Cubing - A myth by Chimera

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trinityalps

trinityalps

61
8
Interesting read Chimera.
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.

Adding my 2 cents. Me too. C99 was a flighty 2 hour, heart racing buzz. The Apollos I've had the pleasure working with have a superior buzz for me, yield, and scent. Plays well with others in crosses too, though so does Cindy.
 
Krypto

Krypto

1,162
263
I've been going around and around for about a year trying to decide on two or three sativas that I want to get. In the meantime I've been able to get green crack, sour chiesel at cetera from my partner at Harborside.
And I would probably go with the Apollo 13 before the Cindy simply because from what I've read the effect is a little mellower with the Apollo. I honestly haven't had a straight Cindy or or a straight Apollo 13 so I can't tell from experience. Which brings me to my point a buddy on the farm told me that Chineras would be a good starting point for my search for one of the other sativas I've been wanting to try the xj13 comma from every description that I've read and testimonials I've read I believe that this is probably more of what I'm looking for. Does anyone have any xj13 seeds? Or a referral to a Seedbank that I can order them?
 
H

Heavenlygoo

7
3
Hey everybody,

I know this thread is actually talking about how bxing and cubing is a myth but i just wanted to know if any of you guys and gals have grown out Gooeybreeders 106% pure gooey from 09?

If you have, have you noticed any distinctions between that one and versions of it less cubed?

Also from a beginners point of view is there any reason to take a cubed line that far, or your just at that point trying to grow out plants that are 100 percent like the mom gooey with only a 6% variance from the skunk1 used to cube the line.

Thanks and sorry if thats a dumb question

HG
 
HeidisGrace

HeidisGrace

22
13
Wow that is painful for me to read.... I must have been pretty stoned when I wrote that, now years ago. I'm glad at least that it's info that has spread a little knowledge and perspective into the community over the years.. I do however need to re-write it...

Here's a snipet on backcrossing from the breeding chapter I wrote for Jorge's most recent version of the bible.

Backcross Breeding –
A type of breeding that involves repeated crossing of progeny with one of the original parental genotypes; cannabis breeders most often cross progeny to the mother plant. This parent is known as the recurrent parent. The non-recurrent parent is called the donor parent. More widely, any time a generation is crossed to a previous generation, it is a form of backcross breeding. Backcross breeding has become one of the staple methods clandestine cannabis breeders use, mainly because it is a simple, rapid method when using greenhouses or grow
rooms, and requires only small populations. The principle goal of backcross breeding is to create a population of individuals derived mainly from the genetics of one single parent (the recurrent parent).

The donor parent is chosen based on a trait of interest that the recurrent parent lacks; the idea is to introgress this trait into the backcross population, such that the new population is comprised mainly of genetics from the recurrent parent, but also contains the genes responsible for the trait of interest from the donor parent.

The backcross method is a suitable scheme for adding new desirable traits to a mostly ideal, relatively true-breeding genotype. When embarking on a backcross breeding plan, the recurrent parent should be a highly acceptable or nearly ideal genotype (for example, an existing commercial cultivar or inbred line). The ideal traits considered for introgression into the new seed line should be simply inherited and easily scored for phenotype. The best donor parent must possess the desired trait, but should not be seriously deficient in other traits. Backcross line production is repeatable, if the same parents are used.

Backcross breeding is best used when adding simply inherited dominant traits that can easily be identified in the progeny of each generation (example 1). Recessive traits are more difficult to select for in backcross breeding, since their expression is masked by dominance in each backcross to the recurrent parent. An additional round of open pollination or sib-mating is needed after each backcross generation, to expose homozygous-recessive plants. Individuals showing the recessive condition are selected from F2 segregating generations and backcrossed to the recurrent parent (see example 2).

Example 1– Backcrossing: Incorporating a dominant trait

Step1– Recurrent Parent × Donor Parent
|
V
F1 Hybrid generation

Step 2 – Select desirable plants showing dominant trait, and hybridize selected plants to recurrent parent. The generation produced is denoted BC1 (some cannabis breeders break from botanical convention and denote this generation Bx1. BC1= Bx1).

Step 3 – Select plants from BC1 and hybridize with the recurrent parent; the resulting generation is denoted BC2.

Step 4 – Select plants from BC2 and hybridize with the recurrent parent; the resulting generation is denoted BC3.
.

Example 2 Backcrossing: Incorporating a recessive trait

Step1– Recurrent Parent × Donor Parent
|
V
F1 Hybrid generation

Step 2 – Select desirable plants, and create an F2 population via full sib-mating.

Step 3 – Select plants showing the desired recessive trait in the F2 generation, then hybridize selected F2-recessive plants to the recurrent parent. The generation produced is denoted BC1.

Step 3 – Select plants from BC1, and create a generation of F2 plants via sib-mating; the resulting generation can be denoted BC1F2

Step 4 – Select desirable BC1F2 plants showing the recessive condition, and hybridize with the recurrent parent; the resulting generation is denoted BC2.

Step 5 – Select plants from BC2, and create an F2 population via sib-mating; denote the resulting generation BC2F2.

Step 6 – Select plants showing the recessive condition from the BC2F2 generation, and hybridize to the recurrent parent; the resulting generation is denoted BC3.

Step 7 – Grow out BC3, select and sib-mate the most ideal candidates to create an F2 population, where plants showing the recessive condition are then selected and used as a basis for a new inbred, or open-pollinated seed line.

This new generation created from the F2 is a population that consists of, on average, ~93.7% of genes from the recurrent parent, and only ~6.3% of genes leftover from the donor parent. Most importantly, one should note that since only homozygous-recessives were chosen for mating in the BC3F2 generation, the entire resulting BC3F3 generation is homozygous for the recessive trait, and breeds true for this recessive trait. Our new population meets our breeding objective. It is a population derived mainly from the genetics of the recurrent parent, yet breeds true for our introgressed recessive trait.


Backcross derived lines are expected to be well-adapted to the environment in which they will be grown, which is another reason backcrossing is often used by cannabis breeders who operate indoors. Indoor grow rooms are easily replicated all over the world, so the grower is able to grow the plants in a similar environment in which they were bred. Progeny therefore need less extensive field-testing by the breeder across a wide range of environments.

If two or more characters are to be introgressed into a new seed line, these would usually be tracked in separate backcross programs, and the individual products would be combined in a final set of crosses after the new populations have been created by backcrossing.

The backcross scheme has specific drawbacks, however. When the recurrent parent is not very true-breeding, the resulting backcross generations segregate, and many of the traits deemed desirable to the line fail to be reproduced reliably. Another limitation of the backcross is that the “improved” variety differs only slightly from the recurrent parent (e.g., one trait). If multiple traits are to be introgressed into the new population, other techniques such as inbreeding or recurrent selection may be more rewarding.

Hope that's a little more clear......
Respectfully,
-Chimera
Hi. Thank you for this information. It is going to take me a while to get used to the logic. I wonder if I could ask your advice please. I have some Transkei origin seeds and some F1s from a cross with a Transkei heirloom male. I have it on good authority that my origin seeds are true Transkei Sativa but who knows, with Skunk and others finding their way into our plantations, it could potentially be tainted. I want to grow the best Transkei Sativa I can and breed true. What would you advise as the breeding protocol for my micro-grow? We are about to start outdoor breeding in the next month here in South Africa.
 
Palindrome

Palindrome

26
3
Cubing.......a myth.

Here's breeder chimera's take on the subject:

"you’ve just discovered the biggest myth (IMNSHO) of marijuana breeding- it is a mistake that almost EVERYONE makes (including many of the most respected breeders!).

Backcrossing will not stabilize a strain at all- it is a technique that SHOULD be used to reinforce or stabilize a particular trait, but not all of them.

