Is a non-astringent American-Asian hybrid persimmon within reach?

General Fruit Growing
#1

First, a warning: Not infrequently, I come up with what I think is a really good idea for somebody else to work on. This is one of those.

Next, some background: I’ve been using some spare time during winter to become better informed about persimmon varieties, including hybrids and recent releases. This is a result, but I freely admit that I am a total novice so I may be totally wrong for reasons that I don’t yet grasp.

Now the point: It strikes me that the American/Asian hybrid JT-02 / Mikkusu is something very special. It is a direct cross of an American variety (Josephine) with a Japanese non-astringent PCNA (Taishu). So the genotype is half non-astringent. [Unfortunately, the phenotype is still astringent because the Japanese NA trait is recessive.] Moreover, in contrast to other pure PCNA hybrids in Japan (including Taishu itself), JT-02 is very cold hardy. It is also reportedly very tasty.

So I have to ask: Isn’t the obvious next step a back-cross of JT-02 with an Asian PCNA, maybe Taishu itself? Aren’t we one step away from a non-astringent hybrid? As noted in another thread, Taishu reportedly tastes great – it sells individually wrapped in Japan for the rough equivalent of $30 apiece! So back-crossing to Taishu would probably not compromise flavor. And it produces male flowers.

Of course, we’d have to test MANY crosses. In their PCNA breeding, the Japanese test thousands of offspring from each cross before ever selecting one for release. If my math is right, only 5% of the crosses of JT-02 x Taishu would be non-astringent. That’s [3 chances out of 6] x [2 chances out of 5] x [1 chance out of 4] – 50% x 40% x 25% = 5%. Plus we’d want to optimize taste and hardiness. Even so, a cold hardy, good tasting, non-astringent Asian/American hybrid seems within reach.

Reportedly, the Japanese breeding program shifted after 1992 from mainly crosses of PCNA x PCNA to (a) crosses of non-PCNAs with the Chinese PCNA (e.g., PCA x C-PCNA) and (b) crosses of non-PCNAs with both crosses and back-crosses of the Japanese PCNAs (e.g., PCNA x PVNA or PCNA x [PCA x PCNA]). As far as I know, there have been only two subsequent releases, Taiten and Taigetsu, both PCNA x PVNA and classified as PVA. So no reported successes so far with PCNA x PCA, maybe because it takes time to work through two generations.

Finally, based on published reports, there is only one other hybrid that is a cross of an astringent American or American-Asian hybrid with a PCNA: Reportedly, NBT-01-08 is a cross of Nikita’s Gift x Taishu. This could be another good candidate for back-crossing. Obviously I could be missing some cases, and I can’t know anything about work that is not yet published.

Bottom line: Shouldn’t we – and I use the pronoun “we” loosely – be back-crossing the crap out of JT-02 / Mikkusu with Taishu and/or any Japanese PCNAs with pollen?

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#2

Or maybe going the other way, try to cross Taishu with Morris Burton, or JT-02 with one of the MB descendants listed in this thread:

It sounds like these fruits aren’t truly and uniformly non-astringent, but have the genetics to increase the odds of a good cross. So, if “we” could get to work on that, that would be great.

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#3

If there is such thing, I’m not sure how big a market that will be. In the native Chinese and Korean markets, most are still astringent type. Not sure about Japanese market. I believe most of the Asian consumers still prefer the astringent type.

The non-astringent type persimmons can never catch up the flavor of the regular persimmons fully ripened. I even kept my non-astringent persimmons to get soft. But the flavor is not there.

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#4

I have Nikita’s Gift x Taishu which was labelled as Nikshoo and sold by agroforestry research trust in UK. I have no idea if this is NBT-01-08 though.

I’m moving it from a pot to my polytunnel this winter. I’ll report back one day if it ever fruits here (south west coast Ireland).

I believe it’s 7/8 PCNA kaki as NB is 3/4?

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#5

Both the Japanese and Korean breeding programs have been focused exclusively on non-astringent varieties, almost entirely on PCNAs but also on PVNAs. That’s a deliberate choice. The researchers state explicitly that non-astringency is highly preferred.

For Japan, I am aware of 13 releases 1959-2020, 11 are PCNA (PCNA x PCNA) and 2 are PVA (PCNA x PVNA). For Korea, I am aware of 8 releases 2008-2020, 9 are PCNA (PCNA x PCNA) and 2 are PVNA (PVNA x PVNA).

The “popularity” of PCAs seems to reflect availability. There are no native PCNAs in Korea and there are only a few recently discovered in China. In 1900, there were 12 known PCNAs in Japan and hundreds of PCAs. This is not because PCAs were preferred. It’s because the relevant mutation evidently arose recently; the trait is recessive; and most PCNAs produce no/few male flowers.

I’m not going to prejudge the market, but I firmly believe that a PCNA with enhanced flavor would take over. No more alcohol or CO2. No more waiting to eat goo.

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#6

I have to say, I kind of like the goo. And having to wait and/or work for it makes it more rewarding. But, having more options is always a plus.

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#7

@jcguarneri – Different genes produce non-astringency in Asian PCNAs and in any less astringent Americans. The Asian trait is qualitative (all-or-none) whereas the American trait seems quantitative (more or less). It would seem easier to achieve total success by getting one trait right than by mixing and matching.

That said, I don’t know that there is any magic in Josephine as the American mate for Taishu. “We” should try crosses of Taishu with a variety of good Americans. It would be very interesting to see if a Morris Burton daughter with only 3 American chromosomes would be reliably non-astringent.

