Nejvíce citovaný článek - PubMed ID 28565514
BACKGROUND: Morphological divergence often increases with phylogenetic distance, thus making morphology taxonomically informative. However, transitions to asexual reproduction may complicate this relationship because asexual lineages capture and freeze parts of the phenotypic variation of the sexual populations from which they derive. Parasitoid wasps belonging to the genus Lysiphlebus Foerster (Hymenoptera: Braconidae: Aphidiinae) are composed of over 20 species that exploit over a hundred species of aphid hosts, including many important agricultural pests. Within Lysiphlebus, two genetically and morphologically well-defined species groups are recognised: the "fabarum" and the "testaceipes" groups. Yet within each group, sexual as well as asexual lineages occur, and in L. fabarum different morphs of unknown origin and status have been recognised. In this study, we selected a broad sample of specimens from the genus Lysiphlebus to explore the relationship between genetic divergence, reproductive mode and morphological variation in wing size and shape (quantified by geometric morphometrics). RESULTS: The analyses of mitochondrial and nuclear gene sequences revealed a clear separation between the "testaceipes" and "fabarum" groups of Lysiphlebus, as well as three well-defined phylogenetic lineages within the "fabarum" species group and two lineages within the "testaceipes" group. Divergence in wing shape was concordant with the deep split between the "testaceipes" and "fabarum" species groups, but within groups no clear association between genetic divergence and wing shape variation was observed. On the other hand, we found significant and consistent differences in the shape of the wing between sexual and asexual lineages, even when they were closely related. CONCLUSIONS: Mapping wing shape data onto an independently derived molecular phylogeny of Lysiphlebus revealed an association between genetic and morphological divergence only for the deepest phylogenetic split. In more recently diverged taxa, much of the variation in wing shape was explained by differences between sexual and asexual lineages, suggesting a mechanistic link between wing shape and reproductive mode in these parasitoid wasps.
This study provides evidence on integrating the morphological, field, and laboratory data, and application of the cytochrome oxidase subunit I (COI) barcoding gene to the three asexual or sexual Lysiphlebus spp., i.e., Lysiphlebus cardui (Marshall), Lysiphlebus confusus Tremblay and Eady and Lysiphlebus fabarum (Marshall) (Hymenoptera: Braconidae: Aphidiinae). New aphid- invasive plant association, Aphis fabae Scopoli (Hemipreta: Aphididae) on Impatiens glandulifera Royle, has been used in the same model area in the Czech Republic under the same sampling and rearing method for several consecutive years and throughout the season. For molecular identification of these three species, we used DNA sequences of the barcoding region of the mitochondrial COI gene. Although our results confirmed ecological and morphological differences among L. cardui, L. confusus, and L. fabarum, genetic analysis on the basis of COI mitochondrial barcoding gene does not support species status of the mentioned Lysiphlebus taxa. The level of morphological differentiation in these Lysiphlebus Förster species is in accordance with the usual species variability within subfamily Aphidiinae. However, it should be examined how appearance of asexual lineages affects the morphological or genetical variability.
- Klíčová slova
- Aphis fabae, Europe, Impatiens glandulifera, Lysiphlebus, taxonomy,
- MeSH
- ekosystém MeSH
- hostitelská specificita * MeSH
- mšice parazitologie MeSH
- sršňovití anatomie a histologie genetika MeSH
- taxonomické DNA čárové kódování MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
