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Cubing - A myth by Chimera

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Cubing - A myth by Chimera

Texas Kid 110 Replies 110,230 Views
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#84
no the bros grimm story is not bullshit. i know a guy who grew test seeds for them, another guy who has original grimm stock still. princess, genius, almost all of them. If I can find the post i will link it or copy and paste it its off the old overgrow files.
 
#85
caveman4.20 said:
I got a sour fruity pebble pheno makes your heart race like c99
Click to expand...
my keeper alien rock candy is the same way, super intense. great for bike rides or working out. even the shatter made from it is speedy. first time ive had weed that did that.
 
#88
Interesting read Chimera.

Do you think Soul got lucky with C99?

In my experience C99 seeds produced consistent results when grown by different growers under different growing conditions.

I was very good friends with Sly and he shared all of BG's breeding stock with me except princess. I know that in the earlier days Soul did share some Princess cuts with a select group of friends. But Sly told me that Soul no longer wanted to give out anymore cuts. However Sly did share a big fat sack of Princess buds with me.

So from my experience having sampled c99 from multiple growers and Princess straight from the source I can say Soul achieved what he claimed. That's not to say I challenge plant breeding facts as you presented them. I have always had a great deal of respect for your knowledge of Botany.


On a side note:

I was always a bigger fan of Apollo13 , Apollo 11 and Genius. I always thought it was really cool of Soul to share Genius with the community directly and indirectly. Don't know of any other breeders with such a wildly successful strain who is willing to share parental stock.
 
#89
Awesome read thru the first 49 posts thanks for posting this thread man up to this point ive always quickly been bored reading the breeding material because of all the montonous use of big words and Capital and Lowercase letters but things where explained here in a more learning friendly way like in science class when learning science was fun when i was a kid. I will get back to this when i have time to chill again. Apprechiate the knowledge.
Peace
 
#94
What's the best method depends on the specific goals. Back crossing populations (what cubing basically is) is not some new technique, it's been documented nearly 50 years ago already and a very common method in modern plant breeding. It has its specific purposes which is kind of what I wanted to show. Cubing is still in a way "best to best and cull the rest" with the difference that one of those "best" is the same homozygous plant every generation and the other best are multiple plants. Instead of selecting genotypes you manipulate the gene frequency. Instead of selecting AA, you increase the number of A genes in a population, and hence the chance of two AA's being combined instead of Aa or aa.

"Best to best and cull the rest" is population breeding, also known as recurrent selection breeding (you hunt for and select the best phenos every run). The goal there is to increase uniformity while still retaining a wide heterozygous gene pool (i.e. prevent inbreeding depression and increase the survival chance of the population). "Best to best and cull the rest" is what farmers have done for thousands of years. It's what the pioneers had to do and still applies well to acclimatizing and beefing up land races or an existing strain. It's basically what happens in nature too, the weak and ugly don't get to mate.

While population breeding reduces phenotype variation to the better ones and can lead to a strain uniform enough for growing, for a true bred IBL one needs to go a few steps further, and reduce genotype variation too.

Since about a hundred years ago plant we (mankind) use "modern plant breeding" techniques (partly based on Mendel's work). I can't put this any other way than: that's what breeding is about for nearly a hundred years. The real F1 hybrids and true bred homozygous lines used to create those are a result of that, fruits, veggies, ornamental plants, cows and pigs. Unlike heirlooms. Cannabis industry is a different story.

Please don't get me wrong, I'm not saying the old brute force methods don't work or can't lead to excellent results. Population breeding will by itself however not lead to a true homozygous variety (by genotype and not just phenotype). I'll spare you the punnet examples, but it's related to the Hardy Weinberg principle, and is natures way of ensuring variation. To create a "new" stable homozygous strain/variety, a stable "line" would have to be created from the population by selecting individual plants, or back crossing to an already stable line. One is not supposed to stabilize an F1 hybrid but their parents. A proper F1 hybrid has no pheno variation. In reality, in the cannabis industry, they often do, because people don't start out with homozygous IBLs.

To create true F1 hybrids (that actually express heterosis aka hybrid vigor) two different stable homozygous lines are needed. To create a stable homozygous line through sibling mating you need to lock in traits, as in breed them true, as in make them homozygous. To have all homozygous offspring (making it a truebred) you need to cross homozygous with homozygous. This means having to select two plants with genotype AA instead of one or two Aa for example, which in case of complete dominance will both be the same pheno type. This requires really getting to know your plants as in how their traits inherit. This in turn allows you to predict the outcome of crossing two plants.

Obviously that is a lot of work, it requires what is called 'intense' selection and usually involves test crosses just to see how certain traits inherit. Trying to breed one or more traits true every generation. Cubing 'can' be a sort of brute force method to achieve similar results.

