Search results for "Orphism."

Gentics of hilanenus colour polymorphism: the 28 genotypes.

2009

Sexual antagonism for testosterone maintains multiple mating behaviour

2011

Summary 1. The persistence of multiple mating remains one of the fundamental questions in evolutionary biology. In theory, multiple mating is predicted to improve female fitness cumulatively through direct and ⁄ or genetic benefits. However, intra-locus sexual conflicts may potentially constrain or even eliminate these benefits owing to the gender load imposed by sexually antagonistic selection. 2. Here, we tested whether sexually antagonistic selection can maintain the variance in multiple mating behaviour of bank voles (Myodes glareolus) by manipulating the hormone testosterone through artificial selection in the laboratory. Among mammals, testosterone is a sexually dimorphic fitness-rela…

Multilocus typing for characterization of ‘Candidatus Phytoplasma asteris’-related strains in several ornamental species in Italy

2018

Different ornamental plants showing symptoms referable to phytoplasma presence and collected between 1993 and 2015 in various floricultural areas in north and south of Italy, enclosing Sicily, resulted to be infected by ‘Candidatus Phytoplasma asteris’-related strains, and after PCR/RFLP identification on 16Sr gene were assigned to 16SrI-B subgroup. These infected samples were employed for phytoplasma strain differentiation on tuf, groel, rp and amp genes. In particular, the 23 phytoplasma strains employed were from hydrangea (5), primula (3), gentian (2), petunia (2) and gerbera (1) samples showing flower virescence; from gladiolus samples both in vivo and in micropropagation (2) showing t…

Disentangling phylogeography, polyploid evolution and taxonomy of a woodland herb (Veronica chamaedrys group, Plantaginaceae s.l.) in southeastern Eu…

2010

Southeastern Europe is a centre of European biodiversity, but very little is known about factors causing the observed richness. Here, we contribute to fill this gap by reconstructing the spatio-temporal diversification of the cytologically variable and taxonomically intricate complex of Veronica chamaedrys (Plantaginaceae s.l.), growing in open forests, forest edges and grasslands, with flow cytometry, molecular markers (AFLPs, plastid DNA sequences) and morphometry. Our results show that both diploid and tetraploid cytotypes are widespread, but diploids predominate on the southern Balkan Peninsula. Plastid sequences suggest a first split into three main lineages in the mid-Pleistocene and …

Genomic variation in tomato, from wild ancestors to contemporary breeding accessions

2015

[EN] Background: Domestication modifies the genomic variation of species. Quantifying this variation provides insights into the domestication process, facilitates the management of resources used by breeders and germplasm centers, and enables the design of experiments to associate traits with genes. We described and analyzed the genetic diversity of 1,008 tomato accessions including Solanum lycopersicum var. lycopersicum (SLL), S. lycopersicum var. cerasiforme (SLC), and S. pimpinellifolium (SP) that were genotyped using 7,720 SNPs. Additionally, we explored the allelic frequency of six loci affecting fruit weight and shape to infer patterns of selection. Results: Our results revealed a pat…

Dimorphism in inflorescence scent of dioecious wild grapevine

2016

Abstract Wild grapevine ( Vitis vinifera subsp. sylvestris ) is the dioecious ancestral form of grapevine, from which the domesticated cultivars have derived ( V. vinifera subsp. vinifera ). Little is known about the floral scent compounds of wild grapevine that is considered as being partly insect pollinated. The knowledge of volatiles released by male and female inflorescence may contribute to the understanding of the pollination biology of this endangered taxon. Inflorescence scents of male and female individuals were collected by dynamic headspace and analysed by thermal desorption-GC/MS. A total of 17 compounds of C5-branched chain alcohols, aliphatics, aromatics, and terpenoids were i…

Introduction of Mysis relicta (Mysida) reduces niche segregation between deep-water Arctic charr morphs

2019

This is a post-peer-review, pre-copyedit version of an article published in Hydrobiologia. The final authenticated version is available online at https://doi.org/10.1007/s10750-019-3953-4. Niche diversification of polymorphic Arctic charr can be altered by multiple anthropogenic stressors. The opossum-shrimp (Mysis relicta) was introduced to compensate for reduced food resources for fish following hydropower operations in Lake Limingen, central Norway. Based on habitat use, stomach contents, stable isotopes (δ13C, δ15N) and trophically transmitted parasites, the zooplanktivorous upper water-column dwelling ‘normal’ morph was clearly trophically separated from two sympatric deep-water morphs…

Light availability affects sex lability in a gynodioecious plant.

2016

PREMISE OF THE STUDY: Sex lability (i.e., gender diphasy) in plants is classically linked to the larger resource needs associated with the female sexual function (i.e., seed production) compared to the male function (i.e., pollen production). Sex lability in response to the environment is extensively documented in dioecious species, but has been largely overlooked in gynodioecious plants. METHODS: Here, we tested whether environmental conditions induce sex lability in the gynodioecious Geranium sylvaticum. We conducted a transplantation experiment in the field where plants with different sex expression were reciprocally transplanted between high light and low light habitats. We measured pla…

Transfer of individuals as a means of investigating natural selection in operation.

2009

Populations of Philaenus spumarius (Homoptera) displaying colour polymorphism at stable equilibrium were subjected to the introduction of alien phenotypes. In an exchange experiment between populations of isolated islands, 2/3 of population A, from Allgrundet, was transferred to Porskobben, and 2/3 of population P from Porskobben to Allgrundet. The immediate result of the transfer was A-type allele frequencies on Porskobben and P-type frequencies on Allgrundet. After four generations, the pre-transfer frequencies were almost completely restored. This change implies strong island-specific selection pressures. The process was remarkably rapid in view of the mixed composition of the gene pools…

Advantage of rare infanticide strategies in an invasion experiment of behavioural polymorphism

2012

Killing conspecific infants (infanticide) is among the most puzzling phenomena in nature. Stable polymorphism in such behaviour could be maintained by negative frequency-dependent selection (benefit of rare types). However, it is currently unknown whether there is genetic polymorphism in infanticidal behaviour or whether infanticide may have any fitness advantages when rare. Here we show genetic polymorphism in non-parental infanticide. Our novel invasion experiment confirms negative frequency-dependent selection in wild bank vole populations, where resource benefits allow an infanticidal strategy to invade a population of non-infanticidal individuals. The results show that infanticidal beh…