First fruits of Citrumelo 5star x Morton cross

[Ilya11]

This year at the end of May the first of the hybrids that I made  in 2011 by pollination of 5* citrumelo flowers by Morton Citrange flowered for the first time:


 
Most of the  flowers were defective without pistils, but eventually three fruits were formed



Fruits began to change color at the end of September, one of them looks ripe now









It is approximately of the size of poncirus fruit, has a pleasant outside odor resembling orange with fruity overtone, albedo is thick with some faint bitter taste, juice is sour like a lemon with no bitterness, no internal oils, no perceptible poncirus aftertaste. By taste it is close  to unripe orange.
I measured a sugar content - it had 13.5° Brix (Spanish clementine in parallel showed only 11°)

This  plant (11_03_24) is very resistant, probably more than both of its parents. It is in open ground without any protection since 2012, never was damaged by snow and freezing temperatures under conditions when both 5* and Morton showed some leaf damage. It requires a lot of iron supplement in  spring  to avoid deficiency, otherwise is very healthy 2 m high bush with small largely monofoliate leaves.
Could be an interesting step toward a  hardy citrus with sweet taste.

[mikkel]

Good work!

[Jloup27]

The plant and the fruit are really beautiful .
It takes another few years to evaluate the full potential of the fruit that looks promising.

[Florian]

Well done, Ilya. It will be interesting to see if the fruit quality changes (improves) over time.

[Citradia]

Lovely. Morton and citrumelos are rather large fruits compared to other citranges. May this combination of the two produce larger fruit in the future?

[Ilya11]

I do not think so, evidently this guy decided to be of the size of its poncirus grandparents.
I still have its 5 brothers that survived out of initial three dozens. 
For me it is like a proof of  the concept, that it is possible to get rid of poncirus taste and to improve the hardiness with the respect of first generation hybrids.
It has also a tremendous advantage to ripen very early.

[Florian]

I will certainly follow this hybrid's development with great interest! Keep us updated.

[Walt]

This is very encouraging.

[kumin]

Excellent combination of hardiness, early ripening, and palatability. The fruit is attractive as a bonus. Have you been able to determine if the seeds are zygotic?

[Ilya11]

Unfortunately they are highly polyembryonic, but pollen is fertile,  I have already several seedlings of its backcross to 5star.

[kumin]

With it's positive attributes, it may prove valuable as a parent. Getting rid of the Poncirus tastes while retaining outstanding cold hardiness in the same plant is a real milestone.

[Mangifera08]

Really cool! Thanks for the information and the pictures.
What exactly is the Citrumelo 5star? (Ponicirus trifoliata x ? )

[kumin]

Ilya11, do you suppose the modest fruit size contributes to the early ripening? My thinking is there may less time lost in expanding fruit size, allowing early maturity. In colder regions, early maturity is of paramount importance, as severe cold temperatures would completely destroy the fruit. The ideal super cold hardy citrus tree needs to retain almost all of the positive characteristics of Poncirus, while discarding the negatives.

Thick albedo in the first crops of new citrus cultivars is not unusual. Although fruit size may remain constant, albedo thickness might decrease.

[Ilya11]

Really cool! Thanks for the information and the pictures.
What exactly is the Citrumelo 5star? (Ponicirus trifoliata x ? )

It is an open pollinated seedling of Swingle citrumelo. It is extremely hardy and although does contain some amount of internal oils, can be used for a  jus or a  curd for the tarts.
http://citrusgrowersstatic.chez.com/web/viewtopiceb1b.php
Not 100% zygotic, but after castration and cross pollination yields a  decent number of zygotic seedlings.

[Ilya11]

Ilya11, do you suppose the modest fruit size contributes to the early ripening? My thinking is there may less time lost in expanding fruit size, allowing early maturity. In colder regions, early maturity is of paramount importance, as severe cold temperatures would completely destroy the fruit. The ideal super cold hardy citrus tree needs to retain almost all of the positive characteristics of Poncirus, while discarding the negatives.

Thick albedo in the first crops of new citrus cultivars is not unusual. Although fruit size may remain constant, albedo thickness might decrease.

It certainly can be like this, but I am trying to prove the opposite by backcrossing it to 5star or even crossing with Sarawak pomelo.

[Mangifera08]

It is an open pollinated seedling of Swingle citrumelo. It is extremely hardy and although does contain some amount of internal oils, can be used for a  jus or a  curd for the tarts.
http://citrusgrowersstatic.chez.com/web/viewtopiceb1b.php
Not 100% zygotic, but after castration and cross pollination yields a  decent number of zygotic seedlings.

Very interesting, thanks. Thank you very much also for this great link!

[tedburn]

Hello Ilya,
very interesting cross, are there some new informations about fruit specifications as taste, size, month of ripening,.. in the last two years 2020 and 2021, would be interesting - thank you.
Regards Frank

[Ilya11]

Last two seasons have not brought any improvements in fruit quality.
Summer of 2020 was very dry  while 2021 was wet and cold and both these conditions resulted in reduction of fruit internal  flesh.

[Grapebush]

This one looks like a nice cross.
Are there any images of the plant and fruits?

[Walt]

Now that US 1279, 1281, and 1282 citandarins, each with >90% zygotic seeds, and 5* and Bishop citrumelos are in hand, I could make crosses like this like an assembly line.  But my plants are still young, so maybe not this year.
So many good crosses to make.  So little time.
Always good to read about your work Ilya.

[Ilya11]

This one looks like a nice cross.
Are there any images of the plant and fruits?

Images are the collateral victims of Russian invasion of Ukraine.
They were stored at radical.ru that is now down.

[mikkel]

Maybe I can help out

[tedburn]

@ Ilya, are there any news from your breeding with 5* backcross or Sarawak  ? Very nice fruits though a little bit small.
@Mikkel , thanks for delivering of deleated pictures