title: Molecular characterization of Bemisia tabaci populations in Tunisia: genetic structure and evidence for multiple acquisition of secondary symbionts.
abstract: A survey was conducted during 2009-2010 seasons to identify the distribution of Bemisia tabaci (Gennadius) biotypes in Tunisia. The genetic affiliation of collected populations was determined by polymerase chain reaction (PCR)-restriction fragment-length polymorphism (TaqI)  of the mitochondrial cytochrom oxidase I (mtCOI) gene. Results, validated by sequencing and phylogenetic analysis, allowed the clustering of sampled sweetpotato whiteflies into B and Q biotypes. As B. tabaci harbors the obligatory bacterium Portiera aleyrodidarum, and a diverse array of secondary  symbionts including Rickettsia, Hamiltonella, Wolbachia, Cardinium, Arsenophonus, and Fritschea, we report here the infectious status of Tunisian populations by secondary symbionts to find out a correlation between bacterial composition to biotype. The genetic variability and structure  of B. tabaci populations in Tunisia was driven by analysis of molecular variance (AMOVA) and the hypothesis of isolation by distance was explored. Selective neutrality and genetic haplotype network tests suggested that Tunisian sweetpotato whiteflies have been undergoing a potential expansion  followed by gene flow restriction.
authors.affiliation: Laboratory of Molecular Genetics, Immunology and Biotechnology. Faculty of Sciences of Tunis, 2092 Elmanar Tunis, Tunisia. faten.gorsane@fss.rnu.tn
authors.forename: F
authors.initials: F
authors.lastname: Gorsane
authors.forename: A
authors.initials: A
authors.lastname: Ben Halima
authors.forename: M
authors.initials: M
authors.lastname: Ben Khalifa
authors.forename: M S
authors.initials: MS
authors.lastname: Bel-Kadhi
authors.forename: H
authors.initials: H
authors.lastname: Fakhfakh
mesh_terms: D000818:Animals; D003576:Electron Transport Complex IV / Q000235:genetics; D050259:Genes, Mitochondrial; D014644:Genetic Variation; D005843:Geography; D006430:Hemiptera / Q000235:genetics* / Q000382:microbiology; D017422:Sequence Analysis, DNA; D013559:Symbiosis; D014416:Tunisia
chemical_list: D003576:Electron Transport Complex IV