Back-crossing and cubing 

The act of taking a chosen sibling from for example the F2 generation and crossing it back to the P1 parent to enforce its parents genes.
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- which 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 to 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 means the boy being used 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 - all 100% show the desired phenotype, but only 50% will breed true for it.

If the phenotype is controlled by a recessive condition -  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, - 25% AA, 50% Aa and 25% aa
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 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.

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

Feminizing and Reversing cannabis strains
Feminizing cannabis strains has become extremely popular in recent years and has opened up the door for many other breeding techniques which are proving to be quite popular for the preservation of unique clones and lines that growers would not have access to.
Hobby and commercial growers alike love the idea they can purchase 200 seeds and not have to worry about males, producing a uniform crop.
Feminizing a cultivar is not too difficult to achieve. How ever when it comes to doing it well, there is some tips you should know. 

• Creating a feminized line that is 100% female seeds starts with a good selection of mother plant. Truebred/stabilised varieties that do not have any hermaphrodites in their genetics are best. These mothers need to be able to withstand some stress, but still remain female... if they herm with a light leak, or change in temperature or time... they are not a strain worth persuing to feminize - seeds from strain that hermaphrodites on its own will appear in its off spring seed lines rendering them more of a pain in the arse than usefull.

• Seeds created by feminizing do not make good mother plants for cloning - they will work for the first few months, but quickly they will degenerate the more you hack clones from them.

• Plants that are grown by a feminized seed are not good to feminize a second time - they will be spindly plants that do not grow well.

How to feminize​

1. Select a stable truebred female cannabis plant, stress tested to make certain she is ONLY a fem and doesn't hermaphrodite.

2. Select one healthy branch and tie a ribbon to the base of it. So there is no confusion - spray the same branch every day.

3. 2 weeks before flowering start to spray the top 3 to 4 nodes at the base of their stem every day (during lights off) with a colloidal silver solution  [ RO water and colloidal silver 30ppm+ preferrably 40ppm. ] [ Solutions can be purchased such as "Tiresias Mist"  from ebay, colloidal silver is easily made at home - search google. Silver thiosulfate also works well ]

4. Spray the same nodes on the same branch every day  (at least once or twice a day) when lights are off. for the next 2 to 4 weeks

5. Watch for pollen sacks to form

6. Stop spraying when sacks are formed

7. Pollen may be collected  and frozen when sacks begin opening. Or room may be left full of the same and different females to be immediately pollinated creating feminized seeds.
    

Using your female pollen to then pollinate a clone of the same variety is called "selfing" (S1)  this is a classic version of a feminized seed. Many breeders choose to use that same female pollen to then pollinate different female strains - this creates a "reversed" fem commonly now termed as "R1" - The host plant takes the female  pollen and creates a line that is 95% similar to is parent host. This is a quick way for a breeder to release many different lines at once - some breeders are even doing reverse back crosses (female pollen from original P1 mother plant used to feminize) and are having great results. 
For breeders selfing or reversing gives the breeders access to a line in seed form that is not otherwise available (it may be clone only). 
commercial and hobby growers that in their own rights are restricted by space like to purchase feminized lines so their valuable space and electricity is not consumed nurturing a big male plant to health that to them is useless.

​

Breeding Autoflowering varieties

What is Autoflowering?
                              - Commonly referred to as "ruderalis" auto flowering varieties will flower automatically without requiring a dark period (photoperiod). They are the choice of many growers for their ease of growing - no worries about light leaks or timing, and they provide a nice yield in 90 days from seed pop allowing committed growers to achieve 4 harvests per year.
Autoflowering seeds are available from many seed retailers around the world.
Although some traits are complicated and require more than one gene to express, autoflowering is one of the most basic types of genetic traits and follows the laws of simple recessiveness and dominance. Specifically, it is a recessive trait. 

For breeders, both experienced and aspiring, autoflowering is an easy trait to spot. It is easy to determine if a given  plant is autoflowering or standard just by keeping it in short (or non-existent) dark periods for a few weeks. If the plant stays in vegetive growth, it is standard. If it flowers it is autoflowering.
 

Chromosomes From the Male Plant
Cannabis is a diploid, in other words, it gets one chromosome from the pollen of the father, and one from the ovum of the mother. This means it will have two genes (one from each chromosome strand), each of which can be one of two alleles, either autoflowering or not.
If we refer to the photoperiod (standard) allele as P (uppercase) , and the non-photoperiod (a allele as p (lower case), then the child plant will receive two—one from each parent. If the father is true breeding (homozygous) for photoperiod, it will have the allele P on both genes—the same is true for the mother.

Seeds made from such pairings will result in offspring that is also true breeding for photoperiod. The father will contribute either a P or a P (because he has two big Ps, and will pass on one or the other). The mother will contribute either a P or a P (because she has two, and will pass on one or the other).

While technically there are four combinations possible, effectively it doesn’t make much difference because all of the combinations result in PP (true breeding for photodependancy). This is why breeding a standard cannabis plant with another standard cannabis plant will result in standard cannabis offspring. The same is true of autoflowering.

True breeding an Auto-flowering hybrid strain.
If both parents are true breeding for autoflowering, they will each have pp, and their offspring will autoflower (since they will receive a p from each parent). However, if one parent is PP (standard) and the other is autoflowering (pp), then all of the seeds will be Pp, since they will get one of the two P from the first parent, and one of the two p from the second parent. Having both the allele P and the allele p (heterogeneous for autoflowering) makes them a hybrid.

Since they have the alleles for both photodependancy and autoflowering, their phenotype  will depend on dominance. Dominance determines which one breaks the ties in these instances.

In this case, photoperiod is dominant, so the resulting Pp seeds will all be photodependant. This is why the first generation after crossing a true breeding standard plant with a autoflowering plant will create seeds that are photodependant and will not autoflower.
 

However, the hybrid seeds aren’t useless. If the heterogeneous seeds from the above are crossed together, then the autoflowering trait will reappear:

• The hybrid father will contribute either his P or p.

• The hybrid mother will contribute either her P or p.

• The resulting combinations are either PP, Pp, pP or pp.

• The PP will be true breeding for photodependancy, and will show photodependancy.

• The Pp and pP will be heterogeneous for photodependancy but will still show photodependancy because of dominance.

• The pp will be true breeding for autoflowering, and will show autoflowering.

It is important to note that because of dominance there is no way to visually tell the difference between PP, pP and Pp. They will all be photodependant—only the recessive pp from this generation can be easily identified as true breeding.

A practical experiment can illustrate the above:

Step 1: Take a standard cannabis plant and cross it with an autoflowering variety. It doesn’t matter which supplies the pollen as long as one is male and the other female.

Step 2: Grow out the resulting seeds. They should act as if they were standard seeds. Select the best male and at least one female and cross them together.

Step 3: Grow out those seeds under growth (no long dark period) lighting. Due to the reasons explained above, there should be about 75% that don’t autoflower and 25% that do. The more seeds planted, the closer the results should be to the 75%-25% ratio.

One benefit to breeding for a recessive trait is that all of those that autoflower would have been true bred for autoflowering and can be bred together to make more autoflowering seeds. 

Even if a breeder isn’t fond of autoflowering varieties, the process and learning experience of working with them can help expand their understanding of how genetic traits work in a way that is easy to see and will give tangible results and feedback.

Applying Mendelian genetics to simple traits in the real world can not only help cement an understanding of the basic principles of genetics, but can impress onlookers when predictions are proven accurate, or at least reasonably close.