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ESTIMATES OF INTRAGAMETOPHYTIC SELFING AND INTERPOPULATIONAL GENE FLOW IN HOMOSPOROUS FERNS
Author(s) -
Soltis Pamela S.,
Soltis Douglas E.,
Holsinger Kent E.
Publication year - 1988
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 - 10.1002/j.1537-2197.1988.tb11252.x
Subject(s) - biology , gene flow , botany , population , selfing , ecology , biological dispersal , genetic variation , gene , biochemistry , demography , sociology
Relatively little information is available on mating systems and interpopulational gene flow in species of homosporous pteridophytes. Because of the proximity of antheridia and archegonia on the same thallus, it has long been maintained that intragametophytic selling is the predominant mode of reproduction in natural populations of homosporous ferns and other homosporous plants. Furthermore, quantitative estimates of interpopulational gene flow via spore dispersal are lacking. In this paper, we examine five species of homosporous ferns ( Botrychium virginianum, Polystichum munitum, P. imbricans, Blechnum spicant , and Dryopteris expansa ) and present estimates of 1) rates of intragametophytic selling, 2) levels of interpopulational gene flow, and 3) interpopulational genetic differentiation ( F ST ). Our data demonstrate that mating systems vary among species of ferns, just as they do among species of seed plants. The data also suggest that levels of interpopulational gene flow are generally high. The F ST values indicate little genetic divergence among populations for all species except Dryopteris expansa , which exhibits significant levels of interpopulational genetic differentiation. Patterns of genetic diversity in the five species examined are related to the mating system and rate of interpopulational gene flow in each species. The F ST values for all species except Botrychium virginianum are in close agreement with those predicted for an island model of population structure.