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Author Topic: Long term cold hardy citrus breeding project  (Read 7442 times)

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #50 on: March 11, 2018, 04:31:57 PM »
I am thinking that all the citrange, citandarin, citquat, etc., should be remade using the better tasting P.t.  Also with the more zygotic P.t., and with precocious P.t.  I know that is a lot of work and will take a lot of space.  But I am retired and I have no desire to sit around waiting to die.  And I thought my origonal plan, which I still plan to do, was pretty ambitious.

Samodelkin

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Re: Long term cold hardy citrus breeding project
« Reply #51 on: March 12, 2018, 05:27:20 PM »
The taste of the fruits of trifoliata strongly depends on climatic conditions. In a favorable year, with abundant rainfall, the resin is almost there. In a dry cool year Poncirus+ = Poncirus

Samodelkin

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Re: Long term cold hardy citrus breeding project
« Reply #52 on: March 12, 2018, 05:36:11 PM »
The taste of the fruit of hybrids Poncirus also influence the level of farming and growing conditions. For example, hybrid Trifeola under favorable conditions, the leaves become solid, if the deterioration of conditions trifoliatum. Trifeola = Poncirus+Mineola, fruit is almost edible

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #53 on: March 13, 2018, 02:01:22 PM »
Thank you for the information.  "almost edible" is not my goal, but it is a step along the way.

SoCal2warm

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Re: Long term cold hardy citrus breeding project
« Reply #54 on: March 13, 2018, 09:01:08 PM »
The plants will grow much better inside if surrounded by some sort of an enclosure to hold in the humidity and keep the surrounding air from getting dried out.

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #55 on: March 14, 2018, 12:37:42 PM »
Ilya.  How many of the citrumelo 5* x  Flying Dragon hybrid seedlings do you have?  I ask because I plan backcrosses of various 3/4 P.t. 1/4 citrus, and I'd like to know how much segregation for cold tolerance there is in the backcross 1 generation.  I will be following your results with great interest.

Ilya11

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Re: Long term cold hardy citrus breeding project
« Reply #56 on: March 14, 2018, 01:20:03 PM »
Ilya.  How many of the citrumelo 5* x  Flying Dragon hybrid seedlings do you have?  I ask because I plan backcrosses of various 3/4 P.t. 1/4 citrus, and I'd like to know how much segregation for cold tolerance there is in the backcross 1 generation.  I will be following your results with great interest.
Last spring I pollinated with FD 20 castrated flowers of 5*, got 6 fruits in autumn, totally with 45 seeds.
It gave 43 seedlings; 12 of them are clear hybrids.
Best regards,
                       Ilya

Zitrusgaertner

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Re: Long term cold hardy citrus breeding project
« Reply #57 on: March 14, 2018, 04:28:25 PM »
Ilya, are there any crosses with swamp lemon? Is there a chance to get rid of bitterness and resin in F1-hybrids? And: do swamp lemon flowers smell?

Best Regards
Robert

Ilya11

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Re: Long term cold hardy citrus breeding project
« Reply #58 on: March 14, 2018, 05:17:45 PM »
Robert,
Swamp Lemon flowers have no smell, I have not yet seen the flowers of Poncirus+ clone, hope it will flower this spring.
Hope that the absence of oils is a simple hereditary trait that will be transmitted in crosses.
Best regards,
                       Ilya

Zitrusgaertner

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Re: Long term cold hardy citrus breeding project
« Reply #59 on: March 16, 2018, 09:26:42 AM »
Ilya, are the genes identified that cause bitterness and resin in normal poncirus? If not, would it be possibel to find out if you compared the genome of normal poncirus and swamp lemon? Or do I think too simple? Do you plan to make crosses with swamp lemon?
Questions over questions -sorry. Maybe I am a little too enthusiastic about the possibilities.  ;)

