Citrus Breeding

[sheaper]

Im interested in breeding zone 7/8 worthy edible citrus varieties and have my eyes on a couple ideas. Would it be a good idea to use Keraji as the seed parent and maybe Kishu/Clem-Yuz/Thomasville as pollen donors?

I have no idea what I’m doing as far as breeding goes and will be researching a lot but have lurked on this website for quite some time.

Any advice welcome Thanks!

[a_Vivaldi]

Hi!

'tis a noble cause. It's always good to see people working on it.

So, zone 7 and zone 8 are gonna be pretty significantly different challenges. Keraji, Clem-yuz, and thomasville are all hardy in many parts of zone 8. Whereas zone 7a is certain death for almost anything that isn't pure trifoliate.

I don't think Keraji has an especially high rate of zygotic seed, but I don't know for sure myself. While not impossible, it's significantly more work to use the more nucellar varieties. But, there aren't many highly zygotic varieties, so it's a major constraint of its own. Your growing conditions will probably dictate your strategy a bit. If you can grow out a bunch of seeds and have space for a lot of seedlings or plants that you later cull for being clones, then working with nucellar varieties isn't as big a deal. If you are space-constrained, or will be growing out in pots that you have to take care of, then focusing on zygotic varieties is probably a better idea.

Kishu is probably a good idea, especially for a final step in breeding, as I believe it's seedless gene is dominant. As a pollen parent is definitely preferred.

[Wahl]

I'm growing Thomasville with protection, lights and on the coldest night cover it.

[a_Vivaldi]

Right, I meant unprotected. With *enough* protection, you can grow almost anything anywhere.

[Mulberry0126]

Flying Dragon has some percentage of zygotic seeds, so using it as the mother and Keraji/Kishu/etc. as the pollen parent might be promising.
Regardless of which one is the mother however, I think it would be interesting to see what these crosses would yield since citrandarins like US-942/US-852 aren't too bad in taste considering they are 50% trifoliate and hardy to some zone 7 climates.
I'm not sure about this, but back crossing with trifoliate to have a hybrid that is only 25% mandarin might also yield something very hardy.
Taste will always be a concern but as long as it makes a decent juice most people will be happy to grow any kind of citrus in a colder area. One of my interests is recreating Thomasville citrangequat but with a citrandarin and kumquat. I think the resulting hybrid could taste quite good!

[a_Vivaldi]

Citrandarin and kumquat should be a pretty doable one, since most kumquats would be usable as mother plants. Depending on the citrandarin parent and a bit of genetic random chance, you might even get something that you could easily get a zygotic F2 population from, which would be a good way to try and maximize cold hardiness and good dormancy on the one hand, and better mandarin and kumquat like fruit on the other, giving you something even better than Thomasville. Might take a fairly large F2 population to get what you want, but totally realistic.

[sheaper]

Thanks so much for all the replies already!

I was choosing keraji mainly because I read that it was highly zygotic but maybe that isn’t the case. I know I won’t get a zone 7 variety from that but was hoping for something similar to Thomasville in hardiness.

At my Parents house I have a US-942, X-639, Kuharske, Flying Dragon, and Rubidoux planted in a line and are coming to fruiting maturity size soon.

At my house I have a ton of different varieties that I could collect pollen from etc so my options are almost endless there.

So do you just freeze the pollen? Any special requirements for doing that?

Thanks so much. I love this forum
 

[Till]

Pollen must be dried (best at 30°C but probably not warmer). Dried pollen can be frozen at -20°C for at least a year.

The best choice for crossing would in my view be crossing two citrandarins with each other or crossing a citrumelo with a citrandarin thus getting something orangelike. But it is always good to try new things. I had difficulties using Keraji as mother plant because it blooms later than many other hardy citrus plants. And I got a greater number of polyembryonic seeds. I also pollinated Poncirus with frozen Keraji pollen. But it is very doubtful that I got hybrids. The seedlings look too ponciruslike I would say.

Still, you my be more successful!

[Mulberry0126]

Pollen must be dried (best at 30°C but probably not warmer). Dried pollen can be frozen at -20°C for at least a year.

