scholarly journals Intrinsic pre-zygotic reproductive isolation of distantly related pea aphid host races

2018 ◽  
Vol 14 (11) ◽  
pp. 20180332 ◽  
Author(s):  
Varvara Fazalova ◽  
Bruno Nevado ◽  
Ailsa McLean ◽  
H. Charles J. Godfray
Keyword(s):  
Reproductive Isolation ◽  
Host Plant ◽  
Broad Bean ◽  
Mating Behaviour ◽  
Habitat Choice ◽  
Pea Aphid ◽  
Drastic Reduction ◽  
Host Races ◽  
Female Survival ◽  
Aphid Host

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.

scholarly journals Low Spontaneous Mutation Rate and Pleistocene Radiation of Pea Aphids

2020 ◽  
Vol 37 (7) ◽  
pp. 2045-2051
Author(s):  
Varvara Fazalova ◽  
Bruno Nevado
Keyword(s):  
Mutation Rate ◽  
Spontaneous Mutation ◽  
Pea Aphid ◽  
Spontaneous Mutation Rate ◽  
Host Races ◽  
Climatic Oscillations ◽  
Genome Wide ◽  
A Genome ◽  
Pea Aphids ◽  
Aphid Host

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.

scholarly journals Low spontaneous mutation rate and Pleistocene radiation of pea aphids

2019 ◽  
Author(s):  
Varvara Fazalova ◽  
Bruno Nevado
Keyword(s):  
Mutation Rate ◽  
Spontaneous Mutation ◽  
Pea Aphid ◽  
Spontaneous Mutation Rate ◽  
Host Races ◽  
Climatic Oscillations ◽  
Genome Wide ◽  
A Genome ◽  
Pea Aphids ◽  
Aphid Host

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.

Molecular evidence against phylogenetically distinct host races of the pea aphid (Acyrthosiphon pisum)

Genome ◽  
1998 ◽  
Vol 41 (6) ◽  
pp. 769-775 ◽  
Author(s):  
Elizabeth Grace Boulding
Keyword(s):  
Host Plant ◽  
Cytochrome Oxidase ◽  
Plant Species ◽  
Acyrthosiphon Pisum ◽  
Cytochrome Oxidase I ◽  
Pea Aphid ◽  
Mitochondrial Haplotype ◽  
Host Races ◽  
Host Plant Species ◽  
Geographical Regions

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.

Identifying genomic hotspots of differentiation and candidate genes involved in the adaptive divergence of pea aphid host races

2018 ◽  
Vol 27 (16) ◽  
pp. 3287-3300 ◽  
Author(s):  
Pierre Nouhaud ◽  
Mathieu Gautier ◽  
Anaïs Gouin ◽  
Julie Jaquiéry ◽  
Jean Peccoud ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Pea Aphid ◽  
Adaptive Divergence ◽  
Host Races ◽  
Aphid Host

Pea Aphid Outbreaks and Virus Epidemics on Peas in the US Pacific Northwest: Histories, Mysteries, and Challenges

2006 ◽  
Vol 7 (1) ◽  
pp. 34 ◽  
Author(s):  
Stephen L. Clement
Keyword(s):  
Host Plant ◽  
Pacific Northwest ◽  
Plant Virus ◽  
Pea Aphid ◽  
The Pacific ◽  
The Us ◽  
History Of ◽  
Eastern Washington ◽  
Aphid Host

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.

Effect of Host-plant on the Resistance of Acyrthosiphon pisum (Harris) to Insecticides

1957 ◽  
Vol 48 (2) ◽  
pp. 317-322 ◽  
Author(s):  
C. Potter ◽  
E. M. Gillham
Keyword(s):  
Body Weight ◽  
Host Plant ◽  
Dry Matter ◽  
Host Plants ◽  
Acyrthosiphon Pisum ◽  
Broad Bean ◽  
Pea Aphid ◽  
Equal Weight ◽  
Unit Body Weight ◽  
The Difference

SummaryBy means of a laboratory spraying technique, ten comparisons were made of the resistance to rotenone of samples of adult apterous viviparous parthenogenetic females of the Pea Aphid, Acyrthosiphon pisum (Harris), reared on broad bean and on clover, respectively. In nine of the tests, the Aphids from clover were more resistant than those from broad bean, the ratios ranging from 1·1 to 2·5. These differences were not all significant. In the remaining test the Aphids. from broan bean showed a very small increase in resistance over the Aphids from clover which was not significant.The Aphids from the clover were generally smaller than those from broad bean. Figures are given to show that while the total amount of poison retained by the larger individuals from broad bean was more than that retained by the smaller individuals from clover, the amount of poison retained per unit body weight was greater with the smaller individuals. It appears, therefore, that while the results obtained might be due, at least partially, to the greater total weight of poison retained by the larger individuals from broad bean, the difference in resistance between the insects from broad bean and clover, respectively, might be even greater if the poison were applied on the basis of equal weight of poison per unit of body weight. Since the difference in resistance between the Aphids from the two host-plants did not appear to depend primarily on difference in size, the assumption might be made that it is due to difference in nutrition. It was found that Aphids reared on clover had a significantly higher proportion of dry matter in their composition than those reared on broad bean, which may be taken as evidence that differences due to nutrition are being produced. These may lead to differences in resistance.

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