When you start breeding it's a bit of a chicken and egg thing, whether you create an F1 hybrid or go for backcrossing a new variety, homozygous IBLs are sort of mandatory. You can either use someone else's, or create your own. Cubing is a feasible way to create one with a relatively small amount of plants. Create another one and you can create a proper F1 hybrid.

I've had similar discussions in which this came up before so I will add up front: no, this is not just some academic theory, in fact, it's what many breeders who never even heard of Mendel already intuitively partly do. Although there are genes and traits that don't follow Mendel's "simple rules of inheritance", as in there are always exceptions, modern plant breeding is as tried and true as it gets.

To sum it up without punnet examples:

Back crossing to save genes in seed form.
- Backcross to a recurrent parent to end up with seeds that have 94% or more of the GENES of the recurrent parent, but not necessarily the GENOTYPES. For example to save the genes of a clone-only strain in seed form. The main (valid) reason for a clone-only strain however is that it's heterozygous and you don't have the parents to recreate it. This method of back crossing will not automatically lead to breeding traits true, as in homozygous, and it will still have genotype and some phenotype variety for the heterozygous genotypes that are in the recurrent parent (similar to the result of selfing an F1, but per trait). No matter how often you cross back. This method is common in the cannabis industry. It can lead to stable for growing (not a lot of pheno variation) but not necessarily stable for breeding (that goes for "best to best and cull the rest too). Some images to illustrate what happens:

Back crossing a specific trait into an existing line
- Backcross to a recurrent parent to end up with seeds that look most like that recurrent parent but with a trait of the donor parent. In this case you backcross one or more traits from a clone-only (or special pheno you found) to an IBL / stable line. So you backcross the clone-only trait to the IBL instead of backcrossing to the clone-only. This is most applicable when the clone only has just one or few special traits of interest, (similar to the example in the link in my first post above). Auto genes is a good example, but also if you find a special pheno in a bag of land race seeds this is more effective than trying to acclimatize and beef up the land race (for which large population breeding would be more suitable). I have no idea how many cannabis breeders use this method, but it's the common method of backcrossing outside the cannabis industry. If you want to "borrow" a trait from another strain (PM resistance for example), you don't actually want mix the two strains as typical in cross and sibling mating but breed that trait and as little of the rest of the genes into the other strain.

Back crossing as in cubing a population.
- In short, when you back cross a population (in this context simply meaning more than a couple of plants) to a recurrent parent, the offspring (from those plants combined) will become more homozygous for all traits that are homozygous in the recurring parent. That's why it's important to back cross to a homozygous plant, instead of for example an F1 clone, but the key part is to use multiple plants from the offspring to cross back to the recurrent parent. For example, if the recurrent parent is a male, grow out 30 females, pollinate a small bud on all, get the seeds from the best ones (obviously those that show the desired traits most prominently), let's say 10 plants, pick 30 females from that, and pollinate with the same male again. The more plants (and the more seeds you pick from each), the less generations it will take to reach that point of being 90+% homozygous. Instead of using 1 male and many females, you could use 1 female and many males (and simply mix the pollen before pollinating that recurrent female). Downside is you get less bud, upside is you can cramp a LOT of males in a small space.

Essentially both the first and third method are about manipulating the gene frequency, but unlike the first, the third method (cross multiple plants from the offspring back to a homozygous plant) will increase the desired genotype frequency. The third still "also" increases the gene frequency (especially if you select out the once with the undesired traits, like the easy to spot recessive aa when AA is desired) which in turn increases the chances of ending up with homozygous alleles.
 
#95
I was going through my own examples in some previous posts above and noticed I made a major mistake. Specifically I switched dominant/recessive and donor/parent in both the breeding in the dominant and recessive trait examples. Rendering the rest of it invalid. The basic principles above still apply but the examples were rather long so I asked Seamaiden to remove them (thanks!).

I will keep it shorter this time:

Cubing is not a myth, some supposed outcomes of backcrossing are.

In addition to using it for specific purposes depending on what you got to work with (the three above), you can't get achieve those three goals 'combined'. For example, you can't backcross a trait into a variety AND make it homozygous for that trait by backcrossing along. You can't save the genes of an elite cut from a hybrid AND at the same time make it homozygous by backcrossing alone.

The goal of the Grimm bros with c99 was not to backcross a specific trait into another variety. They sort of went for the first example in my post above, and ended up getting results more like the third example.

I made the same mistake as in the post quoted by the op of this thread, in my examples that is. Backcrossing a trait into another variety is not to be mixed with the goal of cubing a la c99.

Whether the donor trait is recessive or dominant it requires both selection and additonal steps to get at 100% uniformity for that trait, and even more if it needs to be bred true. http://passel.unl.edu/pages/animation.php?a=BXbreed.swf&b=990818773

That's irrelevant for cubing as in backcrossing a population to make it as homozygous as the recurrent parent.

