What happens with population genetics (each breeding line is it's own
population) is loss of variation on a number of genes. Referred to as
Inbreeding depression. There are formula for calculating this in plant
and animal breeding. During this process secondary traits such as
germination, branching (cold hardiness) etc can loose some of its
variability and get trapped into a restriction. This can only be broken
by crossing into a line that does not have this problem, and selecting
carefully on this trait.
So, for example, inbred pink lines can end up with a trait which
requires less vernalization for germination. But when lines are
crossed, these traits will become less distinct.
While some traits can be located close to others, and be linked, in
this situation, this is a less likely scenario, although possible.
The tangerine factor, for instance, has been noted , by you, as
needing less vernalization for germination. Likely a variability
selected out. So if linked, a group of seedlings having some
tangerine factor and some not having ( as in example being addressed),
the tangerine factor seeds would germinate faster ,and be more
represented in first year germination, rather then in second year
germination. The opposite of what was reported.
Then we have to look at math. Probabilities and distribution curves.
That is all offspring of a cross will be on a distribution curve. With
a mean and a standard deviation, for all traits involving multiple
genes. For example petal width, petal size, petal strength. So when
one group of seedlings has one set of means and SD, different then a
separate set, then probability of being samples from same population
set becomes extremely low.
So you are not going to get a set of poor seedlings for one year
(one sample set) and a set of good seedlings in second year (second
sample set), by random. If we are looking at possible genetic linkage,
then there would have to be linkage of tangerine factor, and multiple
genes associated with substance and petal size linked with each other
and with germination factors, such as vernaliztion genes. Sorry, a
very improbable situation.
From: Linda Mann <email@example.com>
To: iris-photos <firstname.lastname@example.org>
Sent: Fri, May 25, 2012 6:34 am
Subject: [iris-photos] re: HYB: 2nd year sprouts
Like I said, may just be coincidence of original source of, for
pinks also just happening to be ones that germinate early (lower temps)
and with little chilling.
Chuck, no reason lots of unrelated traits might be on the same
chromosomes, right? Then they would track together until/unless a
crossover of some sort.
So maybe some of the progenitors of various colors/patterns/form of our
modern TBs just happened to have germination traits on the same
chromosome(s) as some of the colors/patterns.
Snow Flurry, May Hall, etc
Like this helps us any in reaching our goals. ;-)
Linda Mann east TN USA zone 7b