Microsatellite isolation, linkage group identification and determination of recombination frequency in the peach-potato aphid, Myzus persicae (Sulzer) (Hemiptera : Aphididae)

Fifteen polymorphic microsatellite markers were used to establish linkage g roups and relative rates of recombination in male and female Myzus persicae (Sulzer) (Hemiptera: Aphididae) (peach-potato aphid). We cloned nine marke rs from M. persicae and for these we report primer sequences and levels of allelic diversity and heterozygosity in four Australian M. persicae populat ions. Of the remaining six loci, four loci, also cloned from M. pcr sic nc, were obtained from G. Malarky (Natural History Museum, London) and two loc i from Sitobion miscanthi were used. Additionally, the primer sequences of locus M77, a locus monomorphic in M. persicae but polymorphic in the closel y related Myzus antirrhinii, are presented. Eleven of the 15 polymorphic ma rkers were autosomal and four were X-linked. A linkage analysis was perform ed on a European pedigree of aphids containing five families with between s even and ii offspring each. There was no linkage between any loci in female s. In males, several pairwise comparisons yielded no recombinant offspring. With the exception of locus M40, these observations were supported in a li nkage analysis performed on larger families produced from Australian M. per sicae crosses. Locus M40 showed segregation consistent with involvement in a translocation between autosomes 1 and 3 in European samples but not in th e Australian samples. From the Australian crosses we report an absence of r ecombination in males but high recombination rates in females. One X chromo some and four autosomal linkage groups were identified and tentatively assi gned to chromosomes. The relevance of achiasmate meiosis to the evolution o f sex is discussed.