Author Topic: new thoughts on breeding hardier citrus  (Read 4469 times)

SoCal2warm

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Re: new thoughts on breeding hardier citrus
« Reply #25 on: November 11, 2021, 12:20:13 AM »
Woodlanders ichang papeda is seed-grown, would be a gamble but I guess that's a way.
If the Ichang papeda crossed with something else, I think it would be obvious from the leaves and fruits that it was not Ichang papeda. Ichang papeda has very symmetrically sized leaves when it comes to the winged petioles.
I believe Ichang papeda is very zygotic (seeds resulting from sexual recombination), but assuming the plant crossed with itself, I would expect it to come out mostly true to seed.

Of course my personal experience of Ichang papeda plants not seeming to be very cold tolerant might counter that theory.

If this species was as cold tolerant as everyone else seems to observe, then I think it would have a lot of potential for breeding, judging by the quality of what I've tasted from the fruits. Especially anyone specifically trying to breed something with more of a lemon or lime flavor rather than "orange" flavor. Ichang papeda only takes one cross with something else to get something edible. Poncirus trifoliata, on the other hand, takes two or three. I'm going to say Ichang papeda is probably on about the same level of edibility as a Thomasville citrangequat, the best poncirus hybrid I've tasted. Just my personal opinion. (I'd imagine many would say the Thomasville citrangequat is a little bit better)
It's extremely rare for poncirus to cross just one time and result in something that is possible for anyone to eat. US-852 citrandarin and Dunstan citrumelo might be the best two. Still some bad poncirus flavor but some people can manage to eat them without too much problem. (I personally have not had an opportunity to taste either yet, but am going by the reports of others)
« Last Edit: November 11, 2021, 12:38:19 AM by SoCal2warm »

Zitrusgaertner

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Re: new thoughts on breeding hardier citrus
« Reply #26 on: November 30, 2021, 05:46:18 AM »
Have you ever thought of Ichang Papeda? Is it suitable for your climate zone?
Ichang Papeda grows much better than Poncirus and some flower after 3 years, but not all.
Poncirus grows so unspeakably slowly that I am already wondering whether it is at all suitable for my climate.

Mikkel,

there is quite a lot of variety with PT seedlings. Some are vigorous others not at all. You have to select the vigorous ones.



850FL

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Re: new thoughts on breeding hardier citrus
« Reply #27 on: January 08, 2022, 05:34:12 PM »
Keraji, Changsha, Kishu...
Anybody consider hybridising PT with mangshanensis mandarins, and other pure lineages (not necessarily just pure mandarins, but with any pure citrus?) Maybe utilizing pure genes would be helpful in some respect, like less ambiguity related to the prediction and expression of gene sets? Whereas the expression of genes of the progeny from say, a 'complex-hybrid x PT-hybrid' would be quite a lot less predictable?
At least, perhaps 'pure x PT' hybrids could be used as F1 parents for further hybridising.. Anybody catch that drift or am I delusional?
Also, saw a video where citrus breeders grow their hybrid seedlings pretty much as straight sticks to induce the earliest possible flowering (as opposed to bushy w/ side branches). In case you may have not known.. cuts down time.. although I don't know if this applies to all citrus types..

Walt

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Re: new thoughts on breeding hardier citrus
« Reply #28 on: January 08, 2022, 08:36:23 PM »
I know nothing about mangshanensis mandarins.  I'll have to do some searches on those. 
Its true that some of the pedigrees of what I think of as F1s include Changsha which is not pure mandarin.  I don't see this as a problem.  I know of someone who is breeding for zone 7 kumquats.  He is using Meiwa kumquat, which I thought was pure kumquat.   But a few days ago I was reading a publication that quoted Swingle saying he didn't believe Meiwa is pure kumquat.  I certainly wouldn't know the difference.
Kumin has had amazing success using C-35 seedlings,   C-35 is Rusk orange x Pt.  All oranges are from interspecific hybrids.
I'm sure many, most, domestic citrus have been crossed around.  An exceptipn is finger lime.  And it seems some plants in the USA sold as finger lime are an F1 hybrid. 
I don't see a problem with using impure citrus in breeding.  My issue is where can I find useful genes.