Cubing example: (H just being an example, applies to all others too).

Step1– Recurrent Parent [HH] × Donor Parent [hh] = [HHx hh] = F1 Hybrid generation [all Hh]

Step 2 – Cross the best of those F1 (Hh) plants to the recurrent parent [HH]. The generation produced is denoted BC1. [50%HH, 50%Hh, all same phenotype.]

Step 3 – Select plants from BC1 and cross with the recurrent parent; the resulting generation is denoted BC2. [take for example 8 males from BC1. Throw all the BC2 seeds you get from pollinating the recurrent parent together on a pile. Half of it will be HHxHH, half will be HHxHh, which means of 75% of the pile is HH and 25% is Hh. ]

Step 4 – Select plants from BC2 and hybridize with the recurrent parent; the resulting generation is denoted BC3. [select any 8 males from the mixed BC2 pile. 75% of the BC3 will be HHxHH and 25% will be HHxHh, so you get 87.5% HH in the mixed BC3 pile]

Step 5 – Grab 8 males again from BC3 and hybridize with the recurrent parent; the resulting generation is denoted BC4. As you probably guessed by now, the resulting pile of seeds will have 94% HH.

Those percentage are similar to P.50, P.75, P.88 (as in the Cindy example) but represent something different. Those P.xx refer simply to how much of Princess' genes are theoretically in the back cross, like so:

Princess Clone
venus_symbol.svg.png
x (SSxJH/?
20px-Gender_Male.svg.png
) = P.50 (50% Princess)
Princess Clone
venus_symbol.svg.png
x P.50
20px-Gender_Male.svg.png
= P.75 (75% Princess)
Princess Clone
venus_symbol.svg.png
x P.75
20px-Gender_Male.svg.png
= P.88 (87.5% Princess)
Princess Clone
venus_symbol.svg.png
x P.88
20px-Gender_Male.svg.png
= P.99 AKA Cinderella 99 (94% Princess)

Chimera refers to those percentages in the same context, i.e. how much of the genes of the recurrent parent are in the backcross, which indeed doesn't mean they actually express those genetics in the same way as the recurrent parent as that depends on the genotypes. But once you start using a lot of males (or females) to cross back to the recurrent parent the percentage of homozygous/truebred genotypes/traits increases in the same way in the resulting "combined" offspring. Both a homozygous (especially for the traits that matter) recurrent parent and using multiple plants from the backcross generations are required.
 
#97
imho if you want the best out of seed..you do not "breed for stability"..because that is what you will get

all the best f1's of ie.1989[hzx nl5, durban,g13/hp, bubblegum] were awesome as f1's

now they are interesting names that do not give the stratospheric mood altering amendments

that they did as f1's

also cubing is interesting but will not even give you a stabilized bunch o beans

c99 is a prime example..

sorry .. no science from me[notascientist]...i can only comment on what i observe hands on
 
#98
km1 said:
imho if you want the best out of seed..you do not "breed for stability"..because that is what you will get

all the best f1's of ie.1989[hzx nl5, durban,g13/hp, bubblegum] were awesome as f1's
Click to expand...
And like all the best F1s for most plants cultivated by mankind are the results of crossing inbred lines. If more people would focus on creating (and possibly even trading) more stable lines we'd get more of those great F1s. Typical chicken egg situation. I agree stability (genetically homozygous) should usually not be the end goal, instead do it to create parents for an F1 hybrid. The whole point and benefits of an F1 are the result of crossing two stable inbred lines.

Many growers want some uniformity in the plants from seeds and they should match the promoted description. Without breeding for stability there are only pheno hunt packs, which is great if your looking for a keeper to clone or looking for something out of the ordinary. If that's the goal I highly recommend chucking some classics together and have a blast.

Indeed cubing by itself is not neccesarily a shortcut to stability. Cubing a population to a stable (homozygous) plant however does makes the population more stable every backcross generation.
 
#99
I don't doubt Mr soul used the technique as he described what is off in the c99 story is the results he describes. Much better examples of what back crossing actually does have been described in this thread. Soul claiming c99 "Theoretically, this will be a stable, true-breeding seed line from which all females are replicas of the original." on his website to this day, It is a bullshit claim as c-99 is not true breeding as he claims, you can see how the lines segregate in all the work done with c99 in the many years since it came out. It may be true breeding for some traits but over back crossing causes segregation of traits and you will not have true breeding replicas of the original unless the p-1 were very homozygous to begin with.

Great info in this thread.
 
#100
c-99 is all over the map..and thatsok
not that i want stabilty..i just want gems..
attaining stabilty imho
gets in the way..becareful what ye wish for..unless its "just stabilty"
 
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