For e.g.- G13 is a clone, which I would bet my life on is not true breeding for every, or even most traits- this means that it is heterozygous for these traits- it has two alleles (different versions of a gene). No matter how many times you backcross to it, it will always donate either of the two alleles to the offspring. This problem can be compounded by the fact that the original male used in the cross (in this case hashplant) may have donated a third allele to the pool- kinda makes things even more difficult!

So what does backcrossing do?
It creates a population that has a great deal of the same genes as the mother clone. From this population, if enough plants are grown, individuals can be chosen that have all the same traits as the mother, for use in creating offspring that are similar (the same maybe) as the original clone.
Another problem that can arise is this- there are three possibilities for the expression of a monogenic (controlled by one gene pair) trait.

We have dominant, recessive, and co-dominant conditions.

In the dominant condition, genotypically AA or Aa, the plants of these genotypes will look the same (will have the same phenotype, for that trait).

Recessive- aa will have a phenotype

Co-dominant- Aa- these plants will look different from the AA and the aa.

A perfect example of this is the AB blood types in humans:

Type A blood is either AA or AO
Type B blood is either BB or BO
Type AB blood is ONLY AB
Type O blood is OO.

In this case there are three alleles (notated A, B, and O respectively).

If the clone has a trait controlled by a co-dominant relationship- i.e. the clone is Aa (AB in the blood example) we will never have ALL plants showing the trait- here is why:

Suppose the clone mother is Aa- the simplest possibility is that the dad used contributes one of his alleles,
let us say A. That mean the boy being use for the first backcross is either AA or Aa. We therefore have two possibilities:

1) If he is AA- we have AA X Aa- 50% of the offspring are AA, 50% are Aa. (you can do the punnett square to prove this to yourself).

In this case only 50% of the offspring show the desired phenotype (Aa genotype)!

2) If the boy being used is Aa- we have Aa X Aa (again do the punnett square) this gives a typical F2 type segregation- 25% AA, 50% Aa, and 25% aa.
This shows that a co-dominant trait can ONLY have 50% of the offspring showing the desired trait (Aa genotype) in a backcross.

If the phenotype is controlled by a dominant condition- see example #1- all 100% show the desired phenotype, but only 50% will breed true for it.

If the phenotype is controlled by a recessive condition- see example #2- only 25% will show the desired phenotype, however if used for breeding these will all breed true if mated to another aa individual.

Now- if the original dad (hashplant) donates an 'a' allele, we only have the possibilities that the offspring, from which the backcross boy will be chosen, will be either Aa or aa.
For the Aa boy, see #2.
For the aa boy (an example of a test cross, aa X Aa) we will have:
50% aa offspring (desired phenotype), and 50% Aa offspring.

Do you see what is happening here? Using this method of crossing to an Aa clone mother, we can NEVER have ALL the offspring showing the desired phenotype! Never! Never ever ever! Never!! LOL

The ONLY WAY to have all the offspring show a Aa phenotype is to cross an AA individual with an aa individual- all of the offspring from this union will be the desired phenotype, with an Aa genotype.

Now, all of that was for a Aa genotype for the desired phenotype. It isn't this complicated if the trait is AA or aa. I hope this causes every one to re-evaluate the importance of multiple backcrosses- it just doesn't work to stabilize the trait!

Also- that was all for a monogenic trait! What if the trait is controlled by a polygenic interaction or an epistatic interaction- it gets EVEN MORE complicated? AARRGH!!!!

Really, there is no need to do more than 1 backcross. From this one single backcross, as long as we know what we are doing, and grow out enough plants to find the right genotypes, we can succeed at the goal of eventually stabilizing most, if not all of the desired traits.

The confusion arises because we don't think about the underlying biological causes of these situations- to really understand this; we all need to understand meiosis.

