From Robert Connel Clarke’s book
"Marijuana Botany
An Advanced Study: The Propagation and
Breeding of Distinctive Cannabis "
Parental plants are selected which most nearly approach the ideal. If a desirable
trait is not expressed by the parent, it is much less likely to appear in the
offspring. It is imperative that desirable characteristics be hereditary and not
primarily the result of environment and cultivation. Acquired traits are not
hereditary and cannot be made hereditary. Breeding for as few traits as possible
at one time greatly increases the chance of success. In addition to the specific
traits chosen as the aims of breeding, parents are selected which possess other
generally desirable traits such as vigor and size. Determinations of dominance
and recessiveness can only be made by observing the outcome of many
crosses, although wild traits often tend to be dominant. This is one of the keys to
adaptive survival. However, all the possible combinations will appear in the F2
generation if it is large enough, regardless of dominance.
Now, after further simplifying this wonderful system of inheritance, there are
additional exceptions to the rules which must be explored. In some cases, a pair
of genes may control a trait but a second or third pair of genes is needed to
express this trait. This is known as gene inter action. No particular genetic
attribute in which we may be interested is totally isolated from other genes and
the effects of environment. Genes are occasionally transferred in groups instead
of assorting independently. This is known as gene linkage, These genes are
spaced along the same chromosome and may or may not control the same trait.
The result of linkage might be that one trait cannot be inherited without another.
At times, traits are associated with the X and Y sex chromosomes and they may
be limited to expression in only one sex (sex linkage). Crossing over also
interferes with the analysis of crosses. Crossing over is the exchanging of entire
pieces of genetic material between two chromosomes. This can result in two
genes that are normally linked appearing on separate chromosomes where they
will be independently inherited. All of these processes can cause crosses to
deviate from the expected Mendelian outcome. Chance is a major factor in
breeding Cannabis, or any introduced plant, and the more crosses a breeder
attempts the higher are the chances of success.
Variate, isolate, intermate, evaluate, multiplicate, and disseminate are the key
words in plant improvement. A plant breeder begins by producing or collecting
various prospective parents from which the most desirable ones are selected and
isolated. Intermating of the select parents results in offspring which must be
evaluated for favorable characteristics. If evaluation indicates that the offspring
are not improved, then the process is repeated. Improved off spring are
multiplied and disseminated for commercial use. Further evaluation in the field is
necessary to check for uniformity and to choose parents for further intermating.
This cyclic approach provides a balanced system of plant improvement.
Please note the section where F2 crosses are mentioned and the linking of gene expression to sex chromosomes.
The last paragraph is where the benefit of seeds like this will become apparent, if you want to make your own stable line, to make your own F1 cross then these seeds are already at F2 stage and would save you a generation.
But if you want to make your own stable line, to make your own F1 cross then you would be better off starting with two already stable lines of known qualities from which to make your F1, then F2 crosses…
As such, to my mind, even for their stated purpose these seeds are essentially worthless.