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

Re: EVOLUTION OF HOSTAS


 Thanks George.  I understoood a good part of that.

Chick

W. George Schmid wrote:

  Chick
  There is no fossil evidence as of now.
  
  Cytologists found Hosta to be karyotypically similar to Yucca, Agave,
  Camassia and other genera so, principally on cytological grounds, it was
  proposed to include Hosta with the Agavaceae and evidence for this and
  similar placements was provided by a number of researchers. Embryological
  information based on serology found support among cytologists, but because
  karyotypical similarities appear to be common among plants formerly placed
  in the Liliaceae, however placements based on cytological evidence alone are
  no longer considered conclusive.
  
  Analysis of the divergent morphologies of the original populations in Japan,
  Korea and China reveals that Japan is not the evolutionary birthplace of the
  genus, since the native Japanese species are morphologically quite uniform
  when regarded in a broad sense. Palynological (pollen) evidence indicates
  that the progenitor of Hosta may have been lily-type ancestors from which H.
  plantaginea evolved and an evolutionary trend can be seen in the developing
  pollen types from reticulate through rugulate or rugulate-baculate to
  rugulate-granulate type. I believe this trend is also seen in the
  variability of macromorphological characters when correlated to geographic
  location and environment.
  
  Predecessors of the genus probably migrated from the east-central Chinese
  mainland, where the most ``primitive'' hosta still exists (H. plantaginea),
  through southern Manchuria into the Korean peninsula and via this southern
  route to southern Japan. The northern route extended along the coast of the
  south-eastern USSR following a path on the southern side of the Sikhote-Alin
  mountain range and migrating to Sakhalin and from there south into Hokkaido
  and Honshu. The main Japanese islands providing a climatologically and
  ecologically very diverse habitat gave rise to increased speciation. I
  believe that the taxa growing in northern Kyushu (H. tibai), on Tsushima
  Island (H. tsushimensis) and the southernmost islands of Korea (H. jonesii)
  may have originated with the northern branch of evolution, while all other,
  highly differentiated Korean taxa originated with the southern evolutionary
  branch after becoming geographically isolated in insular Korea and it was
  only through geographic isolation that these species remained distinct.
  
  On the main Japanese islands natural, proximal populations probably have
  been hybridizing and intergrading for centuries. Hybridization is usually
  assumed to take place between completely divergent species but this may not
  be totally correct because it assumes that the two hybridizing stocks are
  composed of individuals which have gone through past complete divergence,
  i.e. they evolved over centuries with the attendant production of a
  reproductive barrier. The Chinese night-blooming H. plantaginea and
  day-blooming Japanese and Korean species are reproductively isolated from
  each other morphologically, this barrier can be easily overcome by human
  intervention.
  
  Phylogenetically, close affinity with Agave, Camassia, Hemerocallis,
  Hesperocallis, Leucocrinum, Manfreda and Yucca have been suggested which has
  created rather numerous phylogenetic placements, each one having its
  proponents so there is no real agreement on the phylogeny of Hosta.
  
  H. venusta, for example is less than 15,000 years old. The propagules of H.
  venusta were moved from southeastern Korea to Cheju Island after the last
  ice age. The geological age of Cheju Island is estimated to be 13,000 years
  so H. venusta found only on this island must have speciated after the
  volcanic island became habitable. During the process of adapting to a new,
  hostile, basaltic island habitat of recent origin, H. venusta underwent
  subsequent genetic changes. It was determined that 49 enzyme bands of H.
  venusta are a subset of 72 bands found in H. minor so establishing a very
  close relationship and making H. minor the starting point for H. venusta.
  
  Since there are no hostas native in North America but many other Asian
  species crossed the land bridge it can be assumed that hostas must have
  evolved after the Bering land bridge disappeared.
  
  A lot of this is supposition, but there is evidence for many of the
  opinions, including mine. George
  
  W. George Schmid
  Hosta Hill - Tucker Georgia USA
  Zone 7a - 1188 feet AMSL
  84-12'-30" West_33-51' North
  Outgoing e-mail virus checked by NAV
  ----- Original Message -----
  From: "Chick"   <chick@bridgewoodgardens.com>  To:   <hosta-open@hort.net>  Sent: Wednesday, September 01, 2004 4:17 PM
  Subject: EVOLUTION OF HOSTAS

    I once read, I think in an article by Bob Solberg, that hostas, being
    monocots, are rather primitive plants, evolutionarily speaking.  George
    Schmidt said recently that there is no fossil evidence that the plant is
    very old, again evolutionarily speaking.
    
    Where do hostas come from?
    
    Chick
    
    ---------------------------------------------------------------------
    To sign-off this list, send email to     majordomo@hort.net     with the
    message text UNSUBSCRIBE HOSTA-OPEN

  ---------------------------------------------------------------------
  To sign-off this list, send email to   majordomo@hort.net   with the
  message text UNSUBSCRIBE HOSTA-OPEN

---------------------------------------------------------------------
To sign-off this list, send email to majordomo@hort.net 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