Insight into the durability of plant resistance to aphids from a demo‐genetic study of Aphis gossypii in melon crops

Abstract

Resistance breakdown has been observed following the deployment of plant cultivars resistant to pests. Assessing the durability of a resistance requires long‐term experiments at least at a regional scale. We collected such data for melon resistance conferred by the Vat gene cluster to melon aphids. We examined landscape‐level populations of Aphis gossypii collected in 2004–2015, from melon‐producing regions with and without the deployment of Vat resistance and with different climates. We conducted demo‐genetic analyses of the aphid populations on Vat and non‐Vat plants during the cropping seasons. The Vat resistance decreased the density of aphid populations in all areas and changed the genetic structure and composition of these populations. Two bottlenecks were identified in the dynamics of adapted clones, due to the low levels of production of dispersal morphs and winter extinction. Our results suggest that (i) Vat resistance will not be durable in the Lesser Antilles, where no bottleneck affected the dynamics of adapted clones, (ii) Vat resistance will be durable in south‐west France, where both bottlenecks affected the dynamics of adapted clones and (iii) Vat resistance will be less durable in south‐east France, where only one of the two bottlenecks was observed.

Highly conserved genes expressed in aphid saliva are candidates for host plant adaptation in Aphis gossypii

“…gossypii nuclear genome, as shown by its alleles for the SSR markers and CDSs characterized here. GEL6 was collected from cucurbits and observed on melon crops at different sites in France [55]. It had the biological features of clones specializing on cucurbits.…”

Bacterial communities in natural versus pesticide‐treated Aphis gossypii populations in North China

“…The cotton‐melon aphid, Aphis gossypii Glover, is a species that is increasing worldwide, colonizing more than 600 plant species (Blackman & Eastop, ). It causes serious economic losses in agriculture by feeding on plant foliage and spreading viral diseases in plants, such as cotton, cucurbits, and citrus (Thomas, Vanlerberghe‐Masutti, Mistral, Loiseau, & Boissot, ). It has been described as holocyclic in North China: eggs hatch in March and after two to three generations, late adults appear and move to cotton fields during late April to mid‐May.…”

Genetic diversity of melon aphids Aphis gossypii associated with landscape features

“…Early season individuals on melon were alates, and so the entire potential colonizing population was sampled. Host plant pressure on aphids occurs in melons and aphid‐resistant melon cultivars and could alter the genetic structure of A. gossypii (Thomas et al., , ). In the present study, there was no known commercial aphid‐resistant melon varieties planted in the research area.…”

“…The effects of landscape features on aphid dispersal have been documented (Angelella, Holland, & Kaplan, 2016;Gilabert et al, 2017). Thomas, Vanlerberghe-Masutti, Mistral, Loiseau, and Boissot (2016) conducted demo-genetic analyses of aphid populations on aphid-resistant plants during growth seasons and found that plant resistance changed the genetic structure of the aphid populations. Factors that modify the dispersal of founders may also modify the genetic composition of the population.…”