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Messages - Walt

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1
Cold Hardy Citrus / Re: Poncirus hybrid crosses
« on: December 11, 2023, 12:26:00 PM »
Thanks for the information on the Ponciris parents of some of the Ponciris hybrids.  So I can relax even more about inbreeding.
Something I should mention is that since it takes time and effort to make controled pollinations, getting F1 seeds in quantity, hundreds or thousands isn't easy.  But it is ok to grow out the slightly inbred F2 seeds where F1 trees have produced lots of seeds.  It would be good to make controled pollinations every second generation.  If one keeps seedlings from each F1 tree seperate, flowers on each F1 tree could be crossed with an unrelated, or at least noy closely related, tree.Since seedkings take a few years to bloom, some polllinations can be made each year and every year there would several seedlings growing and, at least in my situation, my acre could be kept full all the time.

I said above that new F1 crosses still have their place.  For example if you want to breed hardy kumquats, not much F1 breeding stock is easy to find.  Another such is finger lime which I have mentioned elsewhere that an F1 finger lime x Ponciris+ could be useful in zone 8 or perhaps zone 7 in sheltered spots.
Also I have bought Kishu Seedless for its dominant gene for seedless.  It can be crossed as a pollen parent and half the resulting seedlings will be seedless.  It can pollinate seeded seedlings in a breeding program, and its seedless F1 plants crossed back to your best seeded trees in your breeding population, and repeat again and soon your seedless seedlings will be as good as your seeded trees.  And since in this seedless breeding you are only trying to bring in the one gene, only a small population of the Kishu decendents will be needed.

2
Cold Hardy Citrus / Re: Poncirus hybrid crosses
« on: December 10, 2023, 04:43:51 PM »
This thread brought up inbreeding.  Since then I've done lots of thinking, and more importantly, lots of reading about inbreeding.
Corn breeders in areas where hybrid corn isn't used often use synthetic varieties.  These are varieties that can be re-synthisised if the varieties are lost.  These varieties are created by test-crossing many inbred breeding lines of corn.  Then those lines with the best hybrid seedlings are intercrossed to make the new variety.
The more breeding lines that are put into the synthetic variety, the less inbreeding will take place in future generation.  On the other hand, if they start with the pest line based on the test crosses, each added line will be less good.  Experimental results show that the best number of lines vary between 8 and 12.  After all, if one uses the best 8 best, number 9 will not be as good as the first 8, though the new variety will have less inbreeding.  Somewhere between 8 and 12 the balance between degree of inbreeding and the value of more lines reaches the break even point.
So it would be desirable to start with about 8 citrus clones to not be concerned about inbreeding.
So what to start with? 
Kumin's selections, of course top the list.  But being all seedlings of C-35, They count as a group as more than one but less than 2 I think.  US 852, US 1279, US 1281, and US 1282 are all good to include but 2 of them are P. trifoliata x Changsha and 2 of them are P. trifoliata x Clementine.  I don't know if the same P. trifoliata was used in making those crosses.  But as a group they could count as somewhere between 2 and 4, because I don't know how related they are.
As has been mentioned elsewhere, citromelos should be useful in breeding hardy citrus.  I don't know the pedigrees of any citrmelos so I don't have a good guess at how many to count this group as,
P. trifoliata+ can be used in further breeding and counts as one.
I think Troyer citrangequat has potential and can count as one.
So this list can be used as a guide to estimate the inbreeding in future generation.  I counted 6 or more, probably 8 or more.  It means the germplasm exists for breeding hardy non-inbred citrus  without going back and making new F1 hybrids, which would take more time.  Not that I would discourage from making new F1 hybrids.  They have there place and will be used if someone makes them.

3
Cold Hardy Citrus / Re: Accelerate fruiting process on hybrid seedlings
« on: November 28, 2023, 12:27:51 PM »
Things that accelerate growth accelerate fruiting.  Things that make taller but not more leaf nodes, like low light or giberilic acid, don't count.  What counts is good healthy growth and the number of leaf nodes between the seed and the top of the plant.  That said, grafting onto a good healthy plant could make a seedling grow faster in a healthy way and thus accellerate bloom.

4
Citrus Buy, Sell, & Trade / Fast Flowering Ponciris
« on: November 14, 2023, 02:19:30 PM »
Does anyone have fruit or seedlings from Laaz's fast flowering Ponciris?   Or scions available next spring?