Best Regards

Ilya11

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Re: Long term cold hardy citrus breeding project
« Reply #60 on: March 16, 2018, 10:48:44 AM »
Robert,
I am not aware of any mapping of internal oil trait in poncirus. Certainly, it is not a priority for citrus biology projects both in academia and industry. On the contrary, the genetics of bitterness due to the presence of modified flavonones naringins and neohesperidins is quite well studied in citruses.
One can map the genes responsible for fruit oils by genotyping  the segregating population of normal PTxSwampLemon cross, a comparison between the two parent plants is not sufficient, there will be too many differences that have nothing to do with this trait.
I have plans to cross Poncirus+ that is apparently monoebryonic to SwampLemon  to see if the fruit quality can   be further improved.   
Best regards,
                       Ilya

SoCal2warm

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Re: Long term cold hardy citrus breeding project
« Reply #61 on: March 20, 2018, 11:59:42 PM »
Something that I think worthwhile would be to try crossing Dunstan citrumelo with C. ichangensis. Might be hardy to zone 7, in a sunny warm spot.

More long-term, maybe a citrumelo cross with Satsuma mandarin, before being crossed with C. ichangensis.
The first cross is going to be more difficult because 90% of the offspring will grow true to seed.

 (it's a similar zygotic to nucellar ratio for both Satsuma mandarin and Swingle citrumelo, whichever is used as the fruit parent, I just looked it up)

The Swamp Lemon, it sounds like Trifoliate (which has become naturalized and been observed growing wild in some of those areas) might have hybridized with something else. Over a few generations, being spread by birds, the less bitter offspring could have been naturally selected for. Or might even be the zygotic progeny of Swingle citrumelo rootstock. Maybe someone long ago tried planting a grapefruit tree out there and it died down to its rootstock over the Winter, then later fruited and the seeds got thrown into the ground and sprouted. Long ago the first grapefruits were rather small and grew in clusters on the branch like grapes, so it might have simply just reverted back to a smaller fruit size. That's what one would expect if they were propagating out in the wild.
« Last Edit: March 21, 2018, 12:43:54 AM by SoCal2warm »

Ilya11

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Re: Long term cold hardy citrus breeding project
« Reply #62 on: March 21, 2018, 05:06:13 AM »
I do have many hybrid seedlings of crosses between citrumelo ( 5*) with Miyagawa and two different clones of ichangensis.
Best regards,
                       Ilya

ethane

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Re: Long term cold hardy citrus breeding project
« Reply #63 on: April 09, 2018, 04:24:14 PM »
Hi Walt and everyone,
I would love to be able to help on this project, as I have some experience with breeding citrus. My PhD dissertation was on breeding pummelo (Citrus maxima), but I also worked breeding other Citrus. I made a ton of hybrids with Australian Citrus species, which are under evaluation currently at University of Florida. I also made a few hybrids between C. ichangensis and Poncirus trifoliata, which are also at University of Florida. Essentially, all the cool stuff I made are still at University of Florida. Breeding for cold tolerance was not high on our list, as Florida tends to stay pretty warm, and often some tolerance from the rootstock was enough for the tree to survive the occasional cold periods.
It's difficult select purely for cold tolerance, as different factors can affect the tolerance of a particular plant, but recurrent selection using Poncirus with near edible fruit sounds like a good start. I have a some seeds I just started that came from a tree that was 1/4 Poncirus (probably, it makes large, mostly edible fruit and has trifoliate leaves), which I will gladly share material of when I have some to share (legally, of course).
I would also put precocity high on the list; there are some good sources that I would start with. I heard mention of a precocious Poncirus, which is great, but also I would recommend finger limes or desert limes as I know those often flower in a year from seed. So does Fortunella polyandra, but it's fruits aren't so great. Citrus wakonai would also be good if we could get our hands on it.

Below is a picture of a Citrus (Microcitrus) australasica x Poncirus trifoliata hybrid I made at University of Florida.


