hort.net Seasonal photo, (c) 2006 Christopher P. Lindsey, All Rights Reserved: do not copy
articles | gallery of plants | blog | tech blog | plant profiles | patents | mailing lists | top stories | links | shorturl service | tom clothier's archive0
 Navigation
Articles
Gallery of Plants
Blog
Tech Blog
Plant Profiles
Patents
Mailing Lists
    FAQ
    Netiquette
    Search ALL lists
    Search help
    Subscription info
Top Stories
Links
sHORTurl service
Tom Clothier's Archive
 Top Stories
Disease could hit Britain's trees hard

Ten of the best snowdrop cultivars

Plant protein database helps identify plant gene functions

Dendroclimatologists record history through trees

Potato beetle could be thwarted through gene manipulation

Hawaii expands coffee farm quarantine

Study explains flower petal loss

Unauthorized use of a plant doesn't invalidate it's patent

RSS story archive

Crossing with triploids


>Is it possible to make crosses between triploids?

As a general rule triploids have VERY low fertility and pollen is 
usually non-viable.  However, some triploids will show some pod 
fertility.  In the genus Lilium, true lilies for those of you in the 
south where daylilies are often refered to as lilies, there are a lot 
of triploid plants and commerically the triploids are preferred.  Many 
triploid lilies will produce some vuable seeds when pollinated with 
tetraploid pollen and some are a lot more fertile then we would expect 
for a triploid.  Triploid x diploid crosses rarely produce seeds and 
triploid pollen is often unuseable.  My guess is that in hostas you 
will have the best results pollinating triploid hostas with tetraploid 
hostas.  

In lily hybridizing diploids are often pollinated with tetraploids to 
produce triploids and the triploids are then pollinated with 
tetraploids to bring diploid germplasm into the tet germplasm pool.  
This is possible because there is no triploid block that aborts 
triploid embryos.  The result of triploid x tetraploid crosses in 
lilies is almost always tetraploids.

In daylilies we have triploid block, so any triploid embryos that form 
from diploid x tetraploid crosses do not develop.  When you do get 
seeds from diploid daylily x tetraploid daylily they are tetraploid 
because of unreduced gametes on the diploid side.  A diploid normally 
produced haploid gametes, but, because of genetic mutations, some 
plants will produce diploid pollen instead of haploid pollen.  This is 
called unreduced gametes.  

Hostas probably have unreduced gametes because there are natural tet 
species.  However, this is disregarding that hostas are probably 
already ancient amphidiploids.  I don't know how many triploid hostas 
there may be, but I sort of got the impression from Ben's work that 
there are quite a few of them.  This would suggest that triploid block 
may not be present in hostas.  Maybe Ben can fill us in on how many 
triploid hostas there are?

Joe Halinar

Joe Halinar
---------------------------------------------------------------------
To sign-off this list, send email to majordomo@mallorn.com with the
message text UNSUBSCRIBE HOSTA-OPEN





 © 1995-2015 Mallorn Computing, Inc.All Rights Reserved.
Our Privacy Statement
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index