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Random amplified polymorphic DNA markers to study clonal diversity in different aged populations of Ammophila breviligulata

Stephen Paul Bush, University of Massachusetts Amherst

Abstract

The analysis of the colonization and development of communities on islands, or the Theory of Island Biogeography, predicts an initial increase of species upon newly exposed islands. However, as the extent of species invasion increases, species extinction also increases. Eventually, an equilibrium is reached where species recruitment is balanced by species extinction. To investigate whether genetic change within clonal plant populations parallels community development upon islands, this study investigated genetic diversity in different-aged populations of Ammophila breviligulata. Results from previous studies of Ammophila breviligulata have yielded conflicting conclusions. Laing found sexual reproduction to be infrequent in mature populations of A. breviligulata, and, therefore, suggested that genetic diversity must decrease as A. breviligulata populations age. In three different aged populations of A. breviligulata, Carlson, using isozymes, found that the number of genotypes per population increased with increasing population age. Using RAPDs, I determined genetic diversity in four young (between two and six years) and four old populations (greater than one-hundred years) of A. breviligulata. Young populations contained an intermediate number of genets, while old populations varied in clonal diversity. Populations of A. breviligulata examined in this study were founded by a diversity of propagules. However, sexual reproduction and vegetative immigration may be limited in some older populations, and thus the lack of continual recruitment in A. breviligulata populations may cause departures from the assumptions of the island colonization model. Alternatively, sporadic sexual reproduction may occur in some older populations, and clonal diversity could thus be maintained or increased over time, as was found in one population of this study. The variance in the number of genets within old A. breviligulata populations indicates that genetic diversity in different aged populations is not correlated with predicted community changes on islands. RAPDs may be useful in identifying genets in natural populations, since similar patterns of clonal diversity were detected within populations by both RAPDs and isozymes, although RAPDs detected a somewhat greater number of genets. Somatic mutation within genets may possibly be detected by RAPDs and isozymes.

Subject Area

Ecology|Genetics|Botany

Recommended Citation

Bush, Stephen Paul, "Random amplified polymorphic DNA markers to study clonal diversity in different aged populations of Ammophila breviligulata" (1996). Doctoral Dissertations Available from Proquest. AAI9709578.
https://scholarworks.umass.edu/dissertations/AAI9709578

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