Re: HYB: Diploid - Tetraploid

Thanks Neil,

Any little bit of information is always  helpful - I'm just trying to learn
and these two terms kept cropping up in the list and the dictionary didn't
help me at all.  I found diploid, but could not find tetraploid.  

Diploid =  twice the number of chromosomes normally in a germ cell.   
Tetra = a combining form meaning four - -  I suppose this means 4 times the
number of chromosomes 

Until I took the time to look definitions up, I had thought these terms
were referring to the type of iris that had been crossed.

I suppose this means that someone has dissected the iris seeds (germ cell)
and/or pollen to determine how many chromosomes they have.   If my
highschool biology covered this type of analysis, I've forgotten what it
was.  I certainly didn't expect to find it crop up in hybridization of
iris.  

Mickey Corley
Bethany, OK - Center of Oklahoma USA
Zone 6/7


Message text written by INTERNET:iris@hort.net
>"Neil A Mogensen" <neilm@charter.net>

For modern TB sorts, you can safely assume they are all tetraploid.  If you
were to go to Lowell Baumunk's catalog or website and look at bearded
species,
you can assume they are diploid unless either there is a notation, or you
have
information from some source such as *The World of Irises* that says the
wild,
collected sort is tetraploid.  For example, all the aphylla clones are
tetraploid.

For beardless, the catalogs will usually tell you for Siberian and JI
irises.
Very few LI are tetraploid, but they will be described as such as well.

The table iris are usually diploid unless they are from Markham or from Jim
and Vicki Craig, with aphylla ancestry reducing the proportions of TB's and
BB's to table or near-table size but retaining the tetraploid status. 
Catalog
descriptions often will specify.

In general, tetraploids have larger pollen grains, thicker and heavier
stems,
larger flowers, heavier substance and slower growth than a parallel or
related
diploid.

I hope this is helpful or useful.

Neil Mogensen  z6b/7a near Asheville/Hendersonville, NC  (did someone
suggest
building an ark?)

---------------------------------------------------------------------
To sign-off this list, send email to majordomo@hort.net with the
message text UNSUBSCRIBE IRIS
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index