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Messages - mikkel

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1
Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« on: June 03, 2021, 06:45:14 PM »
Thanks for the link!
Nice to see that his research has fruited.
I did a bypass graft with 5Star on a Poncirus rootstock this spring the first flush is already as twice as strong as in the last years I will try that on other plants it might give immature plants also a push.

2
Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« on: June 03, 2021, 05:36:44 PM »
@kumin What is Bishop Citrandarin? is it from Alan Bishop?

3
Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« on: June 03, 2021, 04:27:25 PM »
@Walt, yes plans are plans and only what flowers flowers... that's the hard truth :)
I found many zygotic seedlings among the 5Star and N1tri seedlings I got as a from @Ilya. Even some monofoliate ones among the 5Stars.
These are good varieties for breeding.

4
Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« on: June 03, 2021, 05:11:51 AM »
Mikkel, perhaps you are referring to outcrossing vs backcrossing within the original parents (sweet orange and Poncirus). Backcrossing should narrow the results more than outcrossing would.
The main reason I want to use the segentranges is that they've gone through a very vigorous screening for cold hardiness. The reason I want to use segentrandarins as breeding partners is potential shorter generational cycles, cold hardiness, lower off flavors, and potential earlier ripening of fruit.

In hindsight I suspect US 852 would have been a good seed source. There are a number of tri-specific cold hardy hybrids. These appear to be vigorous in many cases (Thomasville).


                           
I was thinking more of the dichotomy of hybridisations between different citrus species (species hopping), such as Pt x Orange ---> F1 x mandarin --->F2 x pomelo ---> F3 x kumquat ---> and so on
in contrast to backcrossing, where the hybridisations are limited to one parental species.

In theory, I imagine a crossing plan as follows:

F1 cross C35 (Pt x orange)

x selfing

---> F2
mass selection (like you did with the C35 seedlings)

backcross of the hardiest with Citrus

---> F3 
then: mass selection for desired traits

backcross to the same crossing partner like in F2

and so on.

Apart from the time it takes...

I would guess that by concentrating on a few traits and limiting it to one backcross partner, the variance of the offspring can be better limited within the desired traits.

The hybridisation of new Citrus species is also promising, but has the disadvantage that the number of seedlings must be larger, because the combination possibilities are simply more divers and there may be undesirable gene combinations that lead to completely different traits than in the parent species. Ilya once gave an example of sweetness, which is encoded by different genes in 2 citrus species, but the combination of both leads to sour hybrids (I hope I remember the example correctly).

Both has its reason and depends on what is to be achieved. I will do both as there are so many other factors that are involved (e.g. no flowers on a certain plant and the year is lost and so on)
but for a designed breeding program I would prefer a backcrossing scheme.

Wild hybridisation is good to find new types and new combinations.

5
Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« on: June 01, 2021, 06:56:46 PM »
I use "wild crossing" only in the absence of a good English term for the opposite method of species-restricted crossings as practised in backcrossing. I don't prefer one over the other, I just feel that it is more predictable what to expect from these backcrossings (as you stay within the given genpool). I am interested in any strategy and the reasoning behind it.

6
Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« on: June 01, 2021, 05:31:02 PM »
Do you see a technical advantage in "wild" crossing? Or is it just your choice?
I do both or better I will do backcrossing in the future :) . But I see more advantages (apart from the long waiting time) in backcrossing, because it is probably easier to plan.

7
Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« on: May 29, 2021, 06:50:16 PM »
btw have you read about grafting on Limonia spec. (not C.limonia but Limonia the genus)? It's just something I read, but they say that grafts on Limonia flower very soon after grafting, almost immediately. But I am not sure if this also happens with immature grafts.

8
Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« on: May 29, 2021, 06:29:51 PM »
I thought if you already have a F2 (your C35 seedlings) with almost the hardiness of Poncirus, it would be a good idea to cross it with the original Citrus parent of C35. As you have an almost hardy hybrid, but with still inedible fruits, you have already achieved 1 goal. A backcross with Citrus could bring the focus to edible fruits.
If a plant had edible fruits it would make sense to cross it with Poncirus or with C35.
According to the ideal backcrossing scheme
A x B -> F1 
F1 x F1 -> F2S1
F2S1 x A / B -> F3BC1

9
Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« on: May 29, 2021, 04:49:19 PM »
Like always,  one gardener but a hundred planners :) Sorry for being one of those planners...


10
Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« on: May 28, 2021, 04:06:53 AM »
Fingers crossed that there are already some plants with edible fruit! Just from theory. I would guess that a backcross with Citrus is is a good option with these F2 survivors.

11
Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« on: May 25, 2021, 05:38:52 PM »
For me TaiTri seedlings were more hardy than some 5Star seedlings this winter. Both were under a snow cover.

12
I could not find any citations on this hybrid. Could you post a link to more information?

While searching, I stumbled across this interesting list. Probably all these hybrids are history now.

https://conservancy.umn.edu/bitstream/handle/11299/140015/TB252.pdf?sequence=1&isAllowed=y

13
Cold Hardy Citrus / Re: Yuzu Ichang Papeda cross
« on: May 10, 2021, 04:51:51 PM »
@Zitrusgaertner Bernhard Voss has an Ichang Papeda at a similiar size of yours. And hardy since years.
Where did you get your plant from?

