Clonal structure of wild populations and origins of horticultural stocks of Illicium parviflorum (Illiciaceae)

Department of Biology, University of South Alabama, Mobile, Alabama 36688 USA.
American Journal of Botany (Impact Factor: 2.6). 09/2010; 97(9):1574-8. DOI: 10.3732/ajb.0900291
Source: PubMed


• Premise of the study: Habitat fragmentation is often assumed to result in limited genetic diversity across impacted plant communities. Central Florida has undergone extensive anthropogenic changes, while also harboring large numbers of endemic species. In this study, we assessed genetic structure and dependence on clonality in a central Florida endemic, Illicium parviflorum (Illiciaceae), as well as evaluated genetic diversity of this species in horticultural stocks. • Methods: Six sites were sampled across the geographic range of I. parviflorum. A PCR-based assay using intersimple sequence repeats (ISSRs) was used to assess genetic structure. • Key results: Results, based on 26 ISSR loci, suggest that clonal structure plays a role in all populations, with PD values ranging from 0.25 to 0.50. Only two populations exhibited unique genotypes, while the remaining four populations shared genotypes. Horticultural samples all shared one genotype, which can be traced back to a single natural population. • Conclusions: Clonal reproduction is an important factor in the maintenance of natural populations of I. parviflorum, although the degree to which this is true varies by population. Horticultural samples likely represent a single or very few collection events, indicating the need for greater genetic diversity within horticultural stocks. Further analyses using microsatellites are planned to confirm these results.

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Available from: Ashley B Morris, Jul 30, 2014
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    ABSTRACT: Plant life history traits like clonal growth and dioecy can complicate endangered species conservation because of the potential for remnant populations to contain few genetically different individuals or a single sex. In this study, we used 11 microsatellite (SSR) markers to characterize fine-scale genetic structure of the endangered dioecious perennial Lindera melissifolia (pondberry) growing in seasonally isolated wetlands across the southern Atlantic Coastal Plain. We found fine-scale genetic structures consistent with extensive clonal growth in all sites. Of the 508 stems sampled across 11 sites, we found 67 genetic individuals (genets), of which 94% were site specific and 39% were represented by a single stem. Individual sites contained from 1 to 16 genets. Spatial genetic analyses showed limited intermingling among different genets within sites, which is consistent with a phalanx clonal growth form. Nine of the eleven sites had biased sex ratios, with six male and three female biased sites. Given our observations of extensive clonal growth, few genetic individuals, and biased sex ratios, we conclude that simple stem counts of this clonal perennial dioecious shrub will grossly overestimate the number of genetic individuals in these remnant southern Atlantic Coastal Plain sites. In order to promote self-sustaining sexually reproducing pondberry populations, as outlined in the pondberry recovery plan, natural areas managers may want to consider introducing unrelated and underrepresented gender plants into sites with few genets or biased sex ratios.
    Full-text · Article · Apr 2013 · Journal of the Torrey Botanical Society