The use of molecular markers to study patterns of genotypic diversity in some invasive alien Fallopia spp. (Polygonaceae)

Abstract

Random amplified polymorphic DNA (RAPDs) and inter‐simple sequence repeats (inter‐SSRs) have been used to study clonal growth and hybridization in some non‐native, gynodioecious, invasive weeds from the genus Fallopia (Polygonaceae). At the study site (the River Kelvin, Glasgow, UK) a single genotype of Japanese knotweed (Fallopia japonica) was detected, consistent with all the individuals sampled being ramets of a single clone. Two genotypes of giant knotweed (F. sachalinensis) were detected, with one genotype accounting for all but one of the samples, again indicative of widespread clonal growth. Five genotypes of the hybrid between Japanese and giant knotweed (F.×bohemica) were recovered. F.×bohemica is the only male‐fertile taxon present at the site and it seems probable that at least some of this genetic variation is attributable to hybrid fertility. A single plant identified using morphological methods as a backcross between F. japonica and F.×bohemica was analysed, and the molecular data were consistent with this theory. A comparison of RAPDs and inter‐SSRs showed that the two techniques gave data that are broadly congruent, and both techniques showed a similar sensitivity in the number of genotypes detected.

Population genetic structure of a colonising, triploid weed, Hieracium lepidulum

“…We chose to use ISSRs (Zietkiewicz et al, 1994) because they have already been shown to generate sufficient markers to easily identify genotypic diversity in clonal plants (Hollingsworth et al, 1998;Chapman et al, 2000). The incorporation of strategies to minimise the effects of dominance (for a review, see Sales et al, 2001) allow the estimation of F ST values from dominant markers that are concordant with codominant allozyme markers (Aagaard et al, 1998;Jenczewski et al, 1999).…”

A simulation model of rhizome networks for Fallopia japonica (Japanese knotweed) in the United Kingdom

“…There is a large amount of additional literature on F. japonica covering areas including the ecology of the plant (Beerling et al, 1994;Child and Wade, 2000), its reproductive strategies and capabilities (Brock and Wade, 1992;Beerling et al, 1994;Brock et al, 1995;Hollingsworth and Bailey, 2000;de Waal, 2001;Price et al, 2002;Forman and Kesseli, 2003), management techniques and their effectiveness (Child and de Waal, 1997;Seiger and Merchant, 1997;Child et al, 1998;Dawson and Holland, 1999;Brabec and Pysek, 2000;Hathaway, 2000;Child et al, 2001;Green, 2003), the importance of scale in the interpretation of distribution maps and model output (Collingham et al, 2000;Hulme, 2003;Thuiller et al, 2003), its effects on riparian habitats (Pysek and Prach, 1993;Dawson and Holland, 1999;Tickner et al, 2001) and its genetic makeup and hybridisation (Beerling et al, 1994;Hollingsworth et al, 1998;Kim and Park, 2000). There is also a growing amount of data on the distribution of the plant throughout the British Isles collected for or by groups such as the City and Council of Swansea, the Cornwall Knotweed Forum and the Environment Agency.…”

Geographic origin and taxonomic status of the invasive Privet, Ligustrum robustum (Oleaceae), in the Mascarene Islands, determined by chloroplast DNA and RAPDs

“…These floras are, however, subject to serious threats from invading alien species. Introduced plant species now occur in virtually every inhabited part of the world, and a small minority of such plants can become aggressively invasive and displace native species from their habitats (Williamson, 1996;Hollingsworth et al, 1998;Milne and Abbott, 2000;Mooney and Cleland, 2001). The isolated biotas of oceanic tropical islands are particularly vulnerable to invasion by alien species, because they tend to comprise highly adapted specialist rather than generalist species.…”

“…Hybrids involving an invasive alien species such as L. robustum might result in the transfer of adaptive traits to the invader through introgression (Rieseberg and Wendel, 1993;Strefeler et al, 1996;Milne and Abbott, 2000), or produce a hybrid lineage more invasive than either parent (Daehler and Strong, 1997;Vila and D'Antonio, 1998;Ellstrand and Schierenbeck, 2000), or that has the potential to be so (Hollingsworth et al, 1998). Two other Ligustrum species, L. sinense and L. ovalifolium, occur as naturalised aliens in La Réunion.…”

“…Increased genetic diversity in introduced material relative to native material might indicate introgression, whereas direct evidence of this would be provided by the presence of several markers specific to one of the other naturalised species in accessions of L. robustum. RAPDs have previously been employed to demonstrate that introgressive hybridisation has (Daehler and Strong, 1997;Perron and Bousquet, 1997;Hollingsworth et al, 1998) or has not (Miller and Spooner, 1996;Kuehn et al, 1999) occurred between plant species. Moreover, RAPD markers have contributed to the taxonomic understanding of the widespread tropical weed Lantana camara (Scott et al, 1997) and have in some cases been used to indicate the appropriate taxonomic level at which taxa should be recognised (eg Spooner et al, 1997;Paterson and Snyder, 1999).…”