A phylogeographical analysis of the Bemisia tabaci species complex based on mitochondrial DNA markers

Abstract

Mitochondrial 16S ( approximately 550 bp) and cytochrome oxidase I (COI) ( approximately 700 bp) sequences were utilized as markers to reconstruct a phylogeography for representative populations or biotypes of Bemisia tabaci. 16S sequences exhibited less divergence than COI sequences. Of the 429 characters examined for COI sequences, 185 sites were invariant, 244 were variable and 108 were informative. COI sequence identities yielded distances ranging from less than 1% to greater than 17%. Whitefly 16S sequences of 456 characters were analysed which consisted of 298 invariant sites, 158 variable sites and 53 informative sites. Phylogenetic analyses conducted by maximum parsimony, maximum-likelihood and neighbour-joining methods yielded almost identical phylogenetic reconstructions of trees that separated whiteflies based on geographical origin. The 16S and COI sequence data indicate that the B-biotype originated in the Old World (Europe, Asia and Africa) and is most closely related to B-like variants from Israel and Yemen, with the next closest relative being a biotype from Sudan. These data confirm the biochemical, genetic and behavioural polymorphisms described previously for B. tabaci. The consideration of all global variants of B. tabaci as a highly cryptic group of sibling species is argued.

Partitioning of herbivore hosts across time and food plants promotes diversification in the Megastigmus dorsalis oak gall parasitoid complex

“…Tajima's D for M. dorsalis sp.2 shows no significant deviation from zero (Tajima's D  = −0.22, p  =   .48), and no signature of population growth. Host‐associated differentiation in M. dorsalis sp.2 parallels that seen in other insects (e.g., Frohlich, Torres‐Jerez, Bedford, Markham, & Brown, 1999; Lozier et al., 2007; Popkin et al., 2017) and is more pronounced than the HAD seen in the classic example of Rhagoletis fruit flies and their parasitoids (which is apparent in nuclear allele frequencies, but not in mitochondrial haplotypes; Powell et al., 2013, 2014; Hood et al., 2015). The rarity of gene flow between the two host races (identified in only seven of 112 individuals in our analyses) suggests that M. dorsalis sp.2 host races may be in the process of splitting into two daughter species, each specific to a single host oak section.…”

Microsatellites reveal extensive geographical, ecological and genetic contacts between invasive and indigenous whitefly biotypes in an insular environment

“…Laboratory controls were two Ms and three B insects from our laboratory strains. The mitochondrial cytochrome oxidase I (COI) gene, known as diagnostic for biotypes, was amplified and sequenced for 35 of the 662 wild individuals typed for microsatellites, using primers C1-J2195 and L2-N3014 (Frohlich et al, 1999). A neighbour-joining tree of the sequences (370 nucleotides) was constructed from the maximum likelihood distance matrix using DNAMAN (Saitou & Nei, 1987).…”

“…However, it has been well known since the 1950s that this species covers several distinct entities named ' biotypes' (Bird & Maramorosch, 1978). Biotypes cannot be distinguished morphologically, but they may exhibit measurably different life-history traits, host ranges, levels of insecticide resistance and abilities to carry plant viruses Horowitz et al, 2005 ;Byrne et al, 2003), and correspond to different mitochondrial DNA (mtDNA) clades (Frohlich et al, 1999). More than 20 biotypes have been described (Perring et al, 2001), most of which are specific to one region ; however, recent invasions have brought some pairs into sympatry.…”

Identification of mungbean lines with tolerance or resistance to yellow mosaic in fields in India where different begomovirus species and different Bemisia tabaci cryptic species predominate

“…Further steps were performed following the manufacturers´instructions but using half of the recommended volume of each solution. Part of the mitochondrial cytochrome oxidase I (mtCOI) gene was amplified by polymerase chain reaction (PCR) using the universal primers C1-J-2195 and L2-N-3014 (Frohlich et al 1999) and 2 μl template DNA in 25 μl reaction volume. PCR products were analyzed on agarose gels and at least one PCR amplicon per sampling location was sequenced (Sequiserve, Vaterstetten, Germany).…”