Karyotype variations in Italian populations of the peach-potato aphid Myzus persicae (Hemiptera: Aphididae)

In this study, we present cytogenetic data regarding 66 Myzus persicae strains collected in different regions of Italy. Together with the most common 2n=12 karyotype, the results showed different chromosomal rearrangements: 2n=12 with A1-3 reciprocal translocation, 2n=13 with A1-3 reciprocal translocation and A3 fission, 2n=13 with A3 fission, 2n=13 with A4 fission, 2n=14 with X and A3 fissions. A 2n=12-13 chromosomal mosaicism has also been observed. Chromosomal aberrations (and in particular all strains showing A1-3 reciprocal translocation) are especially frequent in strains collected on tobacco plants, and we suggest that a clastogenic effect of nicotine, further benefited by the holocentric nature of aphid chromosomes, could be at the basis of the observed phenomenon.