Doubled haploids

[zif]

Several points: at the haploid stage, they would definitely be weaker.
At the double haploid stage, I said I accept they work as diploids, but still have less adaptability due to fewer gene choices.

The only reason to make DH P1 plants is to produce....., Oh shit you're right, the whole purpose is to only produce one generation of plants. What a fuckin pointless exercise. Then what lol.

I was thinking that the line would be created in order to be true breeding for all traits for a few gens. I was thinking that these seeds would then be sold as an ingredient for others to create their own recipe. But no, they're trying to make conformist weed. What a total waste of time. It leads nowhere. Completely useless tech.

Maybe weaker - assuming that the plant will tolerate staying haploid in the first place. But maybe not. It's not something that the theory (or, generally, empirical data) demands.

DH plants are interesting to me because they're the least resource-intensive approach to making F1s. The slight biotech overhead involved, especially in anther culture, is pretty minor - on par with growing mushrooms from spores. As with any tool, the usefulness isn't really dictated by the tool, but by how it is used.

Maybe it's just me, but I think great breeders would be even better if they could easily make true F1 hybrids. After all, then the description on the pack would stand a fighting chance of describing most, if not all, of the plants it can produce. Worrying that there is too little variability, too much predictability, or too many very reliable packs of seeds on the market seems to have it backwards.

As for whether it's conformist weed, that strikes me as down to selection.

 

[GMT]

I can see that the seed maker, (applies to far more than just the breeders list), may consider it the chance to sell reliable generations to demanding customers. They may believe it will increase sales, as knock offs would be noticeably different. But to be honest, now they sell packs of 10 seeds, sometimes two packs to one customer. But why would the customer want 20 seeds, when they are the same? Now the customer only wants one seed. Do prices shoot through the roof or does this tech put all smaller scale producers out of business?
Besides, there's far more interesting tech being developed, that will revolutionise and stagnate the seed biz for decades when it kicks in.

 

[GMT]

This is where that goes,
Reverse breeding in Arabidopsis thaliana generates homozygous parental lines from a heterozygous plant.
Wijnker, E., van Dun, K., de Snoo, C. B., Lelivelt, C. L. C., Keurentjes, J. J. B., Naharudin, N. S., Dirks, R.
Nature Genetics, 44(4), 467–470.(2012).
doi:10.1038/ng.2203
Traditionally, hybrid seeds are produced by crossing selected inbred lines. Here we provide a proof of concept for reverse breeding, a new approach that simplifies meiosis such that homozygous parental lines can be generated from a vigorous hybrid individual. We silenced DMC1, which encodes the meiotic recombination protein DISRUPTED MEIOTIC cDNA1, in hybrids of A. thaliana, so that non-recombined parental chromosomes segregate during meiosis. We then converted the resulting gametes into adult haploid plants, and subsequently into homozygous diploids, so that each contained half the genome of the original hybrid. From 36 homozygous lines, we selected 3 (out of 6) complementing parental pairs that allowed us to recreate the original hybrid by intercrossing. In addition, this approach resulted in a complete set of chromosome-substitution lines. Our method allows the selection of a single choice offspring from a segregating population and preservation of its heterozygous genotype by generating homozygous founder lines.


But I think this is what will win the day.

Gene discovered crucial to making crop plants produce clonal seeds
PhysOrg Jan 6, 2022
https://phys.org/pdf560694578.pdf
Researchers from KeyGene and Wageningen University & Research (WUR), in collaboration with colleagues from Japan and New Zealand, have discovered a gene that will make it possible to produce seeds from crops that are genetically identical to the mother plant and that do not need pollination. This phenomenon, called apomixis, enables plants with a desirable combination of traits to produce many offspring with the same desirable combination of genes as the mother plant. Together with researchers from the Japanese breeding company Takii and New Zealand's Plant & Food Research and Lincoln University, the KeyGene and WUR researchers explain in Nature Genetics how the gene works and the way it influenced the work of the 'father of genetics' Gregor Mendel. The discovery is expected to lead to major innovations in plant breeding over the coming years. The gene found has been given the name PAR, shortened from parthenogenesis, the process whereby egg cells grow into plant embryos without fertilization of the egg cells. The discovery marks a definitive breakthrough and crowns the research team's work that started at KeyGene over 15 years ago.

 

[zif]

I can see that the seed maker, (applies to far more than just the breeders list), may consider it the chance to sell reliable generations to demanding customers. They may believe it will increase sales, as knock offs would be noticeably different. But to be honest, now they sell packs of 10 seeds, sometimes two packs to one customer. But why would the customer want 20 seeds, when they are the same? Now the customer only wants one seed. Do prices shoot through the roof or does this tech put all smaller scale producers out of business?
Besides, there's far more interesting tech being developed, that will revolutionise and stagnate the seed biz for decades when it kicks in.

Selling single seeds wouldn't be so bad if every one of them was (virtually) identical. It'd also be much easier to write good descriptions for seed packs if seed makers were not averaging over a little (or a lot) of variation.

