The Cannabis Breeder's Bible (15 page)

Biogenetics also shows that acquired characteristics cannot be inherited. For example, an athlete does not pass on his marvelous long jumping skills to his or her child through inheritance. Darwin believed that this was possible and he has since been proven wrong.

Plants and animals can produce offspring that have traits for defense against certain environmental conditions. The traits are not new genetic traits (unless they are mutated genes which bring about the trait), but may be dormant genetic material that is suddenly turned on. This means that plant genetic material already contains traits that are needed to combat problems found in nature. It does not mean that the environment causes these new genes to be created.

Mendel discovered that genes are shuffled in the genetic combination of an individual, and if parents breed then new genetic recombination comes about, but these have laws attached to them and we have talked about these in chapter 2 (Hardy-Weinberg). This tells us that natural selection DOES NOT PRODUCE NEW GENES, but only selects genes for phenotype expression that are already present in a population.

This leaves us with the final conclusion that mutations are the only way an organism can generate NEW genetic material. However it appears that nearly all types of mutations are not controllable, but random.

If there was a nuclear fallout near a large plantation of various populations of cannabis plants, and the radiation caused mutations, the types of mutations would probably end up killing every single plant in those populations. The chances that a new gene would be hatched by a plant to defend itself against the very thing that caused the mutation in the first place is extremely unlikely.

What is more likely is that a plant might have awakened a pre-existing gene to combat the problem, but this gene would have been around before any mutation was induced by the radiation. The current scientific model for adaptability in evolution suggests that environmental factors may affect some of the plant’s genes to make it resistant to the negative aspects of the growing environment (unproven and only a hypothesis). Essentially the plants that cannot survive the disadvantageous environment simply don’t make it and thus do not contribute any of their genes to next gene pool. The ones that survive either already have the gene they need to survive or may have mutated, there and then, to adapt to that disadvantageous environment—however mutations are not controllable nor do they respond by actually setting out to create a gene that defeats the negative environmental influences. It must appear by accident—a ‘one-off’—in order to fit the current scientific model of evolution.

There is no evidence in science that suggests that mutations can produce an organism that is more viable than its parents in the same environment. But we are also faced with the fact that plants have evolved to some degree through mutation.

So this method of evolution by mutation does happen, but it does not mean that the organism will:

1. Survive the mutation.

2. Be better than its parents.

In most cases mutations result in:

1. Nonviable organisms that produce nonviable offspring.

2. A serious disruption of genetic material that can cause death.

3. A new gene that is not viable or has no purpose.

However a mutation may:

1. Bring about new genetic material that is viable and was not present before.

2. Improve a feature of an organism.

Mutation control is a rapidly developing new technology and there are different costly procedures in place which can manipulate DNA, but for the purpose of the average cannabis breeder this is not accessible nor is it considered appropriate because of concerns over genetically modified (GM) crops.

A living cell is a very complex organ. A cell may have evolved through mutation to be what it is today, but the chances of that happening are very slim. One can imagine the analogy of a monkey hitting keys on a typewriter at random. It is possible that the monkey may spell a small three-letter word or may eventually type a six-letter word with enough time and random work. The monkey may even type a sentence if the duration of the experiment is long enough. This is what mathematicians call “probability”. With an infinite amount of time and work the monkey can theoretically type a book or even type a book that has already been written, but the chances of this happening are extremely slim.

The point is that a living muscle or organ like the brain is not impossible to create via mutations of living cells, but we are reminded that the chances of this happening are nonexistent in our lifetime, or even in the same time as it took the Earth to form and get to where it is today. Scientists understand that there are many questions that need to be asked behind the actual foundation of mutation theory.

Neurophysicians understand that various organs in the human body are so complex that it would be hard to imagine mutations being responsible for their development. Also, we appear to have organs that are fully developed, not partially developed. Some may claim that the brain uses 1/16 of its capacity but it is more than likely that we do not yet understand what the other 15/16s does. We have made mistakes like this in the past, for instance saying that the human appendix has no function but maybe when we were apes we used them for some purpose. Now it is clear to scientists that the appendix helps develop antibodies for the intestines and protects part of the intestine from developing harmful growths such as cancer.

All of these questions must be looked at before we accept that evolution through mutation is the key to all the variations that we see in life today. More than likely it is not the only key.

MUTATIONS

In cannabis cells DNA undergoes chemical changes all the time, especially during mitosis. These changes are very quickly repaired, bringing the DNA back to its original format. There are circumstances where the chemical change will not undergo DNA repair because of a problem.This results in a mutation of the DNA.