We think of math-e.g. 50% G13, 50% hashplant

Next generation 50% G13 x 50% g13hp or (25% G13, 25%HP)

We interpret this as an additive property:
50% G13 + 25% G13 +25% HP = 75% G13 and 25% hashplant

This is unfortunately completely false- the same theory will apply for the so called 87.%% G13 12.5% HP next generation, and the following 93.25% G13, 6.25% HP generation; we'd like it to be true as it would make stabilizing traits fairly simple, but it JUST DOESN'T work that way. The above is based on a mathematical model, which seems to make sense- but it doesn't- we ignore the biological foundation that is really at play.

I hope this was clear, I know it can get confusing, and I may not have explained it well enough- sorry if that is the case, I'll try to clear up any questions or mistakes I may have made.

Have fun everyone while making your truebreeding varieties, but just remember that cubing (successive backcrosses) is not the way to do it!

-Chimera"
Hello Chimera,
This is a good explanation. I would only add to your comments:
"The above is based on a mathematical model, which seems to make sense but it doesn't - we ignore the biological foundation that is at play" (from you) - In my opinion, no truer words have been spoken! I would like to expand on that a bit for the others:

Cannabis is a predominantly cross-pollinating crop that naturally wants to be dioecious (having male-only and female-only plant types). Yes there are monoecious forms and hermaphrodites, etc. but the species naturally will be a population, not anything even close to a pure breeding line. When you deal with a population-based crop, you need to use population-based plant breeding techniques. Backcrossing is neither a population or pure line only technique - it is neutral. Backcrossing, as explained, can be initially understood using a simple Mendelian (one gene dominant and recessive model like you've explained so well) but it can also be used with populations (the recurrent parent or the line you choose to go back to as a pollinator in your backcrossing program would not be a single plant but a group of plants). My point is that Cannabis is population-based, not pure line, due to its biological nature (an out-crossing population). We need to remember this. The strains that are out there are not cultivars or pure lines in many cases. The best of them will be narrow-based populations (that are unique, uniform, and stable) from doing sib-matings within your newly developed material. I see a few Dutch bred strains that are noted for uniformity (consistent phenos) like White Widow and I would suggest (since I do not know for sure) that these were either selfed then sibbed or straight sib-mated, always with selection, into a narrow genetic-based population. The other aspect I would mention is that the key to most plant breeding strategies is selection. You need to cross, self and sib, to generate genetic diversity in your new material and then - the really important part - plant those lines out and observe them, test them, select only the very best (or maybe none at all - not all projects give you what you are looking for). The serious breeders have a large land base and put thousands of lines out into the field to find the ideal "phenos". These best phenos (the selected ones from the same originating cross) are then re-combined in the end to reconstitute a population. The power of a plant breeding program is directly linked to how many lines you can evaluate in segregating material (all other things being equal). You let that new narrow-based (selected) population inter-mate in a tent and produce the new strain. Your need to recombine the selected lines (all very similar) to make a population - one with males and females (regular). You can always feminize it - that's trivial. This is how I would make a true-breeding cultivar in Cannabis. There is so much more on breeding strategies, techniques - this is the tip of the iceberg. Other population-based crops such as rye and alfalfa typically use a synthetic variety or hybrid variety methods of breeding (and for parts, perhaps backcrossing). These are population-based varieties. I am relatively new to Cannabis and what I've observed so far is that the term "strain" used in the Cannabis world, should not ever be misconstrued as being a true-breeding line; grow enough plants and you'll see (different phenos). Also, when you buy a hybrid - a true hybrid (an F1 in either seed form or plant clone) - know that if that material undergoes natural seed production on its own, it will segregate into an almost infinite collection of genetically different plants (breeders call it the F2 segregating generation). A hybrid is a one-generation phenomenon (other than propagation by cloning).
I'll end with some old plant breeding advice: 1. Really know your parents before making your new crosses; have a clear target, 2. Understand the genetics of the trait in Cannabis before you start (e.g. cannabinoid production (THC etc.) generally behaves in an additive manner as far as I can tell - meaning 25% crossed with 15% gives an average expression in the population that is the mean (20%). but being a population, it can range on either side of the 20%, based on an individual plant basis - this is why selection pressure (screening lots of plants) is key.
Enough for now - hope I'm not boring you.
 
