Re: naming irises

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We were talking of use of terms, and how in certain groups (ie;
horticulturists versus geneticists) meaning of terms can be defined
differently . This (F2) was brought up as an example of a different
definition of a term in a specialist group, similar to how cultivar
is defined differently by different groups.

The term F2 for molecular plant geneticists is defined differently
then for plant or animal breeders Animal breeders can only use sib
crosses. Plant breeders can use sib or self. But molecular plant
breeders use self crosses for F2. The reason for this, is a lot of the
studies are on induced mutations. And much of it with Arabidopsis for
a number of reasons, including that it has only two cells in seed
(keep track of this fact). To study the function of genes you need
to get a mutant or non functioning gene. The vast majority of genes
don't have a non functioning mutant, so they have to be created. This
can be done with Arabidopsis seed by radiation or chemical treatment.
When they do get a mutant, it is in only one of the two cells in the
seed. So in F1 half of the plants will get the mutant and half
not. So, to get a recessive mutant gene expressed it has to be a
selfed cross as it is too hard to get it from sib crosses, as only
half of them have it. Too random. Unlike normal F1 were all siblings
can carry gene.

A specialized definition.

Six decades of genetic experience/learning and still learning many
new things in genetics every day. Almost none of molecular genetics
tools currently in use even existed 60 years ago. New tools all the
time.

Chuck Chapman


-----Original Message-----
From: Walter Pickett w*@... [iris-species]
<i*@yahoogroups.com>
To: iris-species <i*@yahoogroups.com>
Sent: Sat, Feb 7, 2015 2:46 pm
Subject: Re: [iris-species] naming irises