Nuclear and cytoplasmic differentiation among Mediterranean populations of Bemisia tabaci: testing the biological relevance of cytotypes

Abstract

Q1 and Q2 hybridise, which confirms that they belong to the same species, in spite of the high degree of genetic differentiation at both the cytoplasmic and nuclear levels, and also suggests that their symbiotic bacteria do not prevent hybridisation.

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

“…Later samples showed that Q2 was present in 2007 in the South of France, and also in Spain, where no data on previous years are apparently available. Taken together, these findings, as well as recent studies conducted in the South of France and Italy, also suggest that Q2 is spreading in the west Mediterranean.…”

“…The present results indicate reproductive compatibility between Q1 and Q2 MTs, which has been observed under laboratory conditions, even from distant geographic sites. Firstly, members of Q1 and Q2 populations were often undistinguishable by their microsatellite‐based profiles (Fig.…”

Further insight into reproductive incompatibility between putative cryptic species of the Bemisia tabaci whitefly complex

“…FJ766390), Q2 and ASL of the MED whitefly are 1.07%, 1.98% and 1.67%, respectively. While the Q1 and Q2 “cytotypes” were reported to have frequent gene flow between them, little or no gene flow seemed to be detected between the Q1 and ALS cytotypes even though the latter two cytotypes occurred frequently in sympatry in nature, indicating that Q1 and ASL cytotypes are probably two cryptic species within the MED genetic group (Gauthier et al ., ; Terraz et al ., ; Mouton et al ., ).…”

Invasion of the Q2 mitochondrial variant of Mediterranean Bemisia tabaci in southern Italy: possible role of bacterial endosymbionts

“…Fertile hybrids were produced in laboratory reciprocal crosses between two strains of MED from Spain (probably Q1) and Israel (probably Q2) . Recently, complete reproductive compatibility in laboratory crossing experiments between Q1 and Q2 populations was recorded . Furthermore, based on microsatellite analysis of field populations, it was shown that hybridisation between Q1 and Q2 populations occurs in nature, but the gene flow was asymmetric and characterised by the introgression of the Q1 nuclear genetic background into the Q2 cytoplasmic background (mitochondria and endosymbiont genes) .…”

“…83 Recently, complete reproductive compatibility in laboratory crossing experiments between Q1 and Q2 populations was recorded. 84 Furthermore, based on microsatellite analysis of field populations, it was shown that hybridisation between Q1 and Q2 populations occurs in nature, but the gene flow was asymmetric and characterised by the introgression of the Q1 nuclear genetic background into the Q2 cytoplasmic background (mitochondria and endosymbiont genes). 72 In the same work, some Q2 populations turned out to be infected at high prevalence by Wolbachia, suggesting cytoplasmic incompatibility as a possible mechanism causing the asymmetric gene flow between differently Wolbachia-infected Q1 and Q2 populations.…”