I would be willing to bet that siberica isn't really closer to
pseudacorus than to other Sibericae. Given the identical chromosome
number, fertility of hybrids and similar morphology of
siberica/sanguinea/typhifolia, it seems unlikely they're not related.
That said, according to Wilson's tree, the siberians and
sino-siberians are quite closely related to pseudacorus and company
anyways, so crosses between any of the species are surely worth trying.
In a diploid cross between different species, the chromosomes may not
be able to pair up, causing assorted problems from infertility to
total non-viability. This is especially likely when the chromosome
counts differ. Since a tetraploid parent contributes two of each
chromosome instead of one, they can pair with themselves in the
offspring instead of with the other parent's chromosomes, avoiding
this problem. The resulting offspring may essentially be a new diploid
species with a higher chromosome number.
Although it limits the hybridizer, I actually like the idea of sterile
hybrids as garden plants, as a way to avoid introducing invasive
species.
Sean Z
Quoting g*@sasktel.net:
> Now this is all very fascinating information for one who likes to do
> some hybridizing! Canât wait to give it a try myself. Also, will
> look forward to seeing this hybrid seedling flower as well.
> I do have a question regarding the use of the tetraploids â why
> would this work any better than using both diploids? Also, it is
> interesting that if siberica and sanguinea are not closely related
> that the offspring from such a cross as still quite fertile??
> Jim in Saskatoon
>
> From: Rodney Barton
> Sent: Friday, March 04, 2011 4:12 PM
> To: i*@yahoogroups.com
> Subject: Re: [iris-species] I. sibirica X I. pseudacorus
>
>
>
> My understanding is that Siberian Irises, as a class, are mostly I.
> sanguinea. A surprising finding by Dr. Wilson is that I. sanguinea
> is not very closely related to I. sibirica.
>
> Rod
>
>
>
>
> ----------------------------------------------------------
> From: JamieV. <j*@freenet.de>
> To: i*@yahoogroups.com
> Sent: Fri, March 4, 2011 3:54:21 PM
> Subject: Re: [iris-species] I. sibirica X I. pseudacorus
>
>
> Dennis, et al,
>
> I've tried the cross a few times with no takes, but using
> tetraploids should most certainly work creating an amphidiploid.
> There are quite a few tet sibericas to try. Sultan's Ruby comes to
> mind as being a very reliable garden plant. Dennis, could you send
> over some of the tetraploid pollen? I have SR and a couple of other
> tetraploids in the garden. This may be worth a try.
>
> Jamie
>
> Am 04.03.2011 22:47, schrieb Dennis Kramb:
>
> I grow both. I can try it this year (if you remind me!).
> Actually my clone of pseudacorus is tetraploid, so that could
> improve chances of a successful cross.
>
> Dennis in Cincy
>
>
>
>
>
> -- Jamie V._______________________KÃln (Cologne)GermanyZone 8
>
>