5
Cold Hardy Citrus / Re: Poncirus hybrid crosses
« on: August 28, 2023, 12:44:35 PM »
1rainman.  That is what I thought likely.  Make the cross both directions, if I can.  Then backcross in both directions, if I can, and see what I get.  And go from there.

Mikkel. 

6
Citrus General Discussion / Re: An introduction, of sorts.
« on: August 28, 2023, 12:35:52 PM »
Welcome to our rabbit hole.  It is  a deep one.

7
Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« on: August 23, 2023, 12:31:55 PM »
Every observation is of value.

8
Cold Hardy Citrus / Re: Poncirus hybrid crosses
« on: August 23, 2023, 12:29:31 PM »
Yeah, cold hardy citrus breeding is no walk in the park.

Again, one of the biggest roadblocks is high rates of nucellar seed. What probably needs to happen at some point is someone needs to make a dedicated effort to breed zygotic seed into cold hardy citrus.

To do that, you'd want to take a bunch of fully zygotic varieties like Meyer lemon, ichang papeda, one of the more cold hardy pomelos, rough Seville orange or some other zygotic sour orange, then some combination of (1) breed then with each other, using ichang papeda as your main source of cold hardiness and then screen your F2 generation for hardiness (2) cross them with the handful of zygotic poncirus hybrids (eg the SuperSour series of rootstocks) and again screen for cold hardiness in the F2 generation, (3) find out which fairly cold hardy hybrids have one fully zygotic patent, ichang lemon for example, and cross it with your zygotic varieties, then screen the F1 generation for zygotic seed, and (4) cross them or some of your good F1s and F2s with the nucellar but very hardy hybrids and varieties like 5*, Dunstan, Changsha, then backcross those F1s with your fully zygotic plants again so that hopefully you'll have some fully zygotic F2s.

Lots of options, but none of them would get you results in a single generation. You'd probably need another two generations to then select for the best cold hardiness. That's at least a lifetime of breeding work. However, were someone to do this, it would make cold hardy citrus breeding much, much easier. And if you went for an four options, and were sure to include a wide variety of sources of zygotic seed (lemon, pomelos, sour orange) you'd end up with a lot of genetic diversity to work with to get the fruit quality you'd need for something not just edible, but good.

8B is probably one of the better zones for attempting a project like this.


  Nothing against what was said above, if you want that much genetic variation in your population.  But there are already 4 mostly zygotic mandarin x Ponciris hybrids in use.  US 1279, 1281 and 1282 are more than 95% zygotic, and 852 is about 85% zygotic.  And Kumin has some F2 citranges that have survived 4 (or is it 5 now?)zone 6 winters.  And he has collected some citrimelos and such to bring into his population.  I think he is closer to success and will have an easier time than is being talked of here.
I am trying about the same way but I'm way behind him, in spite of his sharing his stock with me.  We are both in zone 6, but our climate and soil are different, and our time and space are different.
Also I am also working toward a hardy finger lime.  I didn't know that Australian citrus don't cross well with Ponciris.  However, at least one finger lime x Ponciris exists in Florida.  They aren't sharing it.  At least not with me.
I hope my saying this keeps others from trying to breed hardier citrus, and trying different methods, and working toward different goal.  I have been in touch with someone in Tennessee zone 7,  working on hardier kumquats via kumquat x Ponciris.  I think he will be successful in a few generations.
I wish success to all of us.  And have fun!

9
Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« on: August 18, 2023, 01:34:55 PM »
Thanks for sharing.  You are making progress.

10
Citrus General Discussion / Re: graftingg additional roots on trees
« on: July 15, 2023, 03:16:16 PM »
There are enough branches I can try several ways.  So I'll try rooting cuttings too.

11
Citrus General Discussion / Re: graftingg additional roots on trees
« on: July 15, 2023, 02:29:50 AM »
Then I maybe should do a cleft graft onto the two rootstocks I was going to  graft onto the Etrg.  And that would reduce the size of the Etrog tree a little making it less of a load on the small roots.