This is where that goes,
Reverse breeding in Arabidopsis thaliana generates homozygous parental lines from a heterozygous plant.
Wijnker, E., van Dun, K., de Snoo, C. B., Lelivelt, C. L. C., Keurentjes, J. J. B., Naharudin, N. S., Dirks, R.
Nature Genetics, 44(4), 467–470.(2012).
doi:10.1038/ng.2203
Traditionally, hybrid seeds are produced by crossing selected inbred lines. Here we provide a proof of concept for reverse breeding, a new approach that simplifies meiosis such that homozygous parental lines can be generated from a vigorous hybrid individual. We silenced DMC1, which encodes the meiotic recombination protein DISRUPTED MEIOTIC cDNA1, in hybrids of A. thaliana, so that non-recombined parental chromosomes segregate during meiosis. We then converted the resulting gametes into adult haploid plants, and subsequently into homozygous diploids, so that each contained half the genome of the original hybrid. From 36 homozygous lines, we selected 3 (out of 6) complementing parental pairs that allowed us to recreate the original hybrid by intercrossing. In addition, this approach resulted in a complete set of chromosome-substitution lines. Our method allows the selection of a single choice offspring from a segregating population and preservation of its heterozygous genotype by generating homozygous founder lines.

That's very neat - but does the same thing as a DH, and with the added challenge of requiring the biotech chops to silence a gene (if it, or a close analog, exists in Cannabis). The inducers I referenced pages back have the same issue, of course. But anther culture is the obvious small-scale target for DH production, and it's well within reach of anyone with any experience with sterile technique.

But I think this is what will win the day.

Gene discovered crucial to making crop plants produce clonal seeds
PhysOrg Jan 6, 2022
https://phys.org/pdf560694578.pdf
Researchers from KeyGene and Wageningen University & Research (WUR), in collaboration with colleagues from Japan and New Zealand, have discovered a gene that will make it possible to produce seeds from crops that are genetically identical to the mother plant and that do not need pollination. This phenomenon, called apomixis, enables plants with a desirable combination of traits to produce many offspring with the same desirable combination of genes as the mother plant. Together with researchers from the Japanese breeding company Takii and New Zealand's Plant & Food Research and Lincoln University, the KeyGene and WUR researchers explain in Nature Genetics how the gene works and the way it influenced the work of the 'father of genetics' Gregor Mendel. The discovery is expected to lead to major innovations in plant breeding over the coming years. The gene found has been given the name PAR, shortened from parthenogenesis, the process whereby egg cells grow into plant embryos without fertilization of the egg cells. The discovery marks a definitive breakthrough and crowns the research team's work that started at KeyGene over 15 years ago.

Agree, that's quite neat. But serves a different end - producing 'clonal' seed - rather than making improved varieties. FWIW, it would also require editing the Cannabis genome.

DHs caught my interest - a couple of decades ago - because they will facilitate the generation of new hybrids with exceptional vigor and uniformity, while requiring very low live plant counts. They are, from a traditional breeding standpoint, pretty hard to beat.

 

[GMT]

Before any of it is worth while, first we need to decide which genes are : desirable, undesirable and irrelevant. Then in what quantities. Once we know what all the genes are doing, and their relevance to each other, then we can make leaps forward in breeding. But until then, any cross is still a "suck it and see" deal. Even if there are 1000 identical copies.
At least with clonal seeds, you know the end result before you start. But this is what I think will stagnate any advances being made beyond it, for a long time. It'll suck the cash out of other research because it's guaranteed, profitable seeds.

 

[Moe.Red]

Subscribed. I’d like to head back to the start of the thread before I comment, but this is some very cool discussion ya got going.

I currently do tissue culture on a personal level and I know I am missing out on a lot of potential based on lack of knowledge you folks have.

 

[GMT]

@Tom Hill , peruse if bored, some interesting insights on future tech.

 

[CreeperStipule]

Fully agree with Zif that DH's are more useful, the thief was into the clonal seeds years back.

 

[GMT]

Diff tech I believe. I'm sure that was artificial seeds, using tissue culture and some water soluble gel wrapping the agar plus T.C. I don't think it's actually available for cannabis yet.

 

[Ecor1]

Apomixis Cannabis

 

[Tom Hill]

Where are we? The difference between DH breeding and reverse breeding is the latter halts crossovers in vitro. My uncle's bro does the latter at uc Davis with many plants it's a matter of protocol.

 

[Ecor1]

Where are we? The difference between DH breeding and reverse breeding is the latter halts crossovers in vitro. My uncle's bro does the latter at uc Davis with many plants it's a matter of protocol.

Have they done any work with dicots in using Apomixis? Doing this with rice and dandelion.

 

[Ecor1]

UC Has been cranking out some serious work.

 

[Ecor1]

Found an Apomixis gene site on male pollen in hops. Thinking that the haploid male pollen is a potential candidate?