Dismantling the intercontinental pathway of invasion of Bemisia tabaci cryptic invasive species using the nextRAD genome-wide scans approach

The sweetpotato whitefly Bemisia tabaci harbors a wide range of cryptic species that have been placed in phylogenetically distinct clades based on the COI mitochondrial DNA (mtCOI) gene region.  Four cryptic species are currently within the invasive clade; which are MEAM1 (global invader), MEAM2, MED (global invader) and Indian Ocean. Here, genomic DNA was extracted from individual whitefly specimens collected from various geographical localities and belonging to the four cryptic species, to conduct a genome-wide analysis using the nextera-tagmented reductively amplified DNA (nextRAD) approach, which is a PCR-based protocol that mimics RAD-sequencing without using restriction enzymes. Over 3,000 SNPs distributed throughout the genome were successfully obtained from single whitefly individuals.  These markers were used to infer the complex demographic history of Bemisia invasive species and deconstruct the plausible scenarios for gene flow and invasion pathway across continents. This study goes beyond the common aspects of the Bemisia tabaci species boundaries resolution to delve into the demographic history and possible migration events on a more global scale.