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#8

@ jrd51

You sure can have whatever breeding programs they have. But as far as I know, most of the native consumers do not like those non-astringent types. Also both Chinese and Korean consider those non-astringent persimmon varieties as Japanese varieties. There is sentimental reason too.

There is also a huge dry persimmon market in both China and Korea. That huge market is exclusively astringent persimmon.

Also, I do not want to say the general Asian persimmon. Chinese, Korean, Japanese and Southeast persimmon markets are totally different.

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#9

I am asking other question: how could Josephine (d.virginiana) be directly crossed with Taishu (d.kaki) without much hassle? I should mention that direct crossing of the two species has been tried thousand times before without getting any hybrids. Seeds formed grew apomicts only. Creation of Rosseyanka as we know was far from easy.

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#10

From what I’ve read, it involved embryo rescue techniques.

#11

We bought both Kassandra and Rosseyanka from C England as a group purchase. We all like Kassandra much better than the Rosseyanka.

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#12

The fact that astringent D. kaki fruit can be treated with CO2 to remove astringency, but astringency in D. virginiana fruit and the hybrid Nikita’s Gift cannot be removed by CO2 treatment also seems to point to a completely different mechanism resulting in astringency (or it’s removal) with different genes controlling it.

Do any of the D. kaki/D. virginiana hybrids respond to CO2 treatment? I haven’t heard of any. Perhaps the mechanism resulting in astringency in D. virginiana will dominate and mask any potential recessive PCNA trait in a hybrid as well.

I don’t really understand all of the genetics involved to know what I’m talking about, but I’m just suspecting that in order to maintain the PCNA trait in a cross involving a hybrid like JT-02 that has been back-crossed repeatedly to a PCNA D. kaki, there might not be many D. virginiana genes left in any resulting PCNA hybrid. I wonder if the PCNA trait would ever show up in any of the offspring of a single back-cross.

Harbin’s point makes me wonder if hybrids are equally difficult to back cross with either D. kaki or D. virginiana?

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#13

Yes I know that for Rosseyanka but what about
JT- 02 ?

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#14

Hybrids are generally easy to backcross with both D.virginiana and D.kaki but in some cases embryo rescue technique is necessary to grow up the plant…one notable example is Dar Sofiyivky.

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#15

@Harbin Thanks for answering my question!

#16

Great question. I’d love to know more. Relatedly:

  1. If my notes are correct, the Ukrainian research program has released numerous hybrids described as a “direct cross of virginiana and kaki” though I assume PCAs. The variety names of the parents aren’t mentioned. The released offspring include Gora Goverla, Gora Rogers, Gora Roman Kosch, Dar Sophievki, Dr Karas. Apologies if my transcription of the names contains errors – I’ve seen multiple spellings. Also maybe you could confirm that these are actually F1 crosses [possibly they are crosses with Nikita’s Gift?]. And maybe you know what techniques they use.

Edit: Pavel clarifies below that all the Gora varieties are crosses with Nikita’s Gift.

  1. I’m assuming that once a hybrid is achieved, a further back-cross would be less difficult. Of course, this makes JT-02 / Mikkusu even more special.
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#17

Yes, I’m specifically referring to JT-02. I’ll see if I can find that reference.

Edit: per Cliff England on facebook:
https://www.facebook.com/Kynuttrees/posts/would-you-take-a-look-at-these-beauties-jt-02-mikkusu-persimmon-begun-ripening-a/1952046968306103/

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#18

LOL – I think you missed the point. People don’t buy the astringent types for the astringency. They like flavor. If they prefer the astringent types, it’s because some astringents are sweeter and/or more flavorful. The astringency is something they learn to cope with – by drying, by treatment with alcohol or CO2, by fully ripening. If we could develop genetically non-astringent fruits with superior flavor, I’m confident that the consumer would shift.

A JT-02 back-crossed to Taishu (or one of the Goshos) would be 25% American, 75% Japanese PCNA. Think of it as a Japanese PCNA with enhanced flavor. Sounds good to me!

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#19

Not really.

The non-astringent thing is mostly a Western thing. Those non-astringent persimmons can be picked and eaten without fully ripening. So it is much easier to pick early and can be shipped to remote markets without much shipping damage. It is more of a commercial thing. This is why Fuyu is almost everywhere in Asian and American markets.

But to me, eating non-astringent persimmon is like eating supermarket figs vs the figs that I can pick perfectly ripe from my own trees. The difference is day vs night. I have no interest to plant and pick non-astringent persimmons off my own trees. That defeats the entire purpose of growing my own fruit trees.

Just MO.

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#20

With the great big honkin’ caveat that I’ve only tried commercial Fuyus, Hachiyas, and Rojo Brillantes, one home-grown Nikita’s Gift, and fruit from a few wild D virginiana, I respectfully disagree with your assessment of astringent vs non-astringent persimmons, although I certainly used to think that was the case. As I’ve eaten more Fuyus, I’ve come to appreciate how good they can be. It depends on how well they were grown, how ripe when picked, and how firm they are when eaten. I’ve found there’s not usually a lot of depth of flavor when they’re crunchy, but a well-grown Fuyu can be impressively flavorful and rich when allowed to soften slightly. Part of it, too, was training my tastebuds what to look for. I no longer think of fully soft astringent persimmons as better. At least among what I’ve tried, astringent and non-astringent persimmons are equally good, just different. Whenever my hybrid trees start to produce, I may change my tune yet again. But that’s where I stand for now.

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