Cheers,
Dr. Ethan Nielsen

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #64 on: April 09, 2018, 05:04:24 PM »
Welcome Ethane.
I'm in the process of re-writing my goal and method because of the responses I got here.  I now have much higher expectations.
I'm now wanting to combine low poncirin and precocious with high percent  monozygotic seeds.
In the meantime, producing 3/4 P. trifoliata 1/4 citrus seedlings to see how much segregation there is for cold tolerance.  Of course that means finding a replicatible way to measure cold tolerance.
We are both in zone 6.  That doesn't mean what works for one of us will necessarily work for the other.  There are so many other factors not covered by a single number.  But more people working on this can only improve our chances.
Walt
« Last Edit: April 09, 2018, 05:10:01 PM by Walt »

SoCal2warm

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Re: Long term cold hardy citrus breeding project
« Reply #65 on: April 09, 2018, 10:33:51 PM »
For zone 6 I'm thinking you are probably going to have to think about combining multiple strategies, not just hybridization, if you want something very edible.
You might, for example, be able to breed something that can survive outside in a warm spot, up against a south facing wall, near water and large rocks to help reflect/absorb/retain heat, sheltered from wind, etc. (basically going out of your way to create a warm microclimate) and possibly covered with insulation during the Winter on top of that. It is possible, but I don't think it's going to be so simple.

One advantage, in Kansas you have clear skies so that means availability of direct sunlight throughout the Winter. That makes it easy to manipulate this sunlight through the use of microclimate techniques to warm the surroundings.

Normal citrus wouldn't be able to survive in this situation, but much more cold hardy varieties may.

mikkel

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Re: Long term cold hardy citrus breeding project
« Reply #66 on: April 10, 2018, 02:02:28 AM »

I would love to be able to help on this project,
That is great! Welcome! I just have some questions I can`t wait to ask :)
I also made a few hybrids between C. ichangensis and Poncirus trifoliata,

Could you report more about these hybrids? Are fruits more likely to be edible than other Poncirus hybrids?
 
I would also put precocity high on the list; there are some good sources that I would start with. I heard mention of a precocious Poncirus, which is great, but also I would recommend finger limes or desert limes as I know those often flower in a year from seed.

I just have different types of "Microcitrus" seedlings in my greenhouse to find out how precocious they are. Do you know if this trait is herited to further generations?
Below is a picture of a Citrus (Microcitrus) australasica x Poncirus trifoliata hybrid I made at University of Florida.

Have you seen fruits of such hybrids in your work? Are they in tendency inedible like the most of Poncirus hybrids?




SoCal2warm

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Re: Long term cold hardy citrus breeding project
« Reply #67 on: April 10, 2018, 03:23:51 AM »

(Dunstan citrumelo x Satsuma mandarin) x (Ichang papeda x Satsuma mandarin)

(trifoliate x Satsuma mandarin) x Orange Frost mandarin

(trifoliate x Bloomsweet) x ((yuzu x tangelo) x Changsha mandarin)

((trifoliate x mandarin) x Orange Frost mandarin) x ((trifoliate x pomelo) x Ichang lemon)



ethane

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Re: Long term cold hardy citrus breeding project
« Reply #68 on: April 11, 2018, 06:58:39 PM »
Hi Mikkel,
A lot of my hybrids were small plants when I left, so I can't report on their edibility. I do know the particular strain of C. ichangensis I had was not very edible. I'm sure there are better, more edible examples of the species. So the hybrids I made between C. ichangensis and P. trifoliata will likely be evaluated as rootstocks.
Precocity in Microcitrus hybrids seems to be easily passed on. I made some triploid hybrids that were 1/3 finger lime and 2/3 lime or lemon, that flowered after a year. This was surprising, given that finger lime was in the genetic minority. One I sampled I know was self fruitful in the greenhouse and was seedless, which we were aiming for, but the resiny finger lime flavor was also dominant (We also had limited genetics available for finger limes, as most I used were seedlings from California, and there are probably better tasting selections. I know more are in the process of being imported from Australia. It's a long process of importing and cleaning up for budwood release.) I've grown other seedlings that also flowered when a year old. Finger limes also tend to flower multiple times in the year, not just in spring.
The Microcitrus x Poncirus hybrids were also small when I left, which I made last year, so I can't comment on precocity or fruit quality.
Here's an illustration of Microcitrus hybrids I made from my dissertation: EXPLOITATION OF PUMMELO (CITRUS MAXIMA (BURM.) MERRILL) THROUGH BREEDING, PLOIDY MANIPULATION, AND INTERSTOCKS FOR IMPROVEMENT OF CULTIVATED CITRUS; Ethan Nielsen, University of Florida, December 2017.



