellar. That means Calamondin seems to produce only nucellar seeds, except it is pollinate by Poncirus (or certain other species that I did not test).
Yuzu x Poncirus gave rise to one hybrid (most seeds were lost :-(, I think there were more hybrids). Limquat x Poncirus results in an resonable number of hybrids. Limquat x Swingle5Star seems to lead to even more hybrids (tests not finished). I got one hybrid of Vainiglia Sanguigno x Poncirus out of a hugh number of pollinated flowers (sadly to say: the seedling died). Poncirus as motherplant almost compliedly failed, but last year one Poncirus tree was sucessfully crossed with Rusk Citrange (a few hybrids are already discernable).
It makes more fun to use motherplants that have mostly zygotic seeds but you should just try to use others also. Don't be disappointed but be always of good hope. As Ilya wrote the number of zygotic seeds also depends on the pollen parent. Find out what combinations work!

Thank you, Ilya. For those who do not want to read too much, just look for the headline "Origins of C. ichangensis and other acid citrus varieties" in the article. Interesting also what it states about Ichang Lemon.

If someone wants to create new hybrids the exact genetic relationships of different species can often be ignored when you just look at the results of antient hybridization events and take them as they are. I think, however, that such a practical and somewhat superficial approach should keep us away from too much speculation. The motto "just try!" is good, often perhaps the only think we can do. But we should then not be disappointed when we don't get what we wanted if our plans and wishes were based on wrong assumptions about the nature of the parent species we used.

I got N1triVoss four or five years ago as budwood, grafted a bud onto a very tiny Poncirus seedling and have now a still small but well growing bush. Leaves were always monofoliate. But this year, some trifoliate leaves appeared. Here some pictures.
First nomal monofoliate leaves:


At the end of the twig trifoliate leaves:

Frying?? Kucle - Pom frites?

I forgot another picture of some Kucle seedlings without Poncirus influence:



Sorry for the pure picture quality. But you see that one seedling has leaves like willow leaf mandarine, one has winged petioles (a Yuzu hybrid?), one has very big leaves for its size (a Pummelo hybrid?) and some - not so clearly visible on the photo - look much like kumquats.

By the way, I reported about a mainly monofoliate seedling with initially trifoliate leaves. This seedling never produced trifoliate leaves again and its leaves contain no Poncirus taste whatsoever. Strangly enough, one of the seedlings from the photo above got one bifoliate leave but was otherwise monofoliate. I can only speculate why this is so. Regarding the monofoliate seedling with initially trifoliate leaves, I had the idea it might be triploid (2x Kucle + 1x Poncirus).

I just want to give you a small update of my plant. Here a new Photo. Very good growth in my glashouse. My Calamondin x Poncirus grew slowly but constantly, so almost without the typical growth-flushes. And a curiosity is also that it branches on immature soft wood. Despite its seemingly slow growth it grew several times larger than it was at the begining of the year, just because it was constantly growing.
Here a photo:



The leaves have a moderate Poncirus taste combined with strong mandarine taste. Bitterness is not very strong.

@Ursirius
Thank you for your friendly answer! I`ll try to be less absent in the future. When your email adress has not changed I can keep up our contact via email.

Regarding your clone of HRS899, I was positively surprised that you did not find its fruits resinious. I remember that the fruit you sent me (the ebay-fruit) was similar resinous as I knew it from Poncirus. But I also remember a nice Citrus smell and a little bit mandarine taste with some sweetness besides relatively weak Poncirus smell and taste. Now, my fruit had already dried out a bit and it was as you wrote the first fruit ever. Did you observe that fruit quality improved over the years?

Perhaps an encouragement for breeding: All seedlings from your fruit were different and all seeds were monoembryonic. Some seeds were defective as we know it from other plant hybrids. But a fair emount was well developed. Those germinated well.

Hello,

I had to prune my Changsha Citrandarin - tragically enough. There was critical bark die back due to a wound infected by mould during our wet winter. So I had to cut off one of its two biggest branches, about 80 cm long and very well branched. Now I have this otherwise very strong branch and can send it whole or in parts to those who would like to have budwood or cuttings.

I have the plant from www.pflanzen-des-Suedens.de (Mr. Meeder, Germany). It is still listed there (https://www.pflanzen-des-suedens.de/Citruspflanzen/In-Vorbereitung/; No. 9). I have not yet gotten fruits. So all that I can say is that it is a strong plant on Poncirus rootstock that has thick thorny twigs and thick evergreen leaves.

