|
|
||||||||
American Journal of Botany, Vol 84, 1664, Copyright © 1997 by Botanical Society of America, Inc.
POPULATION BIOLOGY |
EA Hooper and CH Haufler
Epiphytes are ecologically important components of tropical forests worldwide and yet they have been underrepresented in studies of reproductive biology. Given the presumed ephemeral nature of their substrates, and the importance of dispersal and colonization, epiphytes might be expected to undergo substantial inbreeding to ensure reproductive success, as in weedy terrestrial plants. While there is some evidence for inbreeding in epiphytic angiosperms, the only previous studies of fern epiphytes indicate that they are predominantly outcrossing. The present study reports on the genetic diversity and breeding system of six members of the Neotropical epiphytic fern genus Pleopeltis (Polypodiaceae). A survey of isozyme variability using starch gel electrophoresis revealed high population levels of polymorphism (P = 0.62), allelic diversity (A = 2.3), and individual heterozygosity (Ho = 0.181), but little differentiation among conspecific populations (I ³ 0.98; Gst = 0.048), and high interpopulational gene flow rates (Nm > 1). In addition, there was no indication of homozygote excess within populations that might indicate a history of selfing in these ferns: populations generally conformed to Hardy-Weinberg expected genotype frequencies, and both Wright's inbreeding coefficient (Fis) and Holsinger's intragametophytic selfing rates approached zero. Possible mechanisms limiting inbreeding in these ferns include antheridiogen activity and high levels of genetic load that would lead to inbreeding depression upon selfing.
This article has been cited by other articles:
![]() |
I. Avila-Diaz and K. Oyama Conservation genetics of an endemic and endangered epiphytic Laelia speciosa (Orchidaceae) Am. J. Botany, February 1, 2007; 94(2): 184 - 193. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. GONZALEZ-ASTORGA, A. CRUZ-ANGON, A. FLORES-PALACIOS, and A. P. VOVIDES Diversity and Genetic Structure of the Mexican Endemic Epiphyte Tillandsia achyrostachys E. Morr. ex Baker var. achyrostachys (Bromeliaceae) Ann. Bot., October 1, 2004; 94(4): 545 - 551. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. S. Lott, J. C. Volin, R. W. Pemberton, and D. F. Austin The reproductive biology of the invasive ferns Lygodium microphyllum and L. japonicum (Schizaeaceae): implications for invasive potential Am. J. Botany, August 1, 2003; 90(8): 1144 - 1152. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Pajaron, E. Pangua, and L. Garcia-Alvarez Sexual expression and genetic diversity in populations of Cryptogramma crispa (Pteridaceae) Am. J. Botany, July 1, 1999; 86(7): 964 - 973. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |