“don’t feel lost”
alright,
Dax
Are there any AG schools breeding persimmons in the US?
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A Chimera is any living thing composed of 2 or more genetically distinct types of tissue. As an example, some humans are born with both female and male cells in their body. They may have a range of sex organs and body shape and type. The cause usually gets down to 2 or more eggs fusing inside the mother just after fertilization. Something similar can happen with plants where two or more genotypes make up a single plant. A plant would be referred to as a chimera if two different genotypes are expressed on the same plant part. I have seen leaves that were 1/2 thin and normal and 1/2 glabrous and crinkled. This would be called a chimera because a single plant part (leaf) shows two different genotypes.
A bud mutation is a type of sport, but a sport is not necessarily a bud mutation. The logic here is simple. If a single bud on a plant gives rise to a different phenotype, the mutation that caused the change was in primordial cells that gave rise to a bud that perpetuated the mutation. It is also possible to have mutations that affect cambial tissue such that 1/2 of a plant has white leaves (or variegated) and the other half has green leaves. Many mutations are a result of infection by mycoplasma, essentially these are the viruses of the plant world. I am not an expert on mutations, but can state accurately that almost all plants are subject to them and that any clonally propagated plant will eventually throw a mutation. This is why there are nearly a dozen known “sports” of Red Delicious apple.
Persimmon is more complicated due to polyploidy. I am going to speculate so don’t take this as proven! If persimmon sex determination is a single allele on a chromosome, then a hexaploid persimmon has 6 copies of the sex allele. If all 6 are for a female plant, then the plant is female and will never produce a male flower. But if 3 are male and 3 are female, then the plant might produce a range of flowers from male to female depending on which chromosome of the 6 is active as the flower initials are formed. There are other combinations such as 4 female and 2 male or 5 female and 1 male that might produce occasional male flowers. There is no way to prove this other than to investigate the flower sex determination genes in persimmon.
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Thank you, Darrel!!!
I should probably give an example where a sport is not necessarily a bud mutation. Sweet potato variety Puerto Rico has a common mutation where the roots change from orange to more yellowish in color. This is NOT a bud mutation, but it is a sport which occurs repeatedly. Growers have to constantly select Puerto Rico plants that produce only deep orange roots because they taste much better than the yellowish version.
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Is that a viral entity, Darrel?
If you are referring to mycoplasma, yes, it is basically a plant virus. If referring to Puerto Rico sweet potatoes, the best I recall, it is caused by a genetic difference in the skin tissue vs the interior tissue of the root. Sometimes the skin tissue gets included in the cells that form the roots resulting in the yellowish color.
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Elaborating on my point from earlier. The research appended below shows that the Japanese PCNAs are closely related to each other. A cluster of varieties that includes Fuyu, Jiro, and Okugosho is distantly related to the Japanese PCA varieties; but a cluster that includes Gosho, Hana-gosho, Oo-gosho, and Yamato-gosho is more closely related to some PCAs.
Moreover, the four gosho names in the latter cluster originated in neighboring prefectures – Nara, Hyogo, and Tottori. The varieties in the former cluster come mostly from Gifu, slightly further east.
Both clusters include a variety that is evidently a good pollinator – Oku-gosho in the former (Fuyu/Jiro) cluster and Hana-gosho in the latter (Gosho) cluster. Oku-gosho and Hana-gosho have been the most widely used pollinators in Japanese and Korean breeding programs, at least until Taishu showed up.
All of this seems to suggest that Japanese PCNAs originated with the Gosho cluster as a mutant offshoot of PCAs, after which the Fuyu/Jiro cluster splintered off and interbred.
69_665.pdf (980.6 KB)
What would you cross them with?
I was just reading up on the genetics of PCNA persimmon. The Japanese varieties are based on a recessive gene that inhibits production of the tannins responsible for astringency while the Chinese PCNA’s are based on a dominant gene that amps up production of antagonists that destroy (or permanently bind) the tannins. The key information is that the chemistry involved is part of the flavonoid biopath meaning that disrupting production of proanthocyanins will also disrupt production of flavor compounds. In other words, removing the astringency via genetics may cause a huge hit against good flavor.
American varieties seem to have a different mechanism whereby some clones naturally remove the tannins but only at fruit maturity. I could speculate that the Chinese PCNA genes might be synergistic with the American genome.
What is significant is that a good persimmon genome has not yet been produced except a limited copy for a diploid persimmon. It would be nice to have a full hexaploid genome mapped and annotated to work from.
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Some questions:
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Is there a short list of readings?