In case that more than one person is interested I would divide the branch. I live in Germany. So I can ship to countries in the EU, probably to Brittany, Switzerland and all countries that have no importation bann for Citrus plants.

Yours,Till

That is true. There can be hybrids among the monofoliate ones. But it seems to me that this case is very rare with Calamondin, at least if you let it pollinate itself. All seedlings of Calamondin that I had so far looked exactly the same, no variation in leaf form, except for the trifoliate seedlings. I could imagine that Calamondin produces some hybrid seedlings when cross pollinated by other citrus. Given the flower form of Calamondin natural cross pollination is, however, unlikely.

But when you ask yourself what seedling you should keep than you will look for those you want to have. And these are in our case the trifoliate ones, no matter how their fruit quality will be. Since trifoliate leaves are always dominantly inherited you can be sure that all Poncirus hybrids are trifoliate and that only the trifoliate ones are Poncirus hybrids (or Citrange hybrids etc.). Calamondin x Poncirus hybrids are, besides their hardiness, interesting because you can use them as a test to what degree Kumquat genes can suppress the bad taste of Poncirus, I mean the internal oils and the bitter taste. The existing Citrangequats give me some hope that it is possible but I know nothing for sure at the moment. So producing Calamondin x Poncirus hybrids is just an experiment for me. In case that the results are negative (= bad fruit taste) I will still gain the possiblity for further crosses. When the peel of C. X P. hybrids is sweet (seemingly a dominat trait of Kumquat) I could cross them with other Poncirus hybrids and have the hope that I do finally get a Poncirus hybrid with sweet edible peel.

My Yuzu x Poncirus seems to be extremly dormant in winter. It stands in a winter garden for a few weeks now. Calamondin x Poncirus is growing. Kucle x Poncirus starts growing, Swingle 5 Star seedlings, even Eremorange and two Yuzu seedlings, the latter just hesitatingly beginning. But buds of Yuzu x Poncirus have not become bigger. Pure Poncirus has become big buds in a glashouse that is cooler than the winter garden.

I also tasted fruits from different Poncirus trees. The taste and juiciness of the fruits has definitely something to do with the specific clone because tree that stood side by side had different taste. Bitterness was sometimes very pronounced sometimes almost not present. So it is worth checking different trees and seaching for better clones.
Mikkel was so kind and sent me samples of the Poncirus from Ellerhoop. To my taste, it was quite bitter and fruits just average. But harvest and position of the fruits my play a role.
I found one Poncirus type with almost no bitterness and much less repellant taste and smell. I could taste fruits in two subsequent years, grafted twigs to normal Poncirus and could taste my own fruits last year. Taste was always much better than other Poncirus types I know. (I do not know Swamp Lemon and Poncirus+.) Still, I would not call it "lovely" or "inviting". Lemonade, however, is very good (better aroma than orange or lemon lemonade) but only if you let the juice stand in an open glas for one night, so that the sticky oil can be seperated and certain pine flavors disappear.

Aside from fruit taste, I found other differences between Poncirus types. Some tended to bloom several times a year and especially in autumn during warm spells. Other never did that. My favorate finding never breaks dormancy during warm weather in autumn, even not in a green house. But precocious Poncirus frustrated me because it tries to bloom in autumn when weather is warm. But the flower buds are not totally mature at that moment. So I get flowers the wrong time and the flowers are misdeveloped so that I do not even get pollen. I also know a Poncirus in Bonn botanical garden that blooms in autumn and sometimes also in summer. Another Poncirus in Bonn does not do that.

So whoever wants to improve Poncirus by crossbreeding may also look at plant characteristics that influence winter dormancy.

Thank you very much, Ilya11, for your clear comparision of fruits. That gives me a good idea of the differences. And I would say, Poncirus+ must be much better than the best type I found. My type has a normal amount of sticky oil. It tastes less sour than other Poncirus but the difference is not so great. Still sour. Perhaps just a false perception because it has less repellant aromata than other Poncirus types. But the juice is definitely not bitter (to my taste).

Gratulation, Tom! Yes, it will be very interesting, how much variation our seedlings will have.
I have placed mine in the wintergarden now and it starts growing. I want to push it a bit this year that I can better see how it develops.