scholarly journals Untargeted Metabolomics Approach Reveals Differences in Host Plant Chemistry Before and After Infestation With Different Pea Aphid Host Races

2019 ◽  
Vol 10 ◽  
Author(s):  
Carlos Sanchez-Arcos ◽  
Marco Kai ◽  
Aleš Svatoš ◽  
Jonathan Gershenzon ◽  
Grit Kunert
2018 ◽  
Vol 14 (11) ◽  
pp. 20180332 ◽  
Author(s):  
Varvara Fazalova ◽  
Bruno Nevado ◽  
Ailsa McLean ◽  
H. Charles J. Godfray

Human activities may weaken or destroy reproductive isolation between young taxa, leading to their fusion with consequences for population and community ecology. Pea aphid host races are adapted to different legume taxa, providing a degree of pre-mating isolation mediated by habitat choice. Yet, all races can feed and reproduce on the broad bean ( Vicia faba ), a major crop which represents a ‘universal host plant’, which can promote hybridization between races. Here, we ask if pea aphid host races have reproductive barriers which prevent or reduce gene flow when they co-occur on the universal host plant. We observed mating behaviour, female survival, number of eggs and egg fertilization rates for three types of crosses: among individuals of the same host race, between closely related host races and between distantly related host races. We did not find significant differences in mating behaviour and female survival among the three types of crosses. However, we observed a drastic reduction in the number of eggs laid, and in the number of fertilized eggs, in distant crosses. We conclude that widespread broad bean cultivation in agriculture may predispose closely related—but not distantly related—host races to hybridize, disrupting reproductive isolation between incipient species.


2020 ◽  
Vol 37 (7) ◽  
pp. 2045-2051
Author(s):  
Varvara Fazalova ◽  
Bruno Nevado

Abstract Accurate estimates of divergence times are essential to understand the evolutionary history of species. It allows linking evolutionary histories of the diverging lineages with past geological, climatic, and other changes in environment and shed light on the processes involved in speciation. The pea aphid radiation includes multiple host races adapted to different legume host plants. It is thought that diversification in this system occurred very recently, over the past 8,000–16,000 years. This young age estimate was used to link diversification in pea aphids to the onset of human agriculture, and led to the establishment of the pea aphid radiation as a model system in the study of speciation with gene flow. Here, we re-examine the age of the pea aphid radiation, by combining a mutation accumulation experiment with a genome-wide estimate of divergence between distantly related pea aphid host races. We estimate the spontaneous mutation rate for pea aphids as 2.7×10-10 per haploid genome per parthenogenic generation. Using this estimate of mutation rate and the genome-wide genetic differentiation observed between pea aphid host races, we show that the pea aphid radiation is much more ancient than assumed previously, predating Neolithic agriculture by several hundreds of thousands of years. Our results rule out human agriculture as the driver of diversification of the pea aphid radiation, and call for re-assessment of the role of allopatric isolation during Pleistocene climatic oscillations in divergence of the pea aphid complex.


2019 ◽  
Author(s):  
Varvara Fazalova ◽  
Bruno Nevado

AbstractAccurate estimates of divergence times are essential to understand the evolutionary history of species. It allows linking evolutionary histories of the diverging lineages with past geological, climatic and other changes in environment and shed light on the processes involved in speciation. The pea aphid radiation includes multiple host races adapted to different legume host plants. It is thought that diversification in this system occurred very recently, over the past 8,000 to 16,000 years. This young age estimate was used to link diversification in pea aphids to the onset of human agriculture, and lead to the establishment of the pea aphid radiation as a model system in the study of speciation with gene flow. Here, we re-examine the age of the pea aphid radiation, by combining a mutation accumulation experiment with a genome-wide estimate of divergence between distantly related pea aphid host races. We estimate the spontaneous mutation rate for pea aphids as 2.27 × 10−10 per haploid genome per parthenogenic generation. Using this estimate of mutation rate and the genome-wide genetic differentiation observed between pea aphid host races, we show that the pea aphid radiation is much more ancient than assumed previously, predating Neolithic agriculture by several hundreds of thousands of years. Our results rule out human agriculture as the driver of diversification of the pea aphid radiation, and call for re-assessment of the role of allopatric isolation during Pleistocene climatic oscillations in divergence of the pea aphid complex.


Genome ◽  
1998 ◽  
Vol 41 (6) ◽  
pp. 769-775 ◽  
Author(s):  
Elizabeth Grace Boulding

Pea aphid (Acyrthosiphon pisum) clones have been shown to be adapted to particular host plant species but it is unknown whether there are host races. A 1101 base pair region of the mitochondrial cytochrome oxidase I gene (COI) was sequenced for 21 pea aphid clones that had been collected from different host plants in Canada and the U.S.A. Only five closely related mitochondrial haplotypes were found. A maximum likelihood phylogeny was estimated for these five haplotypes and four related aphid species: Acyrthosiphon macrosiphum, A. kondoi, Fimbriaphis fimbriata, and Macrosiphum creelii. Pea aphids from the same host plant species were no more likely to have the same mitochondrial haplotype than aphids from different host plant species. In addition, aphids from the same geographical regions were no more likely to have the same mitochondrial haplotype than aphids from different geographic regions. I therefore reject the hypothesis that there are monophyletic host races of the pea aphid.Key words: cytochrome oxidase I, exotic species, host plant, mtDNA sequence, phylogeny.


2018 ◽  
Vol 27 (16) ◽  
pp. 3287-3300 ◽  
Author(s):  
Pierre Nouhaud ◽  
Mathieu Gautier ◽  
Anaïs Gouin ◽  
Julie Jaquiéry ◽  
Jean Peccoud ◽  
...  

2006 ◽  
Vol 7 (1) ◽  
pp. 34 ◽  
Author(s):  
Stephen L. Clement

This review documents the history of pea aphid outbreaks and epidemics of pea aphid-transmitted viruses on peas in the Pacific Northwest, with emphasis on outbreaks and epidemics in the Palouse region of eastern Washington over 23 years. This article will enable researchers and industry leaders to target resources to areas requiring more research for better understanding of pea aphid-host plant-virus relationships in the Pacific Northwest. Accepted for publication 3 August 2006. Published 18 October 2006.


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