Embryo Rescue

General Fruit Growing
#1

Disclaimer- I know very little about this topic other than the general idea of popping an embryo out of a seed, immediately placing it into media, and feeding it a concoction of sugars and other necessary nutrients to help it grow into a viable seedling. I would be most interested in experimenting with kaki/virginiana crosses using this method. Has anyone successfully performed embryo rescue? Is it extremely expensive? Do I need fancy lab equipment or can I put a plexiglass box together in my basement with a walmart shop light and succeed?

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#2

I’m interested in learning about the various reasons for resorting to this intervention. Perhaps someone can provide a list circumstances that cause horticulturists to choose embryo rescue.

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#3

  1. I’m 34 and not getting younger

  2. kaki/virginiana will generally not produce viable seeds when crossed without embryo rescue, to my knowledge.

  3. This appears to be the most expedited pathway available to the breeding results I’d be interested in. Notice I did not say the easiest route, but I’m not getting any younger. It’s all a cost benefit equation I’m trying to figure out.

#4

Ok, but maybe some of the biologists here can give us some background information that would benefit us all.

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#5

I can’t answer any of the questions except “has anybody done it?” My understanding is that while Jerry Lehman crossed Josephine x Taishu to produce JT-02, an embryo rescue was performed in Japan.

#6

Yes, this is why I am hesitant to research further because I don’t want to waste time if thousands of dollars (millions?) is required for lab equipment.

#7

Have you seen this paper? The full text is paywalled for me, but the abstract gives a little bit of information about how they did it.

https://www.sciencedirect.com/science/article/abs/pii/S0304423805003298?via%3Dihub
Fruit set and embryo rescue in crosses using parthenocarpic ‘Mopanshi’ persimmon, by P. Leng and H. Yamamura, Scientia Horticulturae Volume 107, Issue 4, 27 February 2006, Pages 332-336

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#8

Leng and Yamamura 2006 - Fruit Set and Embryo Rescue.pdf (198.7 KB)

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#9

Cool, thanks!

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#10

I believe he meant if any members here have successfully performed embryo rescue.

#11

@disc4tw

So Yeng and Yamamura were motivated by Immature embryos.

Did Lehman have the same problem, or did he just have a few seeds and wanted to ensure one of them sprouted?

I am guessing that Lehman sent his to Japan because the price was right; i.e. no cost in exchange for access to material for tissue propagation.

#12

Here is how I see it. Jerry gave Us JT-02 and Ukrainian gave Us Rossyanka and both are F1 50% Kaki/50% DV. The Ukrainian kept on crossing Rossyanka male to the 4th generation now to get Dar Sofiyivky. So far JT-02 crossed one time with Rossyanka male to get JBT-06 offspring. I am more interested in continuing crossing the offsprings that we got thus far to get a more cold hardy fruit for a true Z5 than trying to start over with embryo rescue. I can take a progeny of Rossyanka 400-5 with cold hardy of -33F at my place and can cross with any female Kaki or DV to get a cold hardy hybrid persimmon without the needs for embryo rescue

Tony

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#13

@tonyOmahaz5
It’s not clear to me that embryo rescue is necessary for every batch of kaki x viginiana seeds. Perhaps those interested in a new cross should first learn how to examine embryos – likely a no-cost endeavor. Once you have that skill down you can start making crosses and examining what you have. If you then decide e-rescue is needed, then I believe the biology department at any U.S. state land-grant college has all the equipment you need.

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#14

Well, sure, I knew that was a possibility. But that’s not what he wrote. He could have meant “is this merely hypothetical?” And I didn’t want to not answer based on my assumption.

#15

Tony – Great overview. I’m very sympathetic. But if the primary goal is better cold hardiness, wouldn’t it be preferable to cross the existing (female) hybrid with a Virginiana male?

#16

I would be very happy to find out this is true. That’s part of the fun and experimenting!

#17

I have not done embryo rescue. There is a lot of information on using it for doing wide crosses in the genus lilium (true lilies). Also a fair amount of the information is geared to hobbyists like yourself that would be doing the rescues at their homes. The amount of equipment is modest and so is the expense if you’re willing to accept some failures. It requires a fair amount of dedication and time commitment but it is doable. I would do a search for “embryo rescue lilies”, “embryo rescue lilium” and see what you find. I have read articles on how to do embryo rescue on lilies in a home environment so I know they exist.

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#18

If I crossed JT-02 Hardy to -26F with a pure DV male then I will have an offspring with smaller fruits from the DV lineage and only 25% Kaki and 75% D. Virginiana with good cold hardy offspring. But if I crossed JT-02 with Rossyanka opened pollinated male offspring 400-5 hardy to -33F in 2019 here in Omaha with larger fruit from Rossyanka parentage that Jerry Lehman sent to me a few years before his passing then the new offspring will have larger fruits and more Kaki percentage than straight DV male(small fruit size traits). In addition, it will inherited the cold hardy traits of both parents which survived the low temp here in Omaha JT-02-26F and 400-5 -33F.

Tony

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#19

@tonyOmahaz5
What are the prospects for hobbiests in the U.S. of obtaining any of the foreign hybrids for further breeding in the next 10 years?

#20

I think you missed my point. I didn’t mention JT-02 at all. . . .

You wrote, << I can take a progeny of Rossyanka 400-5 with cold hardy of -33F at my place and can cross with any female Kaki or DV to get a cold hardy hybrid persimmon without the needs for embryo rescue. >>

So you are talking male Rosseyanka progeny x female Kaki or DV.

My question is why not switch the sexes – Cross some male DV x any of the various female Rosseyanka progeny (e.g., Dar Sophievki, the Gora series, Kassandra, as well as Rosseyanka 400-5). Using a DV male would seem to give you tremendous variety and flexibility on the [female] hybrid side.

I get the risk that the result would be a smaller fruit. But you presented the prospect of crossing with “any female kaki or DV” so I didn’t think DV parentage was off the table. And the Ukrainians have already shown that DV parentage does not condemn a hybrid to small size.

I also get the attraction of starting with a parent that is both very cold hardy and very large fruited. But maybe there are other negatives such as late ripening.

So my thought was that a DV male could be crossed with a variety of Rossyanka progeny females. Cold hardiness of the offspring, which is your priority, would most likely be high. Other attributes such as size, earliness, flavor, loss of astringency could be sorted out in the selection of preferred seedlings. Many of these traits are quantitative, so maybe they can be optimized in successive generations – once cold hardiness is nailed.

p.s. Richard’s question re the availability of hybrid varieties may highlight the limiting factor.

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