Palindrome

Palindrome

26
3
Wow that is painful for me to read.... I must have been pretty stoned when I wrote that, now years ago. I'm glad at least that it's info that has spread a little knowledge and perspective into the community over the years.. I do however need to re-write it...

Here's a snipet on backcrossing from the breeding chapter I wrote for Jorge's most recent version of the bible.

Backcross Breeding –
A type of breeding that involves repeated crossing of progeny with one of the original parental genotypes; cannabis breeders most often cross progeny to the mother plant. This parent is known as the recurrent parent. The non-recurrent parent is called the donor parent. More widely, any time a generation is crossed to a previous generation, it is a form of backcross breeding. Backcross breeding has become one of the staple methods clandestine cannabis breeders use, mainly because it is a simple, rapid method when using greenhouses or grow
rooms, and requires only small populations. The principle goal of backcross breeding is to create a population of individuals derived mainly from the genetics of one single parent (the recurrent parent).

The donor parent is chosen based on a trait of interest that the recurrent parent lacks; the idea is to introgress this trait into the backcross population, such that the new population is comprised mainly of genetics from the recurrent parent, but also contains the genes responsible for the trait of interest from the donor parent.

The backcross method is a suitable scheme for adding new desirable traits to a mostly ideal, relatively true-breeding genotype. When embarking on a backcross breeding plan, the recurrent parent should be a highly acceptable or nearly ideal genotype (for example, an existing commercial cultivar or inbred line). The ideal traits considered for introgression into the new seed line should be simply inherited and easily scored for phenotype. The best donor parent must possess the desired trait, but should not be seriously deficient in other traits. Backcross line production is repeatable, if the same parents are used.

Backcross breeding is best used when adding simply inherited dominant traits that can easily be identified in the progeny of each generation (example 1). Recessive traits are more difficult to select for in backcross breeding, since their expression is masked by dominance in each backcross to the recurrent parent. An additional round of open pollination or sib-mating is needed after each backcross generation, to expose homozygous-recessive plants. Individuals showing the recessive condition are selected from F2 segregating generations and backcrossed to the recurrent parent (see example 2).

Example 1– Backcrossing: Incorporating a dominant trait

Step1– Recurrent Parent × Donor Parent
|
V
F1 Hybrid generation

Step 2 – Select desirable plants showing dominant trait, and hybridize selected plants to recurrent parent. The generation produced is denoted BC1 (some cannabis breeders break from botanical convention and denote this generation Bx1. BC1= Bx1).

Step 3 – Select plants from BC1 and hybridize with the recurrent parent; the resulting generation is denoted BC2.

Step 4 – Select plants from BC2 and hybridize with the recurrent parent; the resulting generation is denoted BC3.
.

Example 2 Backcrossing: Incorporating a recessive trait

Step1– Recurrent Parent × Donor Parent
|
V
F1 Hybrid generation

Step 2 – Select desirable plants, and create an F2 population via full sib-mating.

Step 3 – Select plants showing the desired recessive trait in the F2 generation, then hybridize selected F2-recessive plants to the recurrent parent. The generation produced is denoted BC1.

Step 3 – Select plants from BC1, and create a generation of F2 plants via sib-mating; the resulting generation can be denoted BC1F2

Step 4 – Select desirable BC1F2 plants showing the recessive condition, and hybridize with the recurrent parent; the resulting generation is denoted BC2.

Step 5 – Select plants from BC2, and create an F2 population via sib-mating; denote the resulting generation BC2F2.

Step 6 – Select plants showing the recessive condition from the BC2F2 generation, and hybridize to the recurrent parent; the resulting generation is denoted BC3.