In some cases there is a basic substitution of DNA during mutation.This is called “point mutation” or “transition” or “transversion,” depending on the type of point mutation that takes place. Another type of mutation is the “mussense missense” mutation. This involves a new nucleotide altering the codon which in turn alters amino acids in the protein content of the DNA. The codon is a group of three consecutive nucleotides that together form a unit of the genetic code and determine which amino acid is added at a particular point in protein synthesis.

“Silent mutations” are another type of mutation, but they do not appear to change DNA and can only be seen in gene sequencing.

“Splice site mutations” occur when a mutation effects a nucleotide signal. If the signal is altered and translated wrongly then protein mutation will occur, which effects the DNA.

“Insertion mutations” and “deletion mutations” occur at the base protein level when a violent mutation causes a new gene to appear or one to be deleted. There can be a total and complete shift in the DNA sequence and this type of mutation can be quite disastrous to the organism if it affects a high number of genes. If it only affects one gene, then the mutation may be beneficial. If it affects more than one gene, then the chances of a beneficial mutation are decreased as the mutation will be 50% good and 50% bad at best. The 50% bad would be enough to cause severe problems with the organism.

“Duplication” is a doubling of part of the genome. A crossover between chromatids that are out of phase with each other can produce one chromatid with a duplicated gene and the other having two with deletions. This causes an imbalance in the gene and the mutant gene becomes dominant. This is also a problem for future offspring.

“Translocations” are another type of mutation, one that causes a gene to break, which simply obliterates it or causes it to become a hybrid gene.

What is even more interesting is that a huge percentage of genes in the cannabis plant do not appear to contribute anything to the phenotype of the plant. So if we think about this coupled with plant diversity and then couple that with mutation theory, it does make us ask a lot of questions about why we have so many different organisms on this planet in such a short space of time.

All of the above mutations result in two broad types of mutations. These are “somatic mutations” and “germline mutations”.

A mutation that occurs in somatic cells can end up killing the cell or seriously damaging it. Germline mutations will be found in all the cells that came from the zygote. Every one of the offspring’s cells will contain this mutation, passing it down from generation to generation where breeding permits it.

Now that you understand what a mutation is, let’s move forward and see some environmental and growing factors that can cause mutations.

WHAT CAUSES A MUTATION

Mutations that are passed through from parent to offspring are called germline mutations. Germline mutations have traits that can be treated much like any other trait. We will find that the genotype of the mutant gene can be dominant homozygous, heterozygous or recessive homozygous.

Since there are many things found in nature that can cause a mutation, some man-made, some not, we would find it hard to list them all here. Here are a couple of factors that are known to breeders at this time and these are the ones that you should know about. There are five main factors as follows:

1. Stress.

2. Genotype.

3. Age.

4. The mutation of cuttings.

5. Transfer techniques.

Let’s go through these one by one.

Stress

In
The Cannabis Grow Bible
we talked about plant stress and how it can effect optimal growth. What we did not mention was that stress factors can affect DNA repair. So anything that stresses a plant has the potential to create a mutation.

What causes stress? Anything that your plant does not like will stress it, such as: overfeeding, overwatering, heat, pest damage, accidents, pH problems, soil problems, root damage…the list can go on and on.

How much stress a plant must endure before it expresses a physical mutation is not clear, nor is this mutation controllable in any way via stress.

Genotype

If a weak plant is developed, with genotypes that are not very protective or don’t help it to grow well then the plant is at risk of mutating under stressful conditions. It is doubtful that a plant would exist like this in nature because it would have died long ago.

However indoor breeding projects may bring such a plant about. Again a weakling plant will have trouble repairing DNA and more than likely over time develop a mutation or a number of mutations.

Age

As the plant gets older it will create new cells to replace older ones. Eventually the plant will die. Before the plant dies there will probably be a problem with chromosome division and this is one way that the plant knows that its work here is coming to an end. When this happens DNA repair may be affected, causing a mutation to occur. Taking a cutting from an old dying mother is never really a good idea because of this so keep cloning new mother plants every few grows.

The Mutation of Cuttings

Breeders have noticed that clones can change in phenotype expression over a long period of time after constant cloning from the same mother plant. This has led many growers and marijuana writers to inaccurately believe that clones lose some form of genetic integrity. Well-maintained clones will not lose any such thing. This mutation of cuttings is troublesome since a clone is supposed to be an exact genetic replication of the parent plant it came from.

It is not understood how many times the same plant must be cloned for this to happen, but the figure looks to be from well into the thousands to maybe tens of thousands, although it is possible that the mutation can occur through less cuttings. In theory and practice a clone should be able to reproduce its exact genetic code indefinitely.

Paradise Seeds generate a new population of clone mothers kept under fluorescent lights on moveable trays.These female clones will be pollinated for seed production.