Search results for "ail"

A genomic map of climate adaptation in Mediterranean cattle breeds

2019

International audience; Domestic species such as cattle (Bos taurus taurus and B. t. indicus) represent attractive biological models to characterize the genetic basis of short term evolutionary response to climate pressure induced by their post-domestication history. Here, using newly generated dense SNP genotyping data, we assessed the structuring of genetic diversity of 21 autochtonous cattle breeds from the whole Mediterranean basin and performed genome-wide association analyses with covariables discriminating the different Mediterranean climate sub-types. This provided insights into both the demographic and adaptive histories of Mediterranean cattle. In particular, a detailed functional…

Current Experience with Application of Metal-based Nanofertilizers

2019

Agriculture is one of the many fields in which nanotechnology is currently applied. At the nano-scale, materials exhibit different properties mainly due to the reduced molecular size which allows different interactions between molecules. Nowadays, the agricultural sector demands methods that not only increase crop productivity, but are also sustainable and produce less environmental impact. Large-scale application of chemical fertilizers is common in farming with the aim of increasing productivity. The use of large doses of fertilizers, however, causes more harm than good. Chemically intensive agriculture disturbs the soil-mineral balance, pollutes soil, water and air, and makes lands less …

Private information alone can trigger trapping of ant colonies in local feeding optima.

2015

Ant colonies are famous for using trail pheromones to make collective decisions. Trail pheromone systems are characterised by positive feedback, which results in rapid collective decision making. However, in an iconic experiment, ants were shown to become 'trapped' in exploiting a poor food source, if it was discovered earlier. This has conventionally been explained by the established pheromone trail becoming too strong for new trails to compete. However, many social insects have a well-developed memory, and private information often overrules conflicting social information. Thus, route memory could also explain this collective 'trapping' effect. Here, we disentangled the effects of social …

Love at first sniff: a spermatophore-associated pheromone mediates partner attraction in a collembolan species

2017

Mate choice is essential in most animals, as a good choice of mating partner largely determines reproductive success. Much evidence shows that olfactory cues play an important role in mate choice. However, the integration of chemical, visual and acoustic cues, often used when both partners meet, makes it hard to test whether olfaction alone can mediate reproductive decisions. Interestingly, several invertebrates have adopted a mating system where males deposit their sperm (packed in spermatophores) in the environment for females to pick up with no visual contact between the sexes. In this case the male cue is conveyed by the spermatophore only. Earlier studies on a species with indirect spe…

Postmating–prezygotic isolation between two allopatric populations of Drosophila montana: fertilisation success differs under sperm competition

2016

This study was funded by the Academy of Finland (grant 250999 to O. A.-H.). Postmating but prezygotic (PMPZ) interactions are increasingly recognized as a potentially important early-stage barrier in the evolution of reproductive isolation. A recent study described a potential example between populations of the same species: single matings between Drosophila montana populations resulted in differential fertilisation success because of the inability of sperm from one population (Vancouver) to penetrate the eggs of the other population (Colorado). As the natural mating system of D. montana is polyandrous (females remate rapidly), we set up double matings of all possible crosses between the sa…

Does silica concentration and phytolith ultrastructure relate to phytolith hardness?

2017

Abstract Grasses are an important part of the forage of many herbivorous mammals and their phytoliths have long been regarded as the most important agent of tooth wear. Recent work has challenged this “paradigm” in finding evidence 1. of native phytoliths to be much softer then tooth enamel and 2. indicating, that phytolith hardness is highly variable, 3. prone to methodology and 4. not easy to be related to habitat conditions. We conduct controlled silica-cultivations measuring SiO2 content in the common forage grass Themeda triandra. Phytoliths are extracted natively, and nano-indentation values are measured. Phytolith hardness in Themeda triandra is found to be independent of silicate av…

New Approaches to Optimize Somatic Embryogenesis in Maritime Pine

2019

Maritime pine (Pinus pinaster Aiton) is a coniferous native of the Mediterranean basin. Because of its adaptability to a wide range of environmental conditions, the species have become a model for studies in coniferous forest management and functional genomics. Somatic embryogenesis (SE) has been so far, the preferred biotechnological strategy for maritime pine breeding programs initiated at the middle-end of the 20th century. To overcome the limitations of the induction and maturation phases in maritime pine SE, we analyzed the possible maternal influence on the embryogenic capability of megagametophytes from controlled crosses, as well as the effect of the temperature and water availabili…

2013

Parasitized individuals are often expected to be poor competitors because they are weakened by infections. Many trematode species, however, although extensively exploiting their mollusc hosts, also induce gigantism (increased host size) by diverting host resources towards growth instead of reproduction. In such systems, alternatively to reduced competitive ability due to negative effects of parasitism on host performance, larger size could allow more efficient resource acquisition and thus increase the relative competitive ability of host individuals. We addressed this hypothesis by testing the effect of a trematode parasite Diplostomum pseudospathaceum on the competitive ability of its sna…

Why no tetraploid cultivar of foxtail millet?

2004

Autotetraploid material was induced by colchicine treatment of a pure line of foxtail millet and an interspecific hybrid between foxtail millet and giant green foxtail. Compared with diploid material, tetraploids were smaller, flowered later, and had a two-fold reduced fertility (number of grain per cm of spike). Grain weight increased by 20% with polyploidy, but total grain yield decreased by 46%. This work illustrates the difficulty of breeding polyploid lines of foxtail millet that are of agronomic use.

Direct and transgenerational effects of an experimental heat wave on early life stages in a freshwater snail

2018

AbstractGlobal climate change imposes a serious threat to natural populations of many species. Estimates of the effects of climate change-mediated environmental stresses are, however, often based only on their direct effects on organisms, and neglect the potential transgenerational effects. We investigated whether high temperature (i.e. an experimental heat wave) that is known to reduce performance of adultLymnaea stagnalissnails affects their offspring through maternal effects. Specifically, we tested whether eggs and hatched juveniles are affected by maternal thermal environment, and how strong these effects are compared with direct effects of temperature on offspring. We examined the eff…