If chromosomes are so incompatible as to not be able to pair up to
give a viable species, they can't do it. Two sets of chromosomes
can't pair with two other sets of incompatible chromosomes any better.
Where the difference comes in is that if an incompatible set is able to
pair up , produce a viable offspring,. this organism isn't able to form
gametes from meiosis and so is sterile. If there are two sets, there is
an amphidiploid and pairing and formation of viable gametes is
possible.
Tetraploidy is a solution for sterility, not for viability.
Chuck Chapman
-----Original Message-----
From: Dennis Kramb <dkramb@badbear.com>
To: iris-species <iris-species@yahoogroups.com>
Sent: Tue, Jan 7, 2014 3:09 pm
Subject: Re: [iris-species] Re: inducing tetraploidy
Â
Chuck, perhaps I've misunderstood, but I thought the theory was if two
wide species won't cross as diploids, they might as tetraploids. (For
example, Little Caillet.)
Regardless, I'm going to attempt conversions on:Â tridentata, fulva,
prismatica, and tectorum. And possibly: wilsonii, and black
chrysographes if I can find them.
The Oryzalin technique I'm going to follow had approx 10% success rate
with Watsonia sp.
Thanks to everyone for the tons of feedback & support I got on this
endeavor.
Dennis in Cincinnati
On Mon, Jan 6, 2014 at 9:55 AM, Chuck Chapman
<irischapman@aim.com> wrote:
Tetraploids are often (usually) fertile. ÂDiploids are never fertile on
wide crosses. If tertraploids set seed, then so will diploids. ÂIf the
diploid corosses don't set seed, then the genes don't match up well
enough and having tetraploids Âis very unlikely to make a difference.
If you make a diploid cross and get seeds, it is easy to treat seeds at
time of germination and get tetraploids. MMuch easier to treat
germinating seeds then converting a plant.
Chuck Chapman