The best choice for crossing would in my view be crossing two citrandarins with each other or crossing a citrumelo with a citrandarin thus getting something orangelike. But it is always good to try new things. I had difficulties using Keraji as mother plant because it blooms later than many other hardy citrus plants. And I got a greater number of polyembryonic seeds. I also pollinated Poncirus with frozen Keraji pollen. But it is very doubtful that I got hybrids. The seedlings look too ponciruslike I would say.

Still, you my be more successful!

I like the idea of a citrumelo/citrandarin cross, kind of like replicating the pummelo/mandarin crosses. Sacaton seems fairly zygotic from my limited experience as well as US-852/942. I have some young grafts blooming so I might save the pollen from these.

[Lauta_hibrid]

I was posing the same challenge and I'll share with you some of what I'm already consolidating: from scratch I would start with a cross between Pummelo Siamese acidless x Poncirus (fast flowering or Poncirus+) from this a kind of "citrumelo" would be left.

From Pummelo, its "acidless" gene is inherited, reducing the acidity of the hybrid, it also enlarges the fruit and gives it a grapefruit flavor.

and the Poncirus would give resistance to the cold.  the Poncirus+ has a better flavor and the fast-flowering Poncirus has the fast-flowering gene (it seems that it is not dominant but in the 2nd generation it could appear).

If you want to work on existing varieties, there are some interesting ones with tolerance ranges suitable for 7A:
US852 (Changsha x Poncirus)
Tai Tri (taiwanica x Poncirus)
Swingle citrumelo.

These have a good proportion of Zygotic seeds and thus you achieve hybrids.

[sheaper]

Wonderful information, thank you all so much this helps a lot. 

Does anyone have an idea of what percentage zygotic Keraji is? 

On this forum there is a list of all known breeding varieties and their qualities and there it has Keraji as "highly" zygotic.

Thanks!

[Till]

A cross of Citrumelo x Changsha Citrandarin would have the advantage that frost hardiness is very likely. A good hardiness cannot be garantied but since you have 2 Poncirus grandparents involved and one hardy mandarine it is very probable that seedlings can at least take -15°C / 5°F. And since two of the grandparents are sweet (Grapefruit and Changsha) there is some hope that the hybrids will also bear sweet fruits.

The toll regulations are as often a great problem. We have in Europe a fully hardy Changsha Citrandarin (US 899 F2 from "Usirius") with zygotic seeds and we have a kind of sweet Poncirus (Poncirus Kinga) with full hardiness which is actually also a hybrid. The former has fruits with medium acidity (sour but less than Poncirus), good mandarin aroma and mild Poncirus flavour. The latter one is said to be sweet and to resemble Poncirus in other regards.

Perhaps yopu have similar types in the States.

[Lauta_hibrid]

I'm waiting for my fruit from Satsuma Okitsu x Poncirus.  I'll see if I managed to hybridize any seeds.  I prefer Satsuma as a mandarin since it is resistant to cold but the most important thing is that it is early, and for cold climates the important thing is that it matures before frost.  If it comes out later I could do a cross with another Poncirus hybrid and continue improving it

[a_Vivaldi]

Some interesting variation in US-852 seedlings. I don't know where these highly serrate and lanceolate leaves are coming from. I think these seeds were originally from Stan McKenzie and for to me a bit of a roundabout way, in which case there's no telling what the pollen parent is. Thoughts?

[Mulberry0126]

That's a very unique leaf form, I would hold onto it for sure. I saved some of my unifoliate US-852 seedlings in the off chance they are better tasting and still hardy. So far, their leaves taste pleasantly like a normal citrus.

[sc4001992]

I have a question for you on this cross:

"Pummelo Siamese acidless x Poncirus (fast flowering or Poncirus+)"

I want to use the Banpeiyu for my pomelo since I have a large tree with fruits now so I can do it on the next flower cycle.

Which fruit do I get the pollen from, and which fruit will should be the female to hold the fruit?

[hardyvermont]

I have a question for you on this cross:

"Pummelo Siamese acidless x Poncirus (fast flowering or Poncirus+)"

I want to use the Banpeiyu for my pomelo since I have a large tree with fruits now so I can do it on the next flower cycle.

Which fruit do I get the pollen from, and which fruit will should be the female to hold the fruit?

Pummelo has mostly seeds from sexual crosses.  It would be the female parent.

[sc4001992]

ok, thanks.

