Re: ploidy
Ben:
>An example is a 1 to 3 splitting of Snow Flakes flower colour in the
>F2. This would not be possible if the plants were polyploid.
You may be intelligent about yeast and fungus and maybe even fruit fly
genetics, but in one of my last messages I wondered if you knew what
an amphidiploid was. It is obvious from your above statement about
polyploids not being able to have a 3:1 ratio that you don't know what
a amphidiploid is. You obviously don't know Mendelain genetics.
If you have an amphidiploid tetraploid hosta of genotype Aa//aa where
the // seperates the two genomes then you get a 3:1 segeration because
your gametes are either Aa or aa. The chromosomes from the two
different genomes don't pair. Chromosome #1 of genome N pairs with
chromosome #1 of genome N, but does not pair with chromosome #1 of
genome M. I just made up the N and M genomes, so they have no
significence to reality.
However, if the genotype is AA//aa then 100% of the selfed progenies
will be of the dominant A phenotype because the gametes are all Aa
(maybe I should write that as A//a). This is called fixed
heterozygosity.
Ben, you need to read a good book on Mendelian genetics and segeration
ratios.
Joe Halinar
---------------------------------------------------------------------
To sign-off this list, send email to majordomo@mallorn.com with the
message text UNSUBSCRIBE HOSTA-OPEN