Step 7 – Grow out BC3, select and sib-mate the most ideal candidates to create an F2 population, where plants showing the recessive condition are then selected and used as a basis for a new inbred, or open-pollinated seed line.

This new generation created from the F2 is a population that consists of, on average, ~93.7% of genes from the recurrent parent, and only ~6.3% of genes leftover from the donor parent. Most importantly, one should note that since only homozygous-recessives were chosen for mating in the BC3F2 generation, the entire resulting BC3F3 generation is homozygous for the recessive trait, and breeds true for this recessive trait. Our new population meets our breeding objective. It is a population derived mainly from the genetics of the recurrent parent, yet breeds true for our introgressed recessive trait.


Backcross derived lines are expected to be well-adapted to the environment in which they will be grown, which is another reason backcrossing is often used by cannabis breeders who operate indoors. Indoor grow rooms are easily replicated all over the world, so the grower is able to grow the plants in a similar environment in which they were bred. Progeny therefore need less extensive field-testing by the breeder across a wide range of environments.

If two or more characters are to be introgressed into a new seed line, these would usually be tracked in separate backcross programs, and the individual products would be combined in a final set of crosses after the new populations have been created by backcrossing.

The backcross scheme has specific drawbacks, however. When the recurrent parent is not very true-breeding, the resulting backcross generations segregate, and many of the traits deemed desirable to the line fail to be reproduced reliably. Another limitation of the backcross is that the “improved” variety differs only slightly from the recurrent parent (e.g., one trait). If multiple traits are to be introgressed into the new population, other techniques such as inbreeding or recurrent selection may be more rewarding.

Hope that's a little more clear......
Respectfully,
-Chimera
Dead on. Classic textbook explanation. You are obviously a well educated Plant Breeder (classicly trained). Nice to meet a fellow breeder. I wish I had the land base to conduct a proper recurrent selection program (like the commercial hemp programs) but I do not. All I do these days is make F1 crosses and add to my germplasm collection until the day I can line out in a field somewhere (in the near future). All programs end up being designed around the resources you have available. For me, this is a hobby - and a fun one!
 
Palindrome

Palindrome

26
3
Greetings Tobor

My intent is most certainly not to speak for Chimera, but I am applying my answer to the one of your questions that I can reasonably respond to. In terms of breeding techniques: the conclusion of 'good' or 'bad' is verifiably dependant on application and intent.

All that should be inferred is: Backcrossing is not the most reliable method of stabilizing traits that are expressed co-dominantly or ones which are polygenic.

Co-dominance relates to two alleles of a gene pair in a heterozygote that are both fully expressed. Simplistically, both the dominant and the recessive forms of a trait are expressed in what could be termed a 'mixed phenotype'.

Going back to Mendel: If dominant is red, and recessive is white, then co-dominant would be pink.

Polygenic refers to the combined action and expressed interaction of alleles of more than one gene resulting in a single trait.

This response is an analogy to the process of backcrossing: It throughly answered only one of your questions.

Sincerely,
Charles.
Greetings grapepunched

...if I cross an F1 to an F2, what is that considered?....grapepunched

It is considered a Backcross.
Commonly notated: BX
Conventionally notated: BC

The exact notation is example specific with the assumption that the same genetic line is being referenced.

Sincerely,
Charles.
correct (technically) but you should be aware that your new F1 (F1 crossed with a single F2 from the same F1 cross) is now on average theoretically containing 50% of that F2 plant's nuclear genetics and 50% of the original hybrid F1 cross. This kind of crossing would only ever make sense if you were ONLY starting a backcross program (meaning your next move is to cross again onto that F2 selection (which you keep growing in vedge or collect and store pollen for future crossing because that F2 only exists that one generation - you have no way of propagating it to use as a recurrent parent in future backcrosses. You could probably pull this off once or twice at most, I'm guessing due to practical aspects. Fyi - you can collect and store pollen (months, years with right technique) with Cannabis - more on that later...
 

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