850FL

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Re: new thoughts on breeding hardier citrus
« Reply #29 on: January 08, 2022, 11:01:11 PM »
The mangchanensis are from the zone 9 mountains close to zone 8. I think the Changsha are probably from right around there too. They are obscure wild mandarins but look cold hardy like Changsha. You could use a 'mang x PT' and breed that rudimentary with something sweet like perhaps navel orange or hybrid something and it would definitely be cold hardy (maybe not quite to z6.. but perhaps some seedlings?) and have pure tangerine genetics involved. Mangschanansis apparently contain the same amount of sugars but more citric acid than most domestic mandarins, according to this article -    https://www.sciencedirect.com/science/article/pii/S1674205218301874
- and also contain 'abundant healthy phenolic compounds and antioxidants'. I personally like zangy mandarins and mandarin hybrids. They are actually by far my favorite citrus. I don't like just sweet and bland like some satsumas are, at least the ones grown around here. The tommy Atkins trees of citrus. Almost like wasted space and effort with some of them. The intense tangy mandarins are a lot more nutritious. Clementine is great but even more tang would be better. Just not so sour as say a Calamondin or lime so it's still enjoyable. It would be cool to even have purple flesh with anthocyanin benefits, so blood oranges could replace navel with that theoretical hybrid. I think Moro is the sweetest? I do enjoy sweet but accompanied by a lot of tang. Y'all's ponciris+ could be the PT in that hybrid to get rid of the nasty. So I stand by
['ponciris+ x (good mang selection)'  x  'Moro x minneola' ]
Or replace minneola with navel or something sweet. Even satsuma. I just like tangelos.
« Last Edit: January 09, 2022, 01:31:28 AM by 850FL »

hardyvermont

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Re: new thoughts on breeding hardier citrus
« Reply #30 on: January 08, 2022, 11:21:34 PM »
Crossing Satsuma with Poncirus yields a sour fruit. Based on the link above, domesticated Satsumas have less sourness, so would be the preferred choice as the sourness is not coming from both parents.

If these wild species were available, it would be good to try for hardiness.

850FL

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Re: new thoughts on breeding hardier citrus
« Reply #31 on: January 08, 2022, 11:53:51 PM »
I think z6 would be almost unfeasible (not impossible) to breed for something really good but could end up with some good selections for z 7 and 8 with y'all's efforts if they live.
I still stand by my above theory with some modifications
['Ponciris+ x mangschanensis' x mangschanensis'] x ['Moro x navel']
With this, there would be beneficial genes floating around for cold hardiness, anthocyanins, low seediness, low bitter, quality fruit, easy peel, tang (hopefully not excessive). Although, other genes for seediness, small fruit, excess sour also present.
You could substitute mangschanensis with another tangerine that is hardy in the teens F I suppose. I guess 'pure' might not matter too much here but don't discredit that purity could have it's place in some aspects of breeding.
Then navel could perhaps be replaced with something else sweet. I would like to be able to replace navel with minneola, sunburst, cara cara, clementine, Kishu, satsumas, if any of those would even work out nicely. Who is to say the relative sweetness in any of those domestics would even be accurately expressed? anyway I think this general set of genetics could create something really good and still quite cold hardy, but I wouldn't count on z6 exactly.. I would predict the F5 or F6 (basically the end product seedlings of all that hybridization) to probably generally withstand zone 7..
Ponciris+ I assume can withstand somewhere around -15 - -20 F
Satsumas low teens F
Minneola mid teens F
Wash navel & cara cara high teens F
Clementine mid teens F
Sunburst 20F
Mangschanensis probably mid to low teens F
Can one predict general cold hardiness for a batch of hybrid seedlings accurately? For example, could 'PT x wash navel' seedlings be predicted to withstand around 0F since average cold hardiness -20+19/2= -2? I realize cold hardiness traits are inherited not averaged but can it generally be predicted to work out like this with most cold hardy citrus hybrids?
« Last Edit: January 09, 2022, 01:38:55 AM by 850FL »

mikkel

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Re: new thoughts on breeding hardier citrus
« Reply #32 on: January 09, 2022, 07:58:29 AM »
Roughly speaking, the greater the number of seedlings, the greater the chance of finding one or a few that are more cold tolerant.
Hybrids do not have uniform characteristics, but a variance of traits (similiar to gaussian normal distribution). F1 hybrids are usually still quite uniform (if the parents are not already hybrids), F2 are then very broadly spread in their characteristics.
Obtaining sweet fruits I think, is more about "less sour" genetics than "higher sugar level "genetics. It seems sourless is often recessive inherited and needs therefor backcrossing.