12
Citrus General Discussion / graftingg additional roots on trees
« on: July 13, 2023, 07:31:05 PM »
There is already a couple of threads on grafting additional rootstocks on a tree to help it grow faster and/or better.  One is "Multiple rootstock grafting" on a non-citrus.  I think there was one on citrus but I couldn't find it.  So I'm starting a new thread because I need advice.
A year ago I bought an Etrog from Logees and got a nice healthy tree but in a tiny pot.  I potted it up but it quickly declined and died.  I think it didn't have enough roots to absorb enough water in the hot dry windy climate here in central Kansas.
So I decided to buy another and graft on 2 more rootstocks.
The Etrog is about 35 cm tall and in a pot about 5 cm square and 5 cm deep.  The rootstocks I have are Citrus x Ponciris but I don't know which variety.  They are a little smaller than the Etrog.
My plan is to plant all 3 in a 3 gallon pot and use approach grafts to join them and cut off the tops of the 2 new rootstocks after the grafts have taken. 
One problem I see is keeping the Etrog alive until until the grafts take.  Another problem is that it is up to 100 F just now and this is a bad time to do all this.
Any advice is welcome.

13
Citrus Buy, Sell, & Trade / Re: Finger lime in bloom. Need pollen.
« on: June 16, 2023, 11:05:57 PM »
Here's a link on how to store citrus pollen.
file:///C:/Users/User2/Downloads/hortsci-article-p81-1.pdf
Cold, dry and oxygen free.  Either Nitrogen or carbon dioxide.  I'll be rereading that paper to get more details.
 Searching youtube only gave me diretions on how to self pollinate citrus to get more fruit.

14
Citrus Buy, Sell, & Trade / Re: Finger lime in bloom. Need pollen.
« on: June 15, 2023, 10:48:04 PM »
With grapes pollen it needs dried out and stored in a freezer to last a year. Even then it's not as good as fresh and after a year goes down to barely viable at all. Fridge helps some. Room temperature won't stay viable for too long. Maybe a few months.

What about sun dragon? 1/8 poncirus and good fruit without off flavors.

So its hybrids would get 1/16 Pt from it.  Not a lot but if mated with the right other parent could give something interesting.  Not every cross has to be aimed towaed my zone 6.  You folks in zones 7 and 8 could use more diversity in your citrus groves.

15
Citrus Buy, Sell, & Trade / Re: Finger lime in bloom. Need pollen.
« on: June 15, 2023, 02:25:59 PM »
I agree that it  would be a good cross.  And it would add some cold hardiness abd genera vigor.   But my first priority is winter hardiness.  Crossing with Morton give its hybrids  another zone or maybe two.  Sp Ponciris is my first choice.
I wasn't prepared because I didn't expect my finger lime to bloom so small.  My bad.
I'm thinking I might start a library of citrus pollen so if anyone wants pollen for a cross, I can send it.  And if anybody has pollen they might like someone to use, it can be stored until wanted.

16
Citrus Buy, Sell, & Trade / Re: Finger lime in bloom. Need pollen.
« on: June 05, 2023, 02:48:18 AM »
I'll try it,  I had to google Banpeiyu  to find out what it is,  Not many buds left  But if pollen doesn't get here in time for these flowers, I'll freeze it for later.

17
Citrus Buy, Sell, & Trade / Re: Finger lime in bloom. Need pollen.
« on: June 03, 2023, 02:44:56 AM »
That would be great if it works out.

18
Citrus Buy, Sell, & Trade / Finger lime in bloom. Need pollen.
« on: June 01, 2023, 09:41:22 PM »
My finger lime just opened several flowers this afternoon.  I had not even noticed it had buds.  So I'd like to pollinate it with P. trifoliata or its hybrids.  Second choice would be seedless Kishu.  Third choice would be any of the hardier citrus.  Would pay for your time getting the pollen and mailing, either in money or a share of the seeds, if any seeds come of it.

19
Those with low % zygotic are not dead ends if they make normal pollen.  But this list will help people choose seed parents,

20
Citrus General Discussion / USDA says silicon helps citrus
« on: May 25, 2023, 11:44:46 AM »
Today Citrus Industry news says 50 to 100 ppm improves citrus health including disease resistance and cold tolerance.
It also said several products have come out with silicon at those strengths.  Also said several products already had silicon in them but lumped silicon in "inert ingredients".  Names of such products weren't mentioned,

21
The relative hardiness of different cultivars can vary from year to year or place to place.  One variety could better survive mid winter cold but another might better take early fall or late spring cold.

22
Cold Hardy Citrus / Re: Poncirus hybrid crosses
« on: May 01, 2023, 02:28:14 PM »
I just posted a couple of posts on another thread that could have been posted here.
https://tropicalfruitforum.com/index.php?topic=50899.0;topicseen
Most of you on this thread probably know everthing I put on those posts so I put it there where there were some with less background although some are on both threads and giving good advice.

