論文

査読有り
2011年11月

Reticulate evolution in the Crepidomanes minutum species complex (Hymenophyllaceae)

AMERICAN JOURNAL OF BOTANY
  • Joel H. Nitta
  • ,
  • Atsushi Ebihara
  • ,
  • Motomi Ito

98
11
開始ページ
1782
終了ページ
1800
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.3732/ajb.1000484
出版者・発行元
BOTANICAL SOC AMER INC

Premise of the Study: Hybridization is an important mechanism of speciation in plants and often results in complexes that comprise multiple sexual diploids and their hybrid offspring. However, the intricacy of these systems has prevented a thorough understanding of many groups. The Crepidomanes minutum species complex (Hymenophyllaceae) is a widely distributed, morphologically variable fern species complex. Although prior reports of apogamy and polyploidy suggest hybridization, it has never been the focus of a phylogenetic study.Methods: Morphology, nuclear (gapCp), and chloroplast (rbcL) DNA sequences, cytology, field observation, and spore counts were used to infer phylogeny and trace hybrid origins.Key Results: The C. minutum species complex is composed of at least three major clades: the African clade, clade 1 (East Asia and the Pacific), and clade 2 (Southeast Asia and the South Pacific). Clades 1 and 2 differ strikingly in morphological variation (uniform in clade 1 vs. highly variable in clade 2) and occurrence of hybrids (rare in clade 1 vs. frequent in clade 2). Apogamy and polyploidy were confirmed as likely mechanisms of hybrid stabilization in clade 2. Despite the large genetic distance between clades 1 and 2, several specimens were observed with gapCp sequences from both; diploid genome size and sexual reproduction indicate maintenance of genetic diversity via introgression or incomplete lineage sorting, rather than ongoing hybridization, in these specimens.Conclusions: The C. minutum species complex is a reticulate network including multiple diploid lineages and their stabilized hybrid crosses. Additional sampling focused on reproductive mode and ploidy level is needed to delimit diploid species and hybrids.

Web of Science ® 被引用回数 : 37

リンク情報
DOI
https://doi.org/10.3732/ajb.1000484
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000296760500017&DestApp=WOS_CPL
ID情報
  • DOI : 10.3732/ajb.1000484
  • ISSN : 0002-9122
  • Web of Science ID : WOS:000296760500017

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