Walt

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Re: Long term cold hardy citrus breeding project
« Reply #69 on: April 13, 2018, 03:54:58 PM »
At the start of this thread, I said I was using mandarine, orange, and P. trifoliata. 
Mandarin because it is my favorite citrus, it is often zygotic, and it is moderately precocious.
Orange because I had access to OP Sanford seeds, and oranges are much like mandarins.
Trifoliate orange, obviously, because it is winter-hardy in zone 5.  It has no other excuse for being in my garden.

Now, in addition, I plan to start another group using finger lime and precocious P. trifoliata.  The F1 should be somewhat precocious because of the finger lime.  The precocious P. trifoliata is recessive by many reports.  The backcross of (fingerlime x P. trifoliata) to precocious P. trifoliata, I hope will segregate for precocity.  Also it will be segregating for winter-hardiness and traits that go together to give winter hardiness, i.e. dormancy that lasts all winter, low temperature tolerance.

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #70 on: April 25, 2018, 12:35:11 PM »
Last year I succeeded in getting citrumelo 5* x  Flying Dragon hybrid seedlings, but it was after several years of failures.

From reading your posts for several years, I'm sure you know what you are doing and how to do it.  So it sounds to me that maybe Ponciris-Citrus hybrids aren't very fertile.  Is that generally true?  Have people tried enough crosses using Ponciris-Citrus hybrids as parents to know how fertile they are?  I have read of the kumquat x citrange hybrids of course.  And Dr. Brown's hybrids.  Those made me think it was easy, but for all I know they resulted from thousands of attempts.

Ilya11

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Re: Long term cold hardy citrus breeding project
« Reply #71 on: April 25, 2018, 01:46:19 PM »
Walt,
I guess you are right, hybrids  with poncirus and fortunella are more difficult to obtain than crosses between classic citruses.
The first barrier is the time of flowering: early for poncirus or late for kumquats. This of course can be overcome by pollen storage.
I also observed the influence of climatic conditions, with hot weather during flowering favoring  fecundation. I am doing hybridization under open ground conditions, most likely doing it in protected environment would help.
On a top of this, I believe that due to evolution distance these hybrids are more difficult to obtain. I read an article showing a high frequency of aneuploids ( chromosome number  abnormalities) in hybrids between Fortunella and citruses.
Use the bridging varieties like hybrid kumquats, citranges or citrumelos  could be a way to overcome this type of incompatibility. I found that Kucle kumquat hybrid is very easily pollinated by 5* citrumelo to produce interesting zygotic seedlings.       
Best regards,
                       Ilya

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #72 on: July 11, 2018, 02:46:15 PM »
How tall do P. trifoliata have to be to flower.  I'm asking about both precocious and regular.

Ilya11

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Re: Long term cold hardy citrus breeding project
« Reply #73 on: July 11, 2018, 04:19:42 PM »
Precocious one starts to flower when about 20 cm tall, but fruiting is delayed, most fruits appear in 3 years, many early flowers are incomplete. At this age the second flowering in summer is giving some fruits, but they do not have a time to mature in the open ground.
Best regards,
                       Ilya

Walt

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Re: Long term cold hardy citrus breeding project
« Reply #74 on: July 12, 2018, 02:39:58 PM »
Thank you for the information. 
Am I right in assuming that a scion from a plant that has bloomed, grafted onto a meter tall P.t. seedling, will bloom within a year or two? 

 

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