Kumquat x Poncirus

[Marcin]

Hi. I'd like to share my experiences on crossing kumquat with trifoliate orange.

I've heard many times that it's a really difficult cross to make, but I still wanted to try. So last year I've been making some pollinations.

Nagami kumquat x Flying dragon Poncirus
I used two different Nagami cultivars as the mother plants. Pollinated flowers set fruit easily, and seed set proved not bad. The seedlings germinated quickly, but soon some of them refused growing. Still, the rest is growing fine up till now and I hope they will stay like that.


For comparison - standard Poncirus seedling on the left, Nagami x Poncirus on the right:


Reale mandarinquat x Flying dragon Poncirus
In this cross, fruit and seed set were also not bad, but most of the seedlings proved weak and generally aberrant. Some had strange, narrow leaves, and some were even monofoliate. Maybe these abnormalities are connected with the fact that Reale is triploid. Still, I think that with a bit of luck this cross is worth a try.


So to sum up, I think that crossing kumquat with the trifoliate orange is not such a bad idea. There's a good chance of getting a really cold hardy citrus with quite edible fruits.

What do you think? Have you tried making similar crosses? If yes, have you met any obstacles?

[Florian]

I have never tried this cross but I will follow your work with great interest! Thanks for sharing.

[mikkel]

Thanks for your report! Very interesting.
Could you please explain the other pictures on your photo account. There are many interesting pictures.

[hardyvermont]

It is good to hear that you have made these crosses successfully.  I crossed Meiwa with Poncirus without fruit set.  Meiwa has hundreds of tiny flowers, almost all of them never set fruit even under normal circumstances. 

[SoCal2warm]

You might get something even cold hardier on the second cross, that is, if you try to grow a seedling of the poncirus x kumquat hybrid. That would be due to possibility of recessive genes or weeding out a dominant gene that may be detrimental.
Unfortunately I would expect a poncirus x kumquat hybrid to be highly nucellar. You'd have to go through a lot of seeds to find a zygotic one, if there were any.

I've heard that kumquat x Satsuma can be pretty cold hardy, down 14 degrees F.

Kumquat is usually always zygotic, so you could always perform a second generation cross by using it as the fruit parent.
That is kumquat x (kumquat x poncirus)

[Ilya11]

Very interesting Marcin, please keep us updated on the growth of these seedlings.
Do you remember what was the embryo color of hybrid seeds- green or white?
Have you castrated the Nagami flowers? I noticed that when it is flowering alone there are virtually no seeds formed. That is why this summer I pollinated non-castrated Nagami with Swamp Lemon, we shall see if there will be some hybrids.

[Citradia]

Maybe it will be similar to a citrangequat but with more poncyrus traits. 

[Marcin]

Thanks for all your answers.

Mikkel, I've added descriptions to the photos.

Hardyvermont, this could also mean cross incompatibility. I'll try to check that when my Meiwa flowers. Thanks for sharing your observation.

Ilya11, I think the seeds looked more white than typical kumquat seeds, but I haven't removed the seed coats so can't be sure. Yes, I have castrated the flowers.
Nagami - Swamp lemon hybrid sounds good! I hope the cross will succeed.

[Ilya11]

Thank you

[Marcin]

Nagami x Poncirus seedlings are changing colors.

[SoCal2warm]

Thank you for keeping us updated

Your work is very interesting.

[mikkel]

thanks for posting!
Do you still have the Reale mandarinquat x Flying dragon Poncirus habrids?

[Marcin]

Mikkel, unfortunately they were weak and died. It's very rare to get a healthy seedling from Reale.

[Walt]

I'm always glad to learn about someone growing Poncirus hybrids.  Please do keep us informed of results.

[tedburn]

Hello Marcin,
interessting cross.
Which temperatures in this winter did your
Kumquat x Poncirus take ?
Best regards Frank

[Marcin]

Frank, sorry for delayed reply. Last winter these hybrids were exposed to only slight frost, like -5 or -6 C, of course with no damage but that doesn't say much. This year I planted them inground, so the winter will be a real test for them.
They have an interesting trait in that the leaves change colors, but not all drop immediately. Some of them can last on the plant through the winter and become mostly green again. The leaves were already reddish in October, and many still hang on the plants now in the beginning of December and keep the color.

End of October:



Yesterday:

[tedburn]

Thank you Marcin, very interesting plant and nice pictures with the reddisch leaves.
Curious how it develops in ground - good succes and regards Frank

[Till]

Thank you, Marcin for the nice pictures. That is interesting how the plants are half way between decidious and evergreen.
I have a Sanford Segentrange (noname) that gets slitely yellow leaves in autumn that are kept throughout winter and are dropped the following spring when new leaves develop. Its behaviour is somewhat similar to that of your hybrids.

Some of my Kucle (= Clementine x Fortunella) x Poncirus hybrids get yellow leaves, too, but not so constistently as yours.

[vnomonee]

Very nice, did you graft or root incase your original plant dies?

[kumin]

Excellent photos, Marcin. Your plants show both very good lighting and nutritional conditions. Finding a percentage of seedlings to be weak and unthrifty is to be expected in distant Citrus crosses, especially in F2 hybrids. Your citrumquats should carry the genetics needed for selecting even hardier F2 and F3 progeny within mass populations, especially after zygotic seed parents have been identified and utilized.

Nucellar parents can obviously serve as pollen parents, but zygotic x zygotic crosses are preferable in my opinion, as the subsequent progeny is probable to also be highly to completely zygotic.

[pagnr]

The red foliage phase is rather nice.

[Jibro]

The nice red color is inherited from Flying Dragon, normal Trifoliate and its hybrids have only yellow-orange autumn color.
I live in a similar climate and I think our winters are too much for F1 Poncirus hybrids. Marcin, I would suggest taking some cuttings a storing them in a refrigerator for grafting, if you do not have backup grafted plants already...one night with -18°C or - 20°C will most likely destroy them completely...

[pagnr]

The nice red color is inherited from Flying Dragon, normal Trifoliate and its hybrids have only yellow-orange autumn color.

Rootstock seedlings of the same strain of normal trifoliata are fairly variable as to autumn colour, and to some level when they change colour and how long they hold autumn colour. Weak seedlings, off types and runts can be clearly different in their colour and timing of change.
There are some oranges and reds possible, even verging on maroon.
Stressed or neglected trees, underfertilized etc can also turn colour earlier.

[Marcin]

Thank you all for the replies.
Till, it will be interesting to track your progress with Kucle x Poncirus hybrids.
Vnomonee, Jibro, I'm prepared that they can be harmed or killed by more severe frost. I've made backup copies of the three most promising plants.
Kumin, I find your breeding work really impressive. Maybe when I obtain fruits from these citrumquats, I'll manage to make a selection project similar to yours, although on a much smaller scale.

[Till]

Marcin, I will keep you updated with my Kucle x Poncirus. I have not much new information at the moment. Growth was not very good this year. Earth problems. The earth in which they prospered last year had seemingly changed its chemistry this year. I grafted some seedlings on older plants in order to fasten up blooming and planted most seedings in ground. (I have kept the garden soil in my winter garden, so that it is a real garden.) They should grow much better the next year.