I’m curious about the origins of Korean persimmons, especially those that may have been imported from Japan, probably during the long occupation of Korea by Japan pre-WWII. The PCNA mutation appears to have originated in Japan, so I assume that any Korean PCNA varieties are either (a) synonyms of Japanese varieties, or (b) hybrids derived from Japanese varieties.
Case in point: According to this blog, in the Korean language “gam” is the word for “persimmon” and “dan” is “sweet.” So “dan gam” (sounds like Tam Kam?) is “sweet persimmon” aka Fuyu. So I’m guessing that Tam Kam is a variety of Fuyu.
This is mostly guesswork. Does anybody have ay actual factual knowledge of the provenance of Korean PCNAs and especially any possible synonymy with Japanese names?
Here’s something interesting from 2018, but it looks like the variety was selected a few years earlier. “‘Romang’ is the first pollination-constant non-astringent (PCNA) persimmon in Korea.” The authors acknowledge that PCNA persimmons in their country originated in Japan, and even this new variety was bred from Japanese cultivars.
So if “Romang” is the first, does that mean that Tam Kam is a synonym of some Japanese variety? And what about Gwang Yang, which is the name of the town where the variety was growing? Seems likely a synonym too.
Anyway, it’s helpful to know that as of 2018 there had been no other releases from the Korean program.
Yeah, unfortunately the NA trait in Japanese varieties is recessive. Since both Asian and northern American persimmons have 6 sets of 15 chromosomes, there would have to be 6 NA genes. That’s a tall order, even considering that 3 NA genes come from the PCNA female. As I understand it, most/all PCNAs and hybrids produce only female flowers. So it’s not clear to me (hardly a geneticist) how we ever get 3 NA genes from the male. [That’s assuming no genetic modification. But I, for one, would each non-astringent GMO Hachiyas all day long!]
There is hope, however, from a different direction. The Chinese PCNA Luo Tian Tian Shi reportedly achieves non-astringency differently, and the relevant gene is dominant. I have to believe that breeders in China, Japan and Korea are investigating crosses using this variety. This would seem to open the door to PCNA hybrids of LTTS x Asian PCA varieties. Maybe some enterprising American breeders are also looking at hybrids of LTTS x American varieties (or hybrids).
From what I’ve read, the Japanese breeding program was hampered by the facts that (1) many reliably-flowering PCNA types (e.g., the the various Gosho types) possess some less desirable traits; and (2) the better tasting / performing Fuyu/Jiro types produce flowers only erratically. Maybe what I should have written is something like, “Most better tasting/looking/growing PCNAs produce no/few/incinsistent male flowers.”
Taishu appears to have strong ancestry from Fuyu and Jiro, which I assume implies high quality. If it produces male flowers regularly and abundantly, then the prospects for improved future varieties seems good.
Except, of course, it is still very difficult to introduce desirable genes from PCA varieties into a PCNA strain without messing up the NA. It requires tedious and time-consuming back-crossing.
Ultimately I think the best hope for a PCNA Saiyo or Hachiya (or Prok) type would be from crosses with the Chinese PCNAs.
Well, reality is nuanced and evolving. I won’t say that this statement is not true, only that it used to be true but may not be true now or forever. . . .
How many Chinese PCNAs?
I know only what I read. And yes, for years Luotiantianshi was reportedly the only known Chinese PCNA. But this might not be the only unicorn, right? Is it too much to believe that the ancestor of LTTS pollinated other trees?
According to this article from 2007, “Recent surveys in China found several native PCNA cultivars in Hubei, Henan, and Anhui provinces. The use of Chinese PCNA cultivars offers a new strategy for persimmon breeding by overcoming inbreeding depression and has the potential for progressing the breeding of new PCNA cultivars.”
Prospects for success using Chinese PCNAs.
Success here seems mostly to depend on time and effort. The first Japanese persimmon research station opened just after 1900; the first breeding program was started in 1938; and new cultivars did not begin to be released in material numbers until the 1990s – roughly 50 years later. So maybe we need patience. Or maybe genetic engineering to speed up the development process.
Maybe try to get Taishu? It seems to be the top choice in Japan, judging from recent releases. Or it was 20-30 years ago when those crosses were first made. Advantages seem to be (1) reliable pollen, and (2) ancestry from Fuyu and Jiro. The challenge is that you want American cold-hardiness combined with Asian PCNA non-astringency, all with good flavor.
What you don’t want is a lot of seedlings with more (astringent) Americans ancestry. So suppress the virginiana pollen.
p.s. I should add that I have no idea whether Taishu (or any Americans) could readily pollinate the hybrids.