850FL

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Re: new thoughts on breeding hardier citrus
« Reply #33 on: January 09, 2022, 10:30:20 AM »
Quote
F1 hybrids are usually still quite uniform (if the parents are not already hybrids), F2 are then very broadly spread in their characteristics.
That's what I was pretty much getting at with using pure ones.
Quote
Obtaining sweet fruits I think, is more about "less sour" genetics than "higher sugar level "genetics. It seems sourless is often recessive inherited and needs therefor backcrossing
That's useful!

Walt

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Re: new thoughts on breeding hardier citrus
« Reply #34 on: January 09, 2022, 10:48:25 AM »
What Mikkel said about value of population size was demonstrated by Kumin's 20,000 C-35 seedlings.,
Only 3,000 of them counted as the rest were nucellar.  It gave 12 that have 3 zone 6 winters survived in good health.  Several others survived with damage, some died to the ground but came back,  Given that so many survived, I now think this is going to be easier than I thought.  But I said that above, didn't I?

mikkel

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Re: new thoughts on breeding hardier citrus
« Reply #35 on: January 09, 2022, 12:46:31 PM »
Quote
F1 hybrids are usually still quite uniform (if the parents are not already hybrids), F2 are then very broadly spread in their characteristics.
That's what I was pretty much getting at with using pure ones.
For me, the F2 is the interesting one, because that is where the really interesting things happen. In pure parental lines, the F1 generation consists of uniform types with mainly intermediate traits. But if you want to transfer a trait (e.g. cold tolerance) to another variety with good traits, it happens in the F2.
The F1 will be intermediate between the parents in fruit quality and cold tolerance, the bad of both worlds, so to speak.
In the F2 and the following generations the traits split and new trait combinations appear (e.g. ideally good fruit and cold tolerance) these have to be selected, therefore mass is needed. Since recessive and dominant as well as other genetic factors play a role, it varies from species to species which hybridisation is used in the following generations.
Of course, this is idealised theory and varies in reality. Especially when the parent varieties are not homozygous or / and already have hybrid traits.
Kumin's trial is, in the sense of this consideration, to interpret an F2 mass selection, the generation in which the splitting and recombination occurs for the first time.
For this reason I also try to work with F1 hybrids as crossing partners, this saves a lot of time.
Of course, this does not mean that hybridising pure species is not also useful. I also find mangshanensis very interesting.


Quote
Obtaining sweet fruits I think, is more about "less sour" genetics than "higher sugar level "genetics. It seems sourless is often recessive inherited and needs therefor backcrossing
That's useful!
[/quote]

there is a thread about it:

https://citrusgrowersv2.proboards.com/thread/728/inheritance-low-acidity
« Last Edit: January 09, 2022, 01:27:57 PM by mikkel »

kumin

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Re: new thoughts on breeding hardier citrus
« Reply #36 on: January 09, 2022, 04:52:32 PM »
Large populations increase the number of throws of the genetic dice. Heavy selection pressure and elimination of plants expressing undesirable traits should skew the results in a favorable direction, provided those genes are present within the population.
« Last Edit: January 10, 2022, 04:18:26 AM by kumin »

Walt

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Re: new thoughts on breeding hardier citrus
« Reply #37 on: April 03, 2022, 04:04:15 PM »
This morning I saw the first flower about to open on US 1279.  That's a mandarin x Pt that is more than 95%zygotic.  I don't have anything here to cross it with. 
Kumin's C 35 citrange F2 s haven't put out any new growth this spring, though they are looking good.
But US 1279 can be selfed and give F2 seedlings provided the fruit don't drop as some do.
So I'm excited.

kumin

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Re: new thoughts on breeding hardier citrus
« Reply #38 on: April 03, 2022, 04:40:17 PM »
My first F2 C-35 citrange seedling to fruit appears to produce nucellar seeds. The pollen should be viable, however. The tree is full of flower buds and should bloom as soon as temperatures rise.
I'm impressed that your 1279 is flowering, there's obviously little wait from rootstock to mature phase.
« Last Edit: April 03, 2022, 05:20:29 PM by kumin »

Walt

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Re: new thoughts on breeding hardier citrus
« Reply #39 on: May 12, 2022, 10:47:27 PM »
3 weeks ago my pure P. trifoliata that I've had in the ground for several years first broke domorancy
US 852, 1279, 1281, and 1282, Ponciris+ seedlings  Laaz Fast Flowering, Ponciris and 3 seedlings from Kumin, and a couple of citromelos and Bishop citandarin were all protected but went dormant due to quite cool conditions.  But now all are growing, except Laaz FFP  It looks healthy so I think it will start next week.
Changsha and a kumquat stayed in leaf but with little or no growth until last week.
I lost Kishu Seedless and Etrog I think.
I'll be grafting Kumin's seedlings onto in ground Pt, but continue to protect the main plants just in case.  Kumin and I are in the same zone but our weather isn't the same.

