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Natural hybridization in tropical spikerushes of Eleocharis subgenus Limnochloa (Cyperaceae): Evidence from morphology and DNA markers
Author(s) -
Košnar Jan,
Košnar Jiří,
Herbstová Miroslava,
Macek Petr,
Rejmánková Eliška,
Štech Milan
Publication year - 2010
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.3732/ajb.1000029
Subject(s) - biology , subgenus , hybrid , sympatric speciation , population , evolutionary biology , botany , genetics , taxonomy (biology) , demography , sociology
• Premise of the study: Natural hybridization represents an important force driving plant evolution and affecting community structure and functioning. Hybridization may be overlooked, however, among morphologically highly uniform congeners. An excellent example of such a group is Eleocharis subgenus Limnochloa , which has no reliably proven hybrids. Does this reflect biological barriers to interspecific crosses or difficulties in detecting the hybrids? We tested the hypothesis that hybridization occurs among sympatric Eleocharis cellulosa , E. interstincta , and E. mutata in northern Belize, Central America. • Methods: Morphometric study (407 plants) was followed by examination of inter‐simple sequence repeat (ISSR) polymorphisms (44 plants) and ITS sequence variation (33 plants). • Key results: Two putatively hybrid morphotypes were discerned— E. cellulosa ‐resembling and E. interstincta ‐resembling. DNA markers of E. cellulosa and E. interstincta displayed additive constitution in plants from one E. cellulosa ‐resembling population only. The other putatively hybrid populations contained ISSR and ITS markers of the species they resembled morphologically, several unique ISSR markers, and ITS sequences of an undescribed South American Limnochloa entity. DNA markers of E. mutata were absent in the putative hybrids. • Conclusions: Simultaneous use of various types of molecular markers can overcome many pitfalls of investigations concerning hybridization among closely related and morphologically similar species. Northern Belize represents a hybrid zone of E. cellulosa and E. interstincta . A third participant in the hybridization events occurring in this zone is an unknown Limnochloa lineage but is not E. mutata . Interspecific hybridization may play a significant role in the diversification of Eleocharis .