Being ghosted: determining the progenitor genomes and biogeographic origin of the invasive fern giant salvinia

• Published in: Biological invasions Vol. 27; no. 5; p. 121
• Main Authors: Sigel, Erin M., Mendez-Reneau, Jonas I., Sutherland, Brittany L., Schwartsburd, Pedro Bond, Holt, Stacy D., Beck, James B.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.05.2025; Springer Nature B.V
• Subjects: Aquatic ecology; Aquatic habitats; Biogeography; Biomedical and Life Sciences; Developmental Biology; DNA; Ecology; Eurasia; Ferns; ferns and fern allies; Floating plants; Freshwater & Marine Ecology; Gene sequencing; Genetic diversity; genetic variation; genome; geographical distribution; hybrids; Life Sciences; Nucleotide sequence; Original Paper; Phylogenetics; phylogeny; Plant Sciences; Polyploidy; Salvinia molesta; Sexual reproduction; South America; species; Zimbabwe; South America; Eurasia; Zimbabwe; Allopolyploid; Target-capture; Multiple origins; Ghost progenitors
• ISSN: 1387-3547; 1573-1464
• DOI: 10.1007/s10530-025-03580-x

Giant salvinia ( Salvinia molesta , Salviniaceae) is an invasive fern species infesting aquatic habitats in over 30 countries. It is a polyploid and thought to be of hybrid origin. While a variety of evidence suggests that this hybrid origin occurred in South America, its initial discovery in Zimbabwe sets up the alternative scenario of an origin in Africa or even Eurasia. DNA sequences from over 400 nuclear genes were obtained from a set of native and invasive S. molesta samples, as well as from specimens representing all extant Salvinia species. Phylogenetic analyses of these data suggest giant salvinia originated in South America from two ‘ghost’ progenitor taxa that are extinct or extant but highly cryptic and unknown to science. These analyses also indicate that considerable genetic diversity exists within S. molesta , a surprising finding given this species’ reported lack of sexual reproduction. Alternative hypotheses for the source of this diversity and the management implications for each scenario are discussed.