Search results for "POPULATION"
showing 10 items of 9945 documents
Genetic analysis of organoleptic quality in fresh market tomato. 1. Mapping QTLs for physical and chemical traits
2001
Improving organoleptic quality is an important but complex goal for fresh market tomato breeders. A total of 26 traits involved in organoleptic quality variation were evaluated, in order to understand the genetic control of this characteristic. A recombinant inbred line (RIL) population was developed from an intraspecific cross between a cherry tomato line with a good overall aroma intensity and an inbred line with a common taste but with bigger fruits. Physical traits included fruit weight, diameter, color (L,a,b), firmness and elasticity. Chemical traits were dry matter weight, titratable acidity, pH, and the contents of soluble solids, sugars, lycopene, carotene and 12 aroma volatiles. R…
Do peahens not prefer peacocks with more elaborate trains?
2008
Ever since Darwin (1871), the peacock’s train has been cited as the icon of an extravagant conspicuous secondary sexual trait that has evolved through female mate choice. However, Takahashi et al. (2008) recently challenged this idea. They monitored female mate choice during 7 years in a feral peafowl, Pavo cristatus, population in Japan and found no correlation between male mating success and three morphological train traits. They concluded that ‘combined with previous results, our findings indicate that the peacock’s train is not currently the universal target of female choice’ and proposed ‘that the peacock’s train is an obsolete signal for which female preference has already been lost o…
New national and regional bryophyte records, 44
2015
Syntrichia norvegica is a circumpolar arctic- montane species (Smith, 2004), rare at lower altitudes and in southern Europe (Frey et al., 2006). It is known from several south-eastern European countries (Sabovljevic et al., 2008) and now it is recorded for the first time in Croatia. Regarding its conservation status, S. norvegica is red listed in Great Britain (EN), Czech Republic (CR), Slovakia (VU), Bulgaria (NT), Hungary (DD), Romania (VU) and Estonia (VU) (Hodgetts, 2014). It was found in the northern Velebit Mountains, in an area with the most outstanding and extreme karst relief, with steep slopes, perpendicular rocks, screes and deep dolines. The locality is situated in the Pinus mug…
Genetic structure of a European forest species, the edible dormouse ( Glis glis ): a consequence of past anthropogenic forest fragmentation?
2019
International audience; The genetic structure of forest animal species may allow the spatial dynamics of the forests themselves to be tracked. Two scales of change are commonly discussed: changes in forest distribution during the Quaternary, due to glacial/interglacial cycles, and current fragmentation related to habitat destruction. However, anthropogenic changes in forest distribution may have started well before the Quaternary, causing fragmentation at an intermediate time scale that is seldom considered. To explore the relative role of these processes, the genetic structure of a forest species with narrow ecological preferences, the edible dormouse (Glis glis), was investigated in a set…
Acoustic signalling in a wolf spider: can signal characteristics predict male quality?
2000
While there has been considerable interest in female choice for male sexual signals, there have been few studies of the underlying information that different aspects of the signal calls convey. Such studies, however, are essential to understand the significance of signals as honest handicaps, arbitrary Fisherian traits and/or in species recognition. We studied the somewhat exceptional system of audible drumming in the wolf spider Hygrolycosa rubrofasciata. We estimated the repeatabilities of signal components, the levels of between-male variance, the symmetry of the signal, the correlations between different aspects of drumming and their correlations with body weight. While in other taxa th…
Is a change in juvenile hormone sensitivity involved in range expansion in an invasive beetle?
2015
Introduction: It has been suggested that rapid range expansion could proceed through evolution in the endocrinological machinery controlling life-history switches. Based on this we tested whether the Colorado potato beetle, Leptinotarsa decemlineata, which has rapidly expanded its range across latitudinal regions in Europe, and shows photoperiodic adaptation in overwintering initiation, has different sensitivities to juvenile hormone (JH) manipulation along a latitudinal gradient. Results: A factorial experiment where beetles were reared either under a long or short day photoperiod was performed. Hormone levels were manipulated by topical applications. An allatostatin mimic, H17, was used t…
Genetic structure of a greenhouse population of the spider mite Tetranychus urticae: spatio-temporal analysis with microsatellite markers.
2002
International audience; The genetic structure of a greenhouse population of the mite Tetranychus urticae was studied by the analysis of five microsatellite loci. Genetic variation was compared during a crop season between periods of population foundation and rapid population increase and was investigated in two consecutive years. The population displayed significant heterozygote deficiency at all the sampling periods. However, inbreeding tended to decrease with increasing density (FIS coefficient between 0.13 and 0.25). No significant genetic differentiation between samples was found either at a spatial scale within the greenhouse or at a temporal scale between two growing seasons (FST betw…
Characterization of eight microsatellite loci for the sea urchin Meoma ventricosa (Spatangoida, Brissidae) through Next Generation Sequencing.
2015
Eight microsatellite loci were characterized for Meoma ventricosa (Lamarck, 1816), a burrowing sea urchin that can be afflicted by a bacterial disease causing localized mass mortality. For the analyzed population (29 individuals from St. Croix, US Virgin Islands), we observed 8.125 mean number of alleles, 0.640 mean observed heterozygosity (Ho) and 0.747 mean expected heterozygosity (He). Two loci showed significant deviations from Hardy-Weinberg equilibrium. Overall, the described loci were characterized by a moderately highlevel of polymorphism suggesting that these markers are useful for a population genetic studyin the Caribbean Sea.
Ilkka Hanski and Small Mammals: from Shrew Metapopulations to Vole and Lemming Cycles
2017
10 pages; International audience; Ilkka Hanski may be best known for his work on insect and metapopulation dynamics, but he also contributed significantly to small mammal research. In the early 1980s he became interested in shrew dynamics, energetics, and of course, shrew metapopulations. He aimed at understanding the population biological consequences of body size in different shrew species. Feeding habits and environmental stochasticity affect shrew species in profoundly different ways: due to their short survival time small species have high extinction rates but their dispersal and colonization capacity is high which enables them to survive as metapopulations. After Hansson and Henttonen…
Fine-Scale Population Differences in Atlantic Cod Reproductive Success: A Potential Mechanism for Ecological Speciation in a Marine Fish
2018
Abstract Successful resource‐management and conservation outcomes ideally depend on matching the spatial scales of population demography, local adaptation, and threat mitigation. For marine fish with high dispersal capabilities, this remains a fundamental challenge. Based on daily parentage assignments of more than 4,000 offspring, we document fine‐scaled temporal differences in individual reproductive success for two spatially adjacent (<10 km) populations of a broadcast‐spawning marine fish. Distinguished by differences in genetics and life history, Atlantic cod (Gadus morhua) from inner‐ and outer‐fjord populations were allowed to compete for mating and reproductive opportunities. After …