Afit: a bioinformatic tool for measuring aphid fitness and invasiveness

Abstract

A careful measure of fitness represents a crucial target in crop pest management and becomes fundamental considering extremely prolific insects. In the present paper, we describe a standardized rearing protocol and a bioinformatics tool to calculate aphid fitness indices and invasiveness starting from life table data. We tested the protocol and the bioinformatic tool using six Myzus persicae (Sulzer) asexual lineages in order to investigate if karyotype rearrangements and ecotype could influence their reproductive performances. The tool showed that different karyotypes do not influence adaptive success and put in evidence a marked invasive potential of the M. persicae lineage 64. The presence of a similar fitness rate of 33H and 7GK asexual lineages (both possessing intra-individual karyotype variations) in respect to the asexual lineage 1 (with a standard karyotype) represents an important demonstration of the potentiality of holocentric chromosomes to reduce the effects of chromosome rearrangements.

The Evolutionary History and Functional Divergence of Trehalase (treh) Genes in Insects

“…The presence of co-evolution between plant trehalase inhibition and duplication/fixation of mutations in the treh genes could be particularly relevant in aphids in view of their peculiar reproductive mode. Indeed, the reproduction of aphids is mainly based (with the exception of a unique generation in autumn) on apomictic parthenogenesis consisting in several thelytokous parthenogenetic generations, in which unfertilized eggs develop into females (Nardelli et al, 2017). In the absence of an amphygonic reproduction, aphids cannot have any recombination between female and male genomes during spring and summer causing a reduced gene flow that will delay the spread of advantageous alleles.…”

The foraging Gene Is Involved in the Presence of Wings and Explorative Behaviours in Parthenogenetic Females of the Aphid Myzus persicae

“…The difficulty of these experiments is related to the presence of multiple unsynchronous individuals in insect populations. In laboratory conditions, as assessed by Nardelli et al [ 26 ], it is possible to collect synchronous M. persicae individuals and populations so that it is easier to compare qPCR replicates, avoiding the high range of standard errors observed in previous experiments in other aphid species [ 13 ].…”

Composition and biological activity of essential oils from Artemisia roxburghiana Besser and Elsholtzia fruticosa Rehder cultivated in Italy

“…A regime of 16 h of light and 8 h of dark was applied. The M. persicae strains #1 and #64 described by Nardelli et al (2017) were used in this study. M. persicae asexual lineage 1 was originally collected on peach Prunus persica, whereas lineage was sampled from Nicotiana tabacum.…”