Jujubes- Our New Adventure

Would you prune this damage on a young jujubes trunk? The tree has a very nice structure above it

Thanks

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Personally, I wouldn’t. Jujubes are not prone to disease and they usually grow up stout and sturdy so I would just let it heal naturally and fill in. Others may have another opinion.

I’m not a big pruner anyway and I especially like my jujubes in their natural state. That being said sometimes as a growing tree they need pruning. Let me share with you a key to jujube growth and training. This will make a big difference later to control growth you don’t want and promote growth you want.

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I had a similar or worse injury on a young Honey Jar that had been almost broken in half. It was bad enough that I was debating between topping it, or possibly even drilling in a stainless steel screw. Here’s a pic:

I ended up taking no action and just waiting to see what would happen. The next pic shows the same tree about a month or so into the growing season. You can see that it rapidly started to form woundwood around the injury:

By the end of that year, the injury was pretty much entirely enclosed and is only noticeable because the bark on the woundwood looks different. Although I am not sure about woundwood in jujubes, in most trees, the woundwood is actually stronger than the normal wood, so the site of the injury may be structurally stronger than the rest of the tree.

So I agree with @k8tpayaso – I think you’ll be fine with just letting it heal. Jujubes are tough.

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That’s definitely a worse injury, and your tree healed beautifully.

Thank you marten!

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Sorry it has taken me a while, but I didn’t forget your comment and have been meaning to go back to the paper for more detail.

I just went through it again and the paper touches on the tools that have historically been used in the analysis of jujubes:

For the management of jujube germplasm, a variety of molecular markers have been used

1.) “amplified fragment length polymorphism”- when I looked it up on Wikipedia, it wasn’t the easiest to read description. But, it seemed to say that it would extract and examine segments. I could have easily missed it, but didn’t see anything referring to “length”, though it is in the name itself.

The wiki page did say:

The AFLP technology has been used in criminal and paternity tests, also to determine slight differences within populations, and in linkage studies to generate maps for quantitative trait locus (QTL) analysis.

If it isn’t an accurate method, I would hope it isn’t being used in criminal trials. :slight_smile:

2.) simple sequence repeats (SSRs)- sounds like this looks for repeating patterns in the DNA.

3.) SNPs- Single Nucleotide Polymorphisms. Differences in a single DNA building block (like a C vs a T)

This study in particular, looks to have used #3:

The 159 SNPs, previously validated by Song et al. (2021) along with their corresponding flanking sequences were submitted to LGC for a KASPar assay design. The KASP chemistry (Biosearch Technologies) was used for genotyping. The KASParTM Genotyping System is a competitive allele-specificdualfluorescence resonance energy transfer (FRET)-based technology for SNP genotyping (Cuppen 2007). The genotyping was conducted following an in-house protocol of LGC. The resulting genotypic data were returned as .csv files and analyzed using an SNP marker analysis software (SNP Viewer version 1.99; Biosearch Technologies).

Pairwise multilocus matching across all jujube cultivars was performed to identify duplicate samples using the SNP data. Jujube samples that perfectly matched across all genotyped SNP loci were referred to as duplicates/same cultivar or clones.

Looks like they took the the 159 SNPs and got rid of 12 of them where there wasn’t sufficient variation:

Of 159 SNPs used to genotype the jujube samples, a total of 147 genome-wide SNP markers were retained for analysis. Data filtering was done to remove SNPs with minor allele frequency <0.05.

I thought it was interesting that there were several which matched on 146 of 147 (Weeping Li, Allentown, and Express Gee almost matching Li and a few others were off in other groups by 1), but none that matched on a few less than that (ie no 145/147 or 144/147). Everything was either exact, off by 1, or off by a lot.

A total of 116 accessions were classified into 23 synonymous groups of the 177 analyzed germplasm accessions (Table 2). There were 2 to 24 accessions in each synonymous group. Cultivars Weeping Li, Allentown, and Express Gee had matching SNP profiles at all but one locus and thus, were almost identical to the first synonymous group in Table 2. The samples that differed by one SNP locus were also considered synonymous, as this difference was attributed to genotyping errors (Supplemental Fig. 1) (Akpertey et al. 2021; Waits and Paetkau 2005; Zhang et al. 2006). We did not report any samples that differed by only a few loci (more than one).

It does mention that there are some cultivars where they see significant differences (such as some of the Jinsi series), yet they have the same SNPs. The mention of “mutations in these clones”, seems to indicate that any which are grouped together could still be branch sports.

Results demonstrated significant morphological differences within genetically identical cultivars in the Jinsi group, indicating phenotypic variation resulting from mutations in these clones.

I looked through and only found one mention of PCR, in the historical overview area. But, I have only a vague understanding of part of the paper, particularly that which discusses those historic methods. The comparisons from this paper seem to have been done on individual locations, rather than lengths (though I see discussion of flanking sequences, which I think is how they located the individual locations). I’d be interested in any additional insights you have based on these details.

Original paper:

@BobVance
You can rest easy that “molecular markers” are not used in criminal trials. There are plenty of defense experts that would have the case thrown out.

