CANNABIS BREEDING

SEX

In the cell core of a marijuana plant are 10 couples of chromosomes present. One of these couples will determine if the plant will be a male or a female. When the plant has two X-chromosomes it will be a female and if it has an X and Y-chromosome then it will be a male. The sex of the plant will be determined at the moment of fertilization. On this moment the female chromosomes will link with the chromosomes of the male. If the male chromosome that determines the sex of the plant is an X-chromosome then the plant will be a female and otherwise it will be a male. But the development of the plant is not completely determined by the presence of X and Y chromosomes. Also outsides circumstances can have an influence on this and because of these external circumstances a female plant can bloom like a male and visa versa. 

PROPERTIES

At the moment of fertilization the chromosomes of the female will connect with the chromosomes of the male. In this way 10 couples of chromosomes are created. On everyone of these chromosomes a number of genes a situated. The two chromosomes that make a couple have genes on the same places (loci). Such a gene on a locus consists of a property (allele). These properties (alleles) determine how the plant will look, grow, smell, bloom, and so on. If now on both chromosomes of a couple, the same property (allele) will be at the same place (locus), then the plant will show this property. In this case is said that the plant homozygous is for this property. If we have to do with different alleles then the dominant allele will determine the property while the property of the recessive allele will remain hidden. The plant is then heterozygous for this property. 

TRUE BREEDING 

If you buy a package of seeds and let nature do its way, then of course you will have offspring. And if you let these children have children, and so on........ In most cases the plants will start to look differently. Brothers and sisters will not look alike anymore. But in the event that the children continue to look like their parents we speak about a "true breeding strain". True breeding arises if the plant is homozygous on the important properties. This can happen by natural selection or by selective breeding. In both cases plants are taken away that do not meet the requirements. If the work has been done by natural selection then we talk about a "pure bred". These kind of plants then grow in a certain region. But normally we have to do with  stabilized hybrids (products of crossbreeding). Known (more or less) true breeding strains that are developed by selective cultivation are: Skunk # 1, Haze and Shit. 

INBREEDING 

If you want to preserve the properties of a certain plant, very often this is done by inbreeding. By just backcrossing the children with the mother and later grandmother, these children will more and more look like the mother. After 6 times of backcrossing the plant will look very much like the (grand, grand.....) grandmother, whereas after 20 time of backcrossing the new plant will be genetically almost identical to the (grand, grand.....) grandmother. A much-made error is that growers think that in this way they will create a plant that will be on all important points homozygous and therefore true breeders. This is not the case! The plant that is created will genetically be like the (grand, grand.....) grandmother. And if this grandmother was no true breeder her offspring will also not be like this. If you want to create a stable line you need to use selective breeding for a number of generations. 

HYBRID 

By crossing two not related plants you will create a hybrid. These newly created plants are called F1. If the F1 plants are backcrossed to the mother then their offspring often will be called F2. Also F1 crossings between brothers and sisters are called F2 and sometimes even crossings between F1 plants of different lines are called F2. I presume however that, in most cases when breeders are talking about a F6, they mean by this that the plant was backcrossed for 6 generations, this to reinforce the properties of the mother. But be aware, this plant will probably not be stable. Even not if it is a F20. What you best can do is to select the plants that you like the most and use their clones for growing and blooming.  

THE STRENGTH OF THE HYBRID (HYBRID VIGOR) 

With "HYBRID VIGOR" is meant something like the strength of the hybrid. This is however only the case with a crossing of two stable plant lines (the plant is then on important properties homozygous and therefore true breeding). The F1 plants that you produce in this way will be all identical and very strong. Because of this, an enormous improvement on certain characteristics can arise. So it can be for example that these F1 plants grow much more rapidly or produce bigger buds then their parents. Another advantage of this F1 is that all plants will be identical. Selection of the best plants is of course not needed anymore. The strength of the hybrid will however decrease if you go on with breeding. A F2 is therefore qualitatively lesser then the F1. This because of the recessive alleles that nicely hided in the F1 and can come forward in the F2. Furthermore the offspring of F1 plants will no longer be identical. 

FERTILIZING 

Fertilizing the females is best done when the buds are entirely formed (but the "hairs" should still be white). In this way you get the biggest amount of seeds. When the right moment is there, it is sufficient to place one blooming male plant in the room. In the case that you only want a limited number of seeds then you can also fertilize for example one single branch. You have to gather the pollen of the male plant and put them in a paper sack. After this, you put the paper sack over a branch of a female plant and close it completely, so no pollen can escape. Shake the branch with the sack now considerable. After this you have to wait approximately for two hours before shaking the sack again. A couple hours later you can remove the sack and within two weeks you will see that the development of the seeds has started. In about three to six weeks the seeds will be ripe. A in this way fertilized branch can contain hundreds of seeds.