I hadn't hear of the F2 being selfed plants either until it came up
yesterday in an advanced plant genetics course I'm taking. Had a
discussion with prof about it. But this is in plants with both sexes
and in finding new genes in a wild or mutegenticly treated set of
plants. It is not used that way with animals. Just to point out that
terms can be used differently by specialty groups.
Some hybrids cultivar lines (eg corn) are cross of two hybrids, so you
need four 'pure' lines.
The definition of cultivar as line or as a clone depends on what
plant or group you are talking to. For fruit trees, iris, daylilies
etc, it is a clone. Most plants raised from seeds are a line.
Asparagus , which is a perennial, is raised from open pollinated seed
from a planting of same 'cultivar' . No fixed one size fits all.
Chuck Chapman
-----Original Message-----
From: Sean Zera zera@umich.edu [iris-species]
<iris-species@yahoogroups.com>
To: iris-species <iris-species@yahoogroups.com>
Sent: Thu, Feb 5, 2015 10:24 am
Subject: Re: [iris-species] naming irises
That sort of evenly heterozygous F1 hybrid seed is common in vegetables
as well. Frustrating since you can't propagate it yourself without
access to the parents, which will be linebred strains that come true
from seed.
Strains of ornamental fish are often outcrossed to unrelated lines and
then recreated, in order to prevent inbreeding depression. Dogs on the
other hand cannot be registered as purebred (at least in the US) if
their line has ever been outcrossed, even if they're visually
indistinguishable.
I had also never heard that F2s were supposed to be the result of
selfing. Filial generation numbering is commonly used in animal
breeding (laboratory mice, for example), where that couldn't apply.
Sean Z
On Thu, Feb 5, 2015 at 8:04 AM, 'Robert Pries '
robertpries@embarqmail.com [iris-species]
<iris-species@yahoogroups.com> wrote:
Â
Jamie just gave a great summation but I would add one thing about seed
strains. They are not always line-breeding. It is my understanding that
in Petunias for example outcrossing is used regularly to produce a
consistent strain. The two parents may be very different and not
closely related but in some cases their crossing produces about a 99%
consistent result which by the way may be very different from either
parent but constitutes the strain (cultivar).
----------------------------------------------------------
From: "Chuck Chapman irischapman@aim.com [iris-species]"
<iris-species@yahoogroups.com>
To: iris-species@yahoogroups.com
Sent: Wednesday, February 4, 2015 6:49:46 PM
Subject: Re: [iris-species] naming irises
Â
It is the difference between a seed line and a perennial. A perennial
is a 'one off' situation. Seed-line are a family with genetic
traits that are very similar, but still individual variations between
plants.
Along those lines, F2 is technically a self cross, not a cross of
siblings.
Chuck Chapman
-----Original Message-----
From: sdunkley1@bellsouth.net [iris-species]
<iris-species@yahoogroups.com>
To: iris-species <iris-species@yahoogroups.com>
Sent: Wed, Feb 4, 2015 6:41 pm
Subject: Re: [iris-species] naming irises
Help me on a technical point. The lecturing professor's assertion is
certainly one of those huh? moments that always come up in a good
discussion of cultivar. I have to assume the man is exquisitely
correct. Registering a cultivar with the AIS appears to the encouraged
protocol for introducing one's iris to the community. If one wants the
cultivar to remain genetically synonymous with a certain clone, how
might one go about this? For discussion's sake, how could it be done
strictly within the current protocol? If we need to discuss changes of
protocol, do that after exhausting the "no changes" options.
--
Bob Pries
Zone 7a
Roxboro, NC
(336)597-8805
