phenotypes for beginners

[stinkyattic]

Genotypes of your plant will determine all possible phenotypes. Genotypes are the genetic information your plant receives from its parents. It seems to me that most of what people refer to as "phenotype stabilizing" is just selective breeding.

For each trait, there are 2 possible genes, a dominant and a recessive. Combined, there are 3 possible combinations, homozygous dominant expressing the dominant trait, heterozygous expressing the dominant trait also but carrying the potential for recessive in the next generation, and homozygous recessive, expressing the recessive trait. These 3 genotypes are visible as only 2 phenotypes.

The grower just looks for the plants with the best of all traits .... The overall point is to remove as many recessive genes out of the pool as possible.

This is actually incorrect. For example, purple bud is not a dominant trait but it is highly deisrable to breeders, and if you take a recessive gene for purple bud (g) whose dominant counterpart is green bud (G) we will see these possible combos:
GG= green bud
Gg, gG= green bud
gg= purple bud
The trick is to cross the heterozygous ones- simply, you can allow random mating in a large population and see about 25% of the plants show purple bud; those are homozygous recessive and show the phenotype of a trait you WANT.
Don't confuse recessive and undesirable.

This is where things really get less clear. So I think we can assume that even the best selective breeding is only so effective. I doubt you can ever totally isolate recessive traits.

You can, it is done often, and it just takes a little working knowledge of genetics.

It's also well known that environmental factors can influence phenotypes. ... So it stands to reason that even the most stable of phenotypes can be made less stable due to these changes.

Potential for expressing a vertain trait is genetic (for example a plant that turns purple in cold temps). The environmental factors simply allow or prevent expression of a certain trait.
Here I think you are misusing the term 'phenotype'... a stable STRAIN - let's think of it as an isolated population for argument's sake- can show different expressed traits under different conditions. A phenotype is just a distinct set of traits common to certain individuals within that population.

Anyway hopw that sorta helps.

stinkyattic Reviewed by stinkyattic on 06-21-2007. phenotypes for beginners I'm still a beginner myself, but I've been a little confused about the way people use the term phenotypes when talking about seed suppliers. So I did some research for myself and wanted to share. If any experts would help me along or correct any bad information I would be grateful for that. So lets start with the most obvious question. What is a phenotype? Boiled down to an overly simple answer it's basically any distinct trait about an organism you can observe and classify. This Rating: 5