14
Cold Hardy Citrus / Re: Is precociousness inherited?
« on: March 09, 2021, 04:34:10 PM »
Red Dwarf, a precocious FD

15
Cold Hardy Citrus / Re: Is precociousness inherited?
« on: March 09, 2021, 09:16:59 AM »
I won`t suspect F1 hybrids with the precocious Poncirus to be precocious as well. But it might be an option to backcross the F1 with prec.Pt or another precocious variety.

Concerning C.wakonai I was reported:
Our recent results here suggest that the early-flowering trait is quickly lost during a backcrossing program (backcrossing to C.reticulata), even when we try to apply high selection pressure for early-flowering.  So I suspect there are recessive allelels involved in early-flowering and it will be necessary to ensure both parents have an early-flowering parent in their pedigree.

It might be similiar with precPt.

I was wondering about if it is an option to to create an edible precocious Citrus first and cross it with precPt or Red Dwarf from Jiri. If genes for precociousness are the same in both parents it might give a chance to find a homozygous hybrid.

16
Citrus General Discussion / Re: monoembryony inheritance question
« on: February 15, 2021, 02:27:12 AM »
Some Ichang Papedas seedlings and hybrids have even a shorter juvenile stage. I found seedligs of Lime Ichang, Citron Ichang, N1tri flowering within the first year. But only once. It is not stable. But some reached full maturity at the age of 4.
Bernhard Voss told me that he selected all his Ichang Papeda hybrids by early flowering. He said it happens quite often.
It is definately a path I will follow.
Lets hope this winter hasn`t killed them....

17
Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« on: February 13, 2021, 08:16:10 AM »
I don't think backcrossing would lead to lower winter hardiness in every case, certainly in most cases, but in exceptions there might be a chance. Hardiness is not only controlled by one gene, but backcrossing could also work with several genes. It just has lower chances... but it has higher chances of sorting out the right genes than mixing them with other sources.... at least in theory...
In practice I would go both directions...


18
Citrus General Discussion / Re: monoembryony inheritance question
« on: February 12, 2021, 05:00:27 PM »
Most of the hybrids I have made have been with Ichang Papeda. Either as mother or as pollen donor. I have not found any polyembryonic seeds. I suspect that Ichang papeda has some ability to produce zygotic seeds.
But of course it is possible that I have only used zygotic mother plants by chance.

19
Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« on: February 12, 2021, 04:48:45 PM »
   At this point...

just ideas:
It would be interesting to backcross it to the orange parent,  maybe as a side project beside your plans.
You could take HRS899A into your consideration too. It is an F2 Changsha x P.t. hybrid quite hardy and has good fruits as far as I heard about.

20
Thanks Ilya!
So if I understand it right even the roots were frozen at -9°C? That is even more encouraging.

21
Citrus General Discussion / Re: US145
« on: December 30, 2020, 02:32:48 PM »
this means that US145 backcrossed with Thong Dee produced higher rates of seedlings with edibility and cold hardiness (combined in the same seedling) than backcrosses of other Poncirus hybrids.

22
Actually I have already done this cross. It produced more than 200 hybrid seedlings that in spring were exposed to artifical freezing at -9C for 2 hours. Two dozens survived, three had no damage at all.
[/quote

Did you kinda prepare the seedlings before the freeze? Like slowly cooling down?
Did you freeze the whole plant with roots?
Thank you!

23
My impression is that it is even more important to produce a large quantity of hybrid seedlings than the parent combination.
Regardless of which combination one choose, it might be a good strategy to backcross hybrids. e.g. a hybrid with good fruit quality but low frost tolerance with the hardy parent and a hardy but non-edible hybrid with the citrus parent. But one must always produce a lot of seedlings and select the best ones. Anything else would be a stroke of luck.
From the point of view of backcrossing, citrumelos would be best crossed with pomelos.

Everything else will work too, but if one want to cross in a certain trait, backcrossing is a way to plan.
However, onecan also just get lucky and find the desired traits in a random cross.
a contra is that pumelos take a very long time until maturity... so backcrossing is very long term strategy. So random crosses and large numbers of seedlings might be a better option in this case... when you consider your time...
But in any case, the chances increase the more seedlings are produced.

long talk short sense Bloomsweet x Citrumelo sounds good.

24
Cold Hardy Citrus / Re: HRS 899 experiences ?
« on: December 21, 2020, 04:12:19 PM »
Robert, (zitrusgärtner) has a fruiting 899A.

25
Citrus Buy, Sell, & Trade / Re: Red fingerlime seeds
« on: December 18, 2020, 04:13:39 AM »
I just wonder about the precociousness of (formerly) Microcitrus. Some say it takes very long until the first flower, but e.g. Ethan Nielsen, which worked professionally with it said it is sometimes flowering in it 1st year.

http://tropicalfruitforum.com/index.php?PHPSESSID=8c123c86f04422c706d2ba0f384c7879&topic=26278.msg316675#msg316675

Any experiences?

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