Ania M. Wieczorek

Super-Genotype: Global Monoclonality Defies the Odds of Nature

The ability to respond to natural selection under novel conditions is critical for the establishment and persistence of introduced alien species and their ability to become invasive. Here we correlated neutral and quantitative genetic diversity of the weed Pennisetum setaceum Forsk. Chiov. (Poaceae) with differing global (North American and African) patterns of invasiveness and compared this diversity to native range populations. Numerous molecular markers indicate complete monoclonality within and among all of these areas (FST = 0.0) and is supported by extreme low quantitative trait variance (QST = 0.00065–0.00952). The results support the general-purpose-genotype hypothesis that can tolerate all environmental variation. However, a single global genotype and widespread invasiveness under numerous environmental conditions suggests a super-genotype. The super-genotype described here likely evolved high levels of plasticity in response to fluctuating environmental conditions during the Early to Mid Holocene. During the Late Holocene, when environmental conditions were predominantly constant but extremely inclement, strong selection resulted in only a few surviving genotypes.

Permanent Genetic Resources added to Molecular Ecology Resources Database 1 June 2010 - 31 July 2010.

This article documents the addition of 205 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Bagassa guianensis, Bulweria bulwerii, Camelus bactrianus, Chaenogobius annularis, Creontiades dilutus, Diachasmimorpha tryoni, Dioscorea alata, Euhrychiopsis lecontei, Gmelina arborea, Haliotis discus hannai, Hirtella physophora, Melanaphis sacchari, Munida isos, Thaumastocoris peregrinus and Tuberolachnus salignus. These loci were cross‐tested on the following species: Halobaena caerulea, Procellaria aequinoctialis, Oceanodroma monteiroi, Camelus ferus, Creontiades pacificus, Dioscorea rotundata, Dioscorea praehensilis, Dioscorea abyssinica, Dioscorea nummularia, Dioscorea transversa, Dioscorea esculenta, Dioscorea pentaphylla, Dioscorea trifida, Hirtella bicornis, Hirtella glandulosa, Licania alba, Licania canescens, Licania membranaceae, Couepia guianensis and 7 undescribed Thaumastocoris species.

Isolation and characterization of polymorphic microsatellite markers from the velvet tree, Miconia calvescens DC. (Melastomataceae).

Nine polymorphic microsatellite loci were isolated and characterized from the invasive velvet tree (Miconia calvescens DC.), a serious forest invader in tropical Pacific oceanic islands. These loci provided markers with polymorphism of three to 10 alleles per locus within 95 individuals. The expected and observed heterozygosities ranged from 0.0367 to 0.5053 and from 0.0370 to 0.2473, respectively. These markers should be useful to study dispersal and the invasion genetics of the velvet tree.

Invasive congeners are unlikely to hybridize with native Hawaiian Bidens (Asteraceae)

UNLABELLED PREMISE OF THE STUDY Invasive plant species threaten native plants in multiple ways, one of which is genetic assimilation through hybridization. However, information regarding hybridization between related alien and native plant species is generally lacking. In Hawaii, the invasive Central American species Bidens pilosa and Bidens alba have colonized natural areas and often grow alongside the native Hawaiian Bidens species, a clade representing an adaptive radiation of 27 endemic taxa, many of which are threatened or endangered. • METHODS To assess the risk of hybridization between introduced and native Hawaiian Bidens (which will readily hybridize with one another), we undertook crosses in cultivation between the invasive species and nine native Bidens taxa. • KEY RESULTS The majority of the crosses formed no viable seed. Although seed did mature in several of the crosses, morphological screening of the resulting seedlings indicated that they were the result of self-pollination. • CONCLUSIONS This result suggests that B. alba and B. pilosa are incapable of hybridizing with these Hawaiian Bidens taxa. Further, we found that B. alba in Hawaii was self-compatible, despite self-incompatibility throughout its native range, and that the tetraploid species B. alba and the hexaploid species B. pilosa were cross-compatible, although pollen fertility was low.

Genetic Structure and Diversity of a Rare Hawaiian Endemic, Lobelia villosa (Campanulaceae: Lobelioideae)

Abstract: Microsatellite markers are valuable tools for determining amount and distribution of genetic diversity and differentiation within and between populations. In this study we examined the level of microsatellite variability within and among five populations of Lobelia villosa, a rare Hawaiian endemic lobeliad on the island of Kaua‘i. Populations of L. villosa were sampled from two regions on Kaua‘i: two populations at the Kilohana Lookout area and three populations from Alaka‘i Swamp. Nineteen microsatellite DNA primers were developed for L. villosa, 12 of which demonstrated polymorphism and were subsequently multiplexed and labeled for genotyping. An overall moderate degree of genetic differentiation was found within and between populations. Pairwise FST data showed population structure, and analysis with Structure software indicated two genetic clusters (K = 2) corresponding to the two sampled geographic regions. Although L. villosa exhibits moderate diversity, which exceeds that of other Hawaiian endemics with restricted distributions, measurements of FIS were positive across 10 out of 12 loci, suggesting that inbreeding is occurring at the population level.