23
Citrus General Discussion / Re: Breeding citrus what affects things
« on: May 01, 2023, 02:12:37 PM »
In what order do you make your crosses?  Often the plants decide for you.   These are in bloom so you make the cross both directions hoping to get enough seeds to find a seedling or seedlings that are a step toward your goal.  But if you are blessed with many flowers you will prefer some crosses over others.

I want a seedless winter hardy finger lime.  I start with.Ponciris+. Kishu Seedless mandarin, and a finger lime.

Pt+is winter hardy and the fruit, I'm told, is like a very sour orange'  It has zygotic seeds.

Kishu Seedless has a dominant gene for seedless.  The origional Kishu is said to give nucelar seeds.  It can only be used as a pollen parent.  Half of its seedling will be seedless and may be highly nucelar.

Finger lime has the interesting fruit though I have read that the flavor is not the best.  It gives zygotic seedlings but seeds are small perhaps giving weaker seedlings.

So if I was in zone 8, or even zone 7, I would prefer to do this.   Finger lime X (Pt+ X Kishu Seedless).
But being in zone 6 where more hardiness will be needed, I'll prefer Pt+ X (Finger lime X Kishu Seedless), or
( Pt+ X  finger lime) X (Pt+ X Kishu Seedless}'  Either way I'll have a population that is 1/2 Pt+, 1/4 finger lime, 1/4 Kishu.  but in this second way I'd not be using finger lime as a seed psrent.   Selections from this population could be crossed with selections from an F2 population from the (Pt+ X finger lime).  So this new population would be 1/2 Pt+. 3/8 finger lime , 1/8 Kishu Seedless.
 


24
Citrus General Discussion / Re: Breeding citrus what affects things
« on: May 01, 2023, 01:18:27 PM »
Pagnr gave a lot of useful information.  I want to add a bit more.
He gave an example of a triploid hybrid with A, B, and C sets of chromosomes.  And he treated them as if each set stayed together.  In fact each set has 9 chromosomes  A1, A2, A3, etc.  B1, B2, B3, etc.  and the same for set C.
A1, B1, and C1 chromosomes are similar having evolved from an origional ancester X with chromosomes X1, X2, X3, etc.
A1, B1, and C1 are still enough alike that one can replace another and still be viable.  But they will be different enough that some, about 1/9, of the traits, will be from the the species that donated that chromosome.  So any pollen grain should have a 1, 2, 3, 4, 5, 6, 7. 8, and 9 but not always from the same species.  One might be A1 B2 C3 A4, B5 C6, A7, A8, B9. o any other combination having one chromosome of each number.  A few of the combinations might not be able to survive, but most will.  A few will be what you had hoped for, or at least a step in the direction.  Most are rejects.

Now another complicacation.  A1, B1, and C1 chromosomes don't stay as they were when you started.  During the formation of pollen and egg cells crossover happen.  I don't know how often they happen in citrus but the crops I have worked usually have about 2 per chromosome per generation.

chromosome from one species has genes
ABCDEFGHIJKL

chromosome from a different species has genes
abcdefghijkl

after a crossover you have
ABCDefghIJKL
abcdEFGHijkl

This exchange usually happens on each chromosome pair per generation, in a different location each time.  So the deck slowly gets shuffled/

25
Cold Hardy Citrus / Re: Poncirus hybrid crosses
« on: April 21, 2023, 12:44:52 PM »
As Kumin said above, selfing is not always a bad thing.  But as he said elswhere, he is planning to cross a citandarin that is about to bloom with a citrimelo.  I think it was.  It was aday or two ago that I read that post.
The ideas expressed here are good ones.  I'll point out that US 852, which was mentioned, can be a useful parent.  It is listed as 85% zygotic.  But US 1278, US 1281, and US 1282 (I hope I got those numbers right) are better at more than 95% zygotic.  But the idea is the same.
Quick turn over is good.  So after selecting for winter hardiness, sending scions south to a longer growing season would speed things up.
As for flavor, Ponciris+ is too sour but the juice with water and sweetener added is a good drink.  So selection for more sugar and less acid would make it edible.  Fewer seeds. bigger. and less hard peel Would make it better.
Kishu Seedless mandarin has a single dominant gene for seedless.  So when its pollen is used, half its seedlings will be seedless.

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