Melenduwir

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Re: new thoughts on breeding hardier citrus
« Reply #40 on: May 13, 2022, 04:28:37 PM »
Re:  sweetness vs sourness in crosses:

Wikipedia's page on mandarins notes that the wild mandarins that gave rise to the domesticated varieties have similar levels of sugar when compared to wild sour mandarins - but up to 90-fold less citric acid than them.

Lemons famously have more sugar than strawberries, but it's their acid that makes people perceive them as sour.  I agree that the key to producing 'sweet' fruit would be to concentrate on eliminating the biochemical pathways responsible for acid production - although given that acidless citrus strains are often perceived as 'insipid' and 'not-citruslike' I'm not sure a complete elimination would really be ideal.

mikkel

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Re: new thoughts on breeding hardier citrus
« Reply #41 on: May 21, 2022, 02:45:38 AM »
There is a discussion about that on CitrusGrowersForum

https://citrusgrowersv2.proboards.com/thread/728/inheritance-low-acidity

vnomonee

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Re: new thoughts on breeding hardier citrus
« Reply #42 on: May 25, 2022, 02:17:50 PM »
Add Yuzu to the list. In zone 7 mine (in the ground) died back after 6-7f but is now coming back from the base.

I'm not too worried about citrus for eating fresh out of hand since many can be cooked into marmalades or used as lemon substitutes, yuzu x poncirus+ is definitely a goal. My potted yuzu is about to flower but I don't have any type of poncirus flower or pollen yet so that will have to wait.
« Last Edit: May 25, 2022, 04:44:51 PM by vnomonee »

Zitrusgaertner

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Re: new thoughts on breeding hardier citrus
« Reply #43 on: May 25, 2022, 03:15:53 PM »
Your yuzu is on its own roots or grafted?

vnomonee

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Re: new thoughts on breeding hardier citrus
« Reply #44 on: May 25, 2022, 04:43:07 PM »
own roots against a brick wall

Walt

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Re: new thoughts on breeding hardier citrus
« Reply #45 on: May 31, 2022, 10:23:50 AM »
Finally the Fast Flowering Ponciris I got from Laaz last summer is showing new growth.  There are 5 tiny new branches with leaves.  The longest is about one cm., which is really small, but it the start of new growth,  It is over a month behind my older established trees.  I believe this is due to transplant shock, not that these trees will always be late starting growth in the spring.Actually I'd be glad if it was late leafing in the spring.  I think that would make it less likely to be hurt be late frost.  But I think it is just due to transplant.
I don't know whether it will bloom this year.  I know it is old enough because it had 3 fruit on it when it arrived last summer.

vnomonee

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Re: new thoughts on breeding hardier citrus
« Reply #46 on: June 03, 2022, 11:01:55 PM »
Pollinated 2 castrated yuzu and meyer lemon flowers with dried poncirus+ pollen. Stored the rest in an airtight container in a small fridge. Waiting for kumquats to flower. Don't know if the pollen is viable but will report if anything happens.

vnomonee

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Re: new thoughts on breeding hardier citrus
« Reply #47 on: June 11, 2022, 07:25:05 PM »
Meyer dropped the fruit. Yuzu might have a take




Perplexed

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Re: new thoughts on breeding hardier citrus
« Reply #48 on: June 15, 2022, 09:55:44 AM »
Walt, any updates on the US 1279? Did any fruit set?

Walt

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Re: new thoughts on breeding hardier citrus
« Reply #49 on: June 15, 2022, 11:37:55 AM »
No.  A few days after I posted, there was wind that broke tree branches all over  town.  No damage to my citrus except the (very few) flowers were gone.  I had good bloom later on Laaz Fast Flowering Ponciris but nothing to use the pollen on.

 

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