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 (F(ST) = 0.0) and is supported by extreme low quantitative trait variance (Q(ST) = 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.
Le Roux
Johannes J
JJ
Department of Tropical Plant and Soil Sciences, University of Hawaii at Manoa, Honolulu, Hawaii, United States of America. roux@hawaii.edu
Wieczorek
Ania M
AM
Wright
Mark G
MG
Tran
Carol T
CT
D017753:Ecosystem; D004777:Environment; D005819:Genetic Markers; D014644:Genetic Variation; D005838:Genotype; D006254:Hawaii; D018895:Microsatellite Repeats; D008957:Models, Genetic; D031782:Pennisetum / Q000145:classification / Q000235:genetics*; D010802:Phylogeny; D012641:Selection, Genetic; D013019:South Africa; D014158:Transcription, Genetic
D005819:Genetic Markers