Nevil Schoenmakers is an iconic figure in the cannabis world, known for his significant contributions to plant genetics. Here’s an illustrative example of how Nevil might have applied the cubing technique to stabilize a particular genetic trait, using a simplified process based on his methods and practices.

Context

Let's assume that Nevil Schoenmakers discovered a particular phenotype with a distinctive trait, such as a unique flavor or color. He wants to stabilize this trait across generations to create a pure variety that consistently expresses this characteristic.

Example: Stabilization of a Unique Flavor Using Cubing

1. Discovery of the Phenotype

2. Initial Crossing

Nevil starts by crossing this special plant with another unrelated but genetically compatible plant. This initial cross (F1) will produce individuals that all carry the trait.f as heterozygotes (Ff), because rare flavor is recessive.

3. First Backcross (Backcross B1)

To increase the gene frequencyf, Nevil makes a first backcross (B1) between the F1 plant (Ff) and the original parental plant (ff).

Crossing:

• Parent 1 (original) :ff (rare flavor)
• Parent 2 (F1) :Ff (rare flavor)

• Ff : 50%
• ff : 50%

In this B1 generation, about 50% of the plants will express the rare flavor.

4. Second Backcross (Squaring B2)

Nevil repeats the process with the B1 generation, crossing the B1 plants that express the rare flavor with the parent plant.ff. This is often called "squaring".

Crossing:

• Parent 1 (B1 with rare flavor) :ff
• Parent 2 (F1) :Ff

• ff : 75%
• Ff : 25%

The frequency of the linef increases in the B2 generation, with about 75% of plants expressing the rare flavor.

5. Third Backcross (Cubing B3)

To further stabilize the trait, Nevil performs a third backcross (cubing), crossing the B2 plants with the parent plantff.

Crossing:

• Parent 1 (B2 with rare flavor) :ff
• Parent 2 (B1) :Ff

• ff : 87.5%
• Ff : 12.5%

The frequency of the linef is now increased to approximately 87.5% in the B3 generation, with a high proportion of plants expressing the rare flavor.

6. Pre Conclusion

After cubing, Nevil managed to stabilize the rare flavor trait, with a high probability of obtaining individuals with the desired flavor. This shows how cubing, by combining successive backcrosses, allows to increase the concentration of the desired trait while reducing the frequency of undesired traits.

Important Notes

• Selection : Nevil would also select the best plants in each generation to ensure that they expressed the desired trait and were genetically the most stable.
• Selective Pressure : Selective pressure and population size are crucial to avoid loss of genetic diversity and maintain trait integrity.
• Multiple Genes : In reality, traits are often influenced by multiple genes, which complicates the stabilization process.

This example illustrates the cubing process used by Nevil Schoenmakers to stabilize a specific genetic trait across multiple generations of backcrossing.

Conclusion