English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Polyploidization is a major mechanism of speciation in plants. Within the barley genus  Hordeum , approximately half of the taxa are polyploids. While for diploid species a good hypothesis of phylogenetic relationships exists, there is little information available for the polyploids (4×, 6×) of  Hordeum . Relationships among all 33 diploid and polyploid  Hordeum  species were analyzed with the low-copy nuclear marker region  TOPO6  for 341  Hordeum  individuals and eight outgroup species. PCR products were either directly sequenced or cloned and on average 12 clones per individual were included in phylogenetic analyses. In most diploid  Hordeum  species  TOPO6  is probably a single-copy locus. Most sequences found in polyploid individuals phylogenetically cluster together with sequences derived from diploid species and thus allow the identification of parental taxa of polyploids. Four groups of sequences occurring only in polyploid taxa are interpreted as footprints of extinct diploid taxa, which contributed to allopolyploid evolution. Our analysis identifies three key species involved in the evolution of the American polyploids of the genus. ( i ) All but one of the American tetraploids have a  TOPO6  copy originating from the Central Asian diploid  H. roshevitzii , the second copy clustering with different American diploid species. ( ii ) All hexaploid species from the New World have a copy of an extinct close relative of  H. californicum  and ( iii ) possess the  TOPO6  sequence pattern of tetraploid  H. jubatum , each with an additional copy derived from different American diploids. Tetraploid  H. bulbosum  is an autopolyploid, while the assumed autopolyploid  H. brevisubulatum  (4×, 6×) was identified as allopolyploid throughout most of its distribution area. The use of a proof-reading DNA polymerase in PCR reduced the proportion of chimerical sequences in polyploids in comparison to  Taq  polymerase.

Progenitor-Derivative Relationships of Hordeum Polyploids (Poaceae, Triticeae) Inferred from Sequences of TOPO6, a Nuclear Low-Copy Gene Region