Molecular markers are darlings of horticultural genomists and the lab companies that make the assay equipment. There’s a 30-year history of it since PCR assay was discovered in Berkeley CA circa 1988.

The basic functionality is to anneal “markers” with cell samples of an organism. The robotic system will return short amino acid segments produced by the PCR reaction. In horticultural genomics, the lengths of the segments are estimated. These lengths are used as a value to represent the amino acid segment contents. The contents are not examined except in the design of markers.

As geneticist J. Coyne pointed out 25 years ago, this is akin to phrenology. There are many reasons – for example segments are returned when markers aren’t present, segments are returned that don’t contain the marker targets, and segments are returned that only partially match the markers.

It gets worse. The mathematical analysis of the relationships between the lengths fails both statistics 101 and pre-calculus. Further, the manufacturers of the PCR assay equipment provide the horticulturists with software that contains these errors.

For their part, the horticulturists just shrug and publish their papers in horticulture genomic echo chambers like the JASHS.

Are you sure that is what the paper used? I seems to be talking about individual nucleotide pairs, rather than lengths. I get that it can be hard to locate an individual location. And it seems that there could be some error, given that some of the samples were off by 1. But it seems that looking at such a localized segment would be much more accurate than estimating segment lengths. If there was such a high error rate, I would think there would be samples that differed by 2, 3, 4 nucleotide pairs as well, but the study didn’t find any. Just 100% match, off by 1, and off by a lot (a different variety).

That may be true now (I didn’t do any research on current methodology), but it looks like PCR was used back in the 90’s. Your mention of geneticist J. Coyne led to me reading about him online (interesting guy) and it seems that he was one of the experts consulted in the OJ Simpson case. In that case PCR was used to test the blood on the glove. Coyne’s objection was on the error rate, both in terms of the labs handling procedures and because only 49 of 50 samples matched (not a 1 in 6 billion chance of error that they claimed). Interesting to note that he later said OJ was “guilty as hell” and he wouldn’t be acting as an expert witness in the future.

I did a brief check for his commentary on PCR, but didn’t locate anything. But there were 13 pages of search results and I only skimmed the first few.

Absolutely. I publish papers in the subject.

PCR is used for many things. There are several assay methods. I am criticizing the one used in horticultural genomics.

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Question for you guys:

I’m about to plant a contorted jujube in my front yard, and I’m wondering if it will set fruit well without a pollinator.

I have Li, Honey Jar, and Sugarcane far away, like 200ft with some trees in between.

Thank you

Has anyone else had issue with Chico being bitter? I have 2 chicos and they are our most productive variety but they are the only variety that nobody in our household eats because they are so bland and bitter.

Per Prof Yao’s pollination study, So is not self-fertile. Of the 3 you listed Sugar Cane would be the best pollinator to graft onto the So, as they are both AM bloomers, while Li and HJ are PM. My understanding is that there is some overlap between AM/PM bloomers, but it is most effective to have one of the same type around. I have lots of both., so it hasn’t really been a worry for me.

I don’t think I’ve had any bitter (or particularly productive) Chico. Sugar Cane is the one that sometimes has a bit of a bitter aftertaste for some people.

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How far does pollination reach? Would one tree pollinate another with several trees in between at, let’s say, 250ft of distance?

Thank you ! I didn’t realize I could also just graft a branch of my Sugarcane into a Contorted

No idea. I googled for fruit trees in general and the answers ranged from 50 to 500ft. Most were around 100ft. I suspect that bees may travel further than that , but you don’t have any guarantees that they will hit both trees. And jujube are often pollinated by smaller insects, so they may not go as far.

All jujubes can become multi-grafts. I have a Contorted with over a dozen varieties grafted on. They make good multi-grafts, as they tend to grow a bit lower and wider than most jujubes.

In your case, grafting on a few buds of Sugar Cane is fairly easy and without much downside. If it doesn’t work, you can always try again next year, since you can cut the wood for yourself. Jujube grafting works similarly to other fruit grafting, such as apples. I find cleft grafts of roughly pencil-thick wood to be pretty easy, but other also like bark grafts.

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I saw ants on mine, likely due to the interesting smell of the blooms. Perhaps ants pollinate in a similar way to dragonfruit?

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I planted 2 bare roots couple of years ago-Honey jar and sugarcane. Honey jar grows much slower than sugarcane. I am in Va, zone 7b. Same experience as you for honey jar…kinda glad its not something I did. The tree is surrounded bg many rugosa roses so thought there might be root competition affecting HJ vigor.

I made a mistake of grafting HJ on the same root as another variety. I just could not get the HJ to grow well and I had to eventually remove the other variety. So more evidence of how slow it is.

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Did you Honeyjar speed up growth when you got rid of the parasite? :slight_smile:

I got my Honeyjar from Grow Organic today, right when our weather turned to snowy.

Looks like a little over 3’ of trunk, cut just enough to fit in box, and about 1’ of root. Overall pretty good.

Now I’ve got to figure out where to put it along with an Autumn Beauty

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Looks good Murky. My new addition will hopefully be shipped soon, a Contorted (So) from Starkbros. It was $43 with shipping so I couldn’t pass

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For a year it just moped, but it is finally taking off. Its about 15’ tall now.

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