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Are you sure you’ve got the Japanese story right? I thought the mutation in PCNAs involved defective storage of tannins. Unprotected by vacuoles (which are missing), the tannins are vulnerable to degradation / binding. My memory here is admittedly fuzzy.
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If #2 is remotely right, then flavor may not be at risk. PCNAs already “remove astringency by genetics” and a ripe PCNA is tasty, so non-astringency is apparently not incompatible with good flavor.
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I’d just like to jump in real quick. If you say tannins are not being carried as heavily because of an absence of vacuoles, then my question is, where are the so-called tannins at/located, now? Did they never develop or could it be possibly they were expelled in gas form, naturally and were able to do so starting much earlier than mycoplasma containing vacuoles & specifically more tannis being carried with said.
Thanks
Some of this is answered in the research available on a search for “persimmon genome”. There are genes involved in production of proanthocyanins, genes involved in storage of same, and more genes that either denature or inactivate them.
Barkslip, the best I can tell from the literature I have read, all persimmons produce proanthocyanins but some persimmons either don’t retain them or else deactivate them via other genes. This is a very common arrangement with plants to have genes to produce a compound and other genes to destroy it. For example, leaves produce chlorophyll, but in the fall when the leaves reach senescence, the tree converts the chlorophyll to other compounds and pulls some of them back into the tree for storage. The leaves turn red, orange, yellow, and eventually brown because the chlorophyll has been displaced by anthocyanins.
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I’m very satisfied with proceeding forward. Thank you, Darrel, thank you guys.
Darrel, we need genomes to advance science to make this super-easy.
I’m satisfied what I’m gonna do.
@jrd51 - incredible thread.
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Taishu a newer japanese PCNA cultivar has one added bonus: It can be eaten in a green stage a so called “Green Kaki” is quite popular in Japan. Don’t have a long enough season? Don’t worry, you get a sweet and crunchy fruit without a pucker.
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You got any recommendations on Chinese PCNA cultivars at their hardiest moment, let me know, anyone.
Thank you.
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There is only one well-known Chinese PCNA, Luo Tian Tian Shi. Moreover it’s genetics are different than the Japanese PCNAs with very uncertain implications for the flavor of children.
Among Japanese PCNAs, Ichi Ki Kei Jiro has been good here to roughly -3 to -5 so I can testify on that one. I’ve seen reports that Tam Kam and Gwang Yang are good to -5 F but I have no experience with them.
I’m not looking for Japanese. I want Chinese.
I’m sorry, thanks, though…
"Morris Burton is involved in all of the 4 varieties that were observed to produce what Martha Davis and I call non-astringent fruit. That is some of the fruits could be picked off the tree while still firm with no astringency. Those 4 varieties were L-92, L-93, L-104 and L-104A. Morris Burton is involved in all 4 of these. L-92 and L-93 are Szukis X F-100. L-104 and L-104A are F-7 X Killen (using female pollen). Female pollen is my way of identifying pollen from pistillate trees. Early Golden,
Garretson, Killen and Szukis will all occasionally put on male flowers "
It sounds like Morris Burton is a special DV indeed…
Not to derail the progress of this thread, but I have to ask, and please ELI5- is there a genetic difference between fuyu and hachiya and saijo and chinese bred fruits to the point that they are actually a different species? I always see the distinction between American and Asian persimmons, and I understand that. But this discussion of “species within species” more or less is confusing but I’m trying to follow. That is, relating to astringent vs not. I understand the gene expression and recessive vs dominant aspect, but is there something else going on? I also find sometimes that asking simple and sometimes obvious seeming questions leads to a more fruitful outcome.
What I am getting at, if I understand things correctly, is that maybe if the right unicorn DV (maybe one of those discussed by Mr Lehman in the linked thread) is used for non astringent breeding, maybe just the right genes will be expressed and maybe a fusion of the recessive Asian and DV (whether recessive or dominant) will be enough to accomplish the hardiness and non-astringent goals desired. Maybe as there are multiple mechanisms present, not all of them need to be expressed to achieve the desired outcome.
I’m no geneticist and this is just hypothesizing on my part with no evidence to back up my thoughts. You guys are way ahead of me.
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My understanding is: Different species, no. Just variants, like blondes and brunettes. There is a significant number of genetic variations, but all within a species. Variations include (1) Do tannin cells stop developing in spring? (2) Are tannins sensitive to alcohol/CO2? (3) Do seeds produce ethanol?
I’m intrigued by the stories about Morris Burton but have to wonder why this supposed non-astringency hasn’t attracted more notice before now.
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