Interesting cold hardy monofoliate citrus/poncirus hybrid.
Two springs ago I pollenated my 'Temple' orange with poncirus 'Flying Dragon' pollen of which 15 fruits were produced. These 15 fruits all made seeds sprouting hybrid seedlings which amounted to around 250.
My report today is about one of two unusual monofoliate yet truely hybrid seedlings. Both monofoliate hybrid seedlings came from the same fruit which is interesting in itself.
Both monofoliate seedlings were grown to 5 gallon size in the greenhouse and planted last summer, in pot, in the open field, exposed to all winter weather. Early December gave these two plants a early and harsh cold hardiness test with two nights of lower single digits and several daytime highs of upper teens to lower 20's. New Year's day I removed the monofoliate hybrids from their outdoor setting and place inside the warm greenhouse for a early spring.
One monofoliate seedling froze to near ground level but the other survived in fair shape. The monofoliate survivor did not go untouched but in my opinion showed good potential hardiness with only 30% younger stem damage in the upper canopy. What is so great about it's winter hardiness is the lower trunk did not have any air/soil transition zone damage. I have found those lower trunk freeze cracks the most deadly to hybrid citrus. December's frigid cold is the worst for those air/soil transition zone freeze cracks because the still warm soil seem's to keep sap flowing near ground level.
This now cold proven and worthy of further development hybrid has very sweet smelling leaves that are often monofoliate but sometimes will produce a trifoliate. Often a monofoliate leaf will have almost no petiole but the few trifoliate leaves will always have a regular petiole. The monofoliate leaves seem to have a very rough texture and sawtooth margin where the few trifoliate leaves will be smoother in texture and margin. The monofoliate hybrid's growth form is more branched than typical and rate of growth slightly slower than typical, yet robust. I hope the early branching growth form will mature into a fruiting stage faster than normal so I can get that all important taste test. I'll be budding some juvenile wood from 'monofoliate' within the upper canopy of a fruiting citrumelo, trying to forced mono into maturing.
That's all for now and here are some pics of the new growth. A very interesting atypical hybrid since it has cold hardiness.
Notice the Red Mite. My worse citrus pest.
Thanks for that fascinating report, Don.
I don't recall seeing any citrus with such consistently serrated leaves. There doesn't seem to be any of the contorted Flying Dragon features in this hybrid. How about the trifoliate seedlings. Any twisted stems and thorns?
I'm always amazed by the rate of growth of your seedlings in USA. Here in the UK climate 2 year old seedlings are never so big.
Keep us posted on developments.
I think it is wonderful that people are again trying what Swingle did a hundred years ago. There is so much more potential. I was going to try a similar cross in a year or two (need to get a fruiting 'Temple' first) using a trifoliate that is supposed not to smell and taste as badly.
Hi Mike,
Since this unusual 50/50 hybrid has some cold hardiness I find it so interesting. The plant look's more like what would be expected in a 75/25 hybrid backcross. I hope the fruit might be more like a true citrus with this hybrid.
In regard of 'Flying Dragon' passing it's genes. Please read this link below.
INHERITANCE OF THE CONTORTED PHENOTYPE IN CITRUS X CV. FLYING DRAGON HYBRIDS
I used 'Temple' as the mother and 'Flying Dragon' was the father and as was stated in the article above. The contorted traits were not passed to those hybrid offspring. Yet, Phil in Texas has a hybrid offspring with 'Flying Dragon' as the mother and the contorted traits were passed. It's very interesting seeing such things first hand.
If you think this seedling was fast growing just wait until I report on the Citrderosa ('Ponderosa' X 'FD'poncirus) hybrid. It fill's a 10 gallon container!
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Hi GoneBananas,
It's fun breeding the hardy citrus and might even be profitable if that magic edible specimen was found. Even without any chance of profit I would still keep working with citrus/poncirus breeding to satisfy my curiosity. One thing for sure, any work with poncirus hybrids is still pioneering even 100 years after Swingle.
Yes, use a 'Temple' for your first hybridization trials. 'Temple' has a good set with poncirus pollen and the fruits are seedy. What's even better about 'Temple' is I have found around 50% of the hybrid offspring are zero degree cold hardy. I found such a high rate of hardy offspring strange since 'Temple' itself is very unhardy. I guess the hardy mandarin genes are in 'Temple' but not current to 'Temple'.
Good luck and update us with your citrus breeding trials.
Very interesting, Keep up the good work and keep us posted.
Pat