Genetic structure of Bemisia tabaci Med populations from home‐range countries, inferred by nuclear and cytoplasmic markers: impact on the distribution of the insecticide resistance genes

Abstract

Med B. tabaci is more diverse and structured than reported so far. On a large geographic scale, resistance is affected by population genetic structure, whereas on a local scale, agricultural practices appear to play a major role.

First report of the Sub-Saharan Africa 2 species of the Bemisia tabaci complex in the Southern France

“…In Southern France, more than 1000 B. tabaci from 22 samples, including the 13 samples already analysed in a previous study (Gauthier et al 2014), were collected between 2006 and 2009 on various cultivated vegetables (e.g., tomato, Solanum lycopersicum; aubergine, S. melongena; soybean, Glycine max) as well as ornamentals and weeds that have become very common components of natural and agricultural Mediterranean ecosystems (e.g., lantana, Lantana camara; hibiscus, Hibiscus sp. ; gerbera, Gerbera sp.…”

“…and for some individuals, by additional previously identified loci (Gauthier et al 2008;Hadjistylli 2010;Hadjistylli et al 2014). The COI fragment gene of at least one individual per sample was sequenced, particularly in the case of specimen(s) which showed no or no typical digestion patterns with restriction enzymes, or numerous null-alleles with the microsatellite loci distributed in multiplex sets for population genetics studies (Saleh et al 2012;Gauthier et al 2014). The specimens for which DNA was sequenced were assigned to B. tabaci species according to the match between their consensus COI sequences of 676-bp and homologous COI sequences from GenBank.…”

“…Experimental conditions for (1) mtDNA PCR amplification, enzymatic digestion (PCR-RFLP) and gel revelation, and sequencing, and (2) microsatellite polymerase chain reaction (PCR) amplification and genotyping are described in Gauthier et al (2014) and Hadjistylli et al (2014).…”

“…Since the B. tabaci complex consists of morphocryptic species, we used diagnostic and highly discriminatory molecular markers, including variation in nuclear microsatellites and mitochondrial cytochrome oxidase I (COI) through PCR-RFLP and DNA sequencing (Saleh et al 2012;Gauthier et al 2014;Laarif et al 2015). Here, we focus on the first report of the sub-Saharan Africa 2 (SSA2) species in Southern France and the possible implications of such a result in the context of invasion of the Mediterranean area by new B. tabaci species.…”

“…Med, MEAM1, MEAM2, SSA-2 (formerly referred to as biotype S), Italy (formerly referred to as biotype T) and Asia I (formerly referred to as biotype M)] of the complex have been reported (De la Rúa et al 2006;Sartor et al 2008;Bielza et al 2013;Karut et al 2015), but currently Med and MEAM1 species are the most prevalent. In recent years, MEAM1 was reported to have been displaced or even totally supplanted by Med (the western Mediterranean populations also called Q1 Med) B. tabaci species in many Mediterranean countries including Spain, Greece, France, Italy and Morocco (Simón et al 2007;Tsagkarakou et al 2007;Parrella et al 2012;Tahiri et al 2013;Gauthier et al 2014). Though not common, some Mediterranean regions still equally host both Med and MEAM1 (Laarif et al 2015), whereas in the eastern Mediterranean, for example in Cyprus, MEAM1 is dominant with Med (the middle-eastern Mediterranean populations also called Q2 Med) having a much more restricted distribution (Hadjistylli, unpublished data).…”