[Till]

I agree that Pumelo is best as the female parent. I had, however, mysterious problems use my Chandler as female parent. I know that other were more successfull. But I for my part never got seeds from the combination Chandler (mother) x Poncirus (father). I got at least one hybrid Poncirus (mother) x Chandler (father). What also worked was Chandler (mother) x (African Shadock x Poncirus) (father). Seedlings of the latter cross differ greatly from pumelolike to ponciruslike.

I only say that that you better try both directions of the cross even though Chandler as mother seems to be the best choice. Plant can react quite erratic. What seems probable in theory is sometimes difficult in practice. And what other could do you may have problems with.

[Lauta_hibrid]

Regarding the use of C. maxima (Pummelo) as a mother, I give you my first experiences: I had only 1 harvest last year and this year I have 5 fruits in different strains of C. maxima.  The first year I mixed Pummelo x: kaffir, Willow left mandarin, Buddha hand and Moro orange.  One fruit of each gave me 24 seeds on average each, but when pollinated by Buddha Hand it only had 6 and they were very small.  So he decided that by having statistically few fruits you could get some without seeds, but not because of the pollen.  Doing reciprocal crossings is great and seems ideal to me.  Chandler, for his part, I don't know if it is triploid, does anyone know?  because that can be detrimental and not be very fertile and if it hybridizes it can form 2n or 3n hybrids, so the mixtures could come out unequal (2 parts Chandler and 1 part Poncirus).  I will see this year what results I have from C. maxima x poncirus and x citrange troyer and I will tell you about the seed production.

[sheaper]

Regarding the use of C. maxima (Pummelo) as a mother, I give you my first experiences: I had only 1 harvest last year and this year I have 5 fruits in different strains of C. maxima.  The first year I mixed Pummelo x: kaffir, Willow left mandarin, Buddha hand and Moro orange.  One fruit of each gave me 24 seeds on average each, but when pollinated by Buddha Hand it only had 6 and they were very small.  So he decided that by having statistically few fruits you could get some without seeds, but not because of the pollen.  Doing reciprocal crossings is great and seems ideal to me.  Chandler, for his part, I don't know if it is triploid, does anyone know?  because that can be detrimental and not be very fertile and if it hybridizes it can form 2n or 3n hybrids, so the mixtures could come out unequal (2 parts Chandler and 1 part Poncirus).  I will see this year what results I have from C. maxima x poncirus and x citrange troyer and I will tell you about the seed production.

Buddhas hand has no seeds though right? I wonder if thats just what you get when you try to cross BH with about anything?

just thinking out loud here

[a_Vivaldi]

Pretty funny looking Dunstan seedling there. Kinda sus.

[bussone]

Im interested in breeding zone 7/8 worthy edible citrus varieties and have my eyes on a couple ideas. Would it be a good idea to use Keraji as the seed parent and maybe Kishu/Clem-Yuz/Thomasville as pollen donors?

I have no idea what I’m doing as far as breeding goes and will be researching a lot but have lurked on this website for quite some time.

Any advice welcome Thanks!

Being as you are in South Carolina, I would recommend you give Stan Mckenzie a call.
http://mckenzie-farms.com/

[Mulberry0126]

Pretty funny looking Dunstan seedling there. Kinda sus.

Kinda sus indeed...looks different from my Dunstan seedlings which were incredibly consistent.

[a_Vivaldi]

The seeds all looked the same, so I may well have gotten lucky with something zygotic. If so, it's still surprising to see bifoliate juvenile leaves and monofoliate older leaves with their long, long petioles.

I don't know where the mitten shaped leaves came from. The long petioles would make some sense if a papeda was somewhere in the recent ancestry, which given that these seeds probably came from Stan McKenzie originally, I wouldn't be surprised if some ClemYuz or ichang lemon pollen was involved. Or perhaps bloomsweet? I know he has some of them and I think they have that petiole thing too.

The leaves smell better than my other Dunstan seedlings. More bright orange and lemon, though there is still a kind of bitter or resinous smell in there as well I think. Once it's a little bigger I'll break some leaves for a better smell test and taste some as well. I'm pretty sure there's some trifoliate bitterness in there, which would suggest it is a Dunstan seedling and not an errant seed from something else.

Hard to tell just yet. I'll keep an eye on this one.