RE: hybridizing questions was Attention -- Class of '97
- To: Multiple recipients of list <i*@rt66.com>
- Subject: RE: hybridizing questions was Attention -- Class of '97
- From: S* M* <7*@compuserve.com>
- Date: Wed, 14 Jan 1998 09:57:44 -0700 (MST)
Maureen Mark wrote:
> What genes are involved with "red" and "black" irises? =
"Red" is a complicated issue. =
Werckmeister wrote of some =
interesting tests concerning the
pigments.
In a practical sense, the true red
pigment remains elusive and the
"reds" we have are either reddish-
violet or reddish-brown. Both are
seem to involve multiple series of
alleles,a dosage effect, and [perhaps]
modifiers.
"Black" is similar -- they can be a =
bluish-black, a reddish-black, or
a brownish-black. =
Either of these complex families
would be a good study subject that
could lead to worthwhile experiments.
> Are these
> colours dominant?
That's not a yes/no question [see
above] but some component traits
are dominant.
> Is purple based foliage a dominant trait? =
Yes.
> Any chance that someone might
> have the time and resources to put together a comprehensive list of
> known dominant and recessive traits?
I've been collecting source material
on this subject for over 20 years, but
I wouldn't describe it as comprehensive.
> The plicata gene is recessive but also carries other recessive traits
> such as glaciatas, luminatas and broken colours. These have been
> written up in past AIS bulletins. Are there other recessive genes that=
> might have the same potential?
Definitely. A trait is dominant or recessive
with respect to something else. Eliminate
the dominant allele of a series and lower
level recessives may show themselves.
I haven't studied Barry Blythe's red-blacks
from amoena lines in depth, but they might
be an example of this phenomenon.
> On line-breeding, how many generations can be pursued without weakenin=
g
> the line, i.e., when should backcrosses and outcrosses be carried out.=
> I know that this will vary for the types of lines being pursued but a
> rule of thumb would be helpful.
A very interesting question. I can't suggest
a number from personal experience because
outcrossing is an integral part of my program.
I can report, though, that the percenatage of
vigorous plants from out-crossing has been
no better [and sometimes much worse] than
those obtained from line-breeding. But I think =
that is more reflective of my selection process
than descriptive of the genetic potential.
Sharon McAllister
73372.1745@compuserve.com
