Search results for "GRI"
showing 10 items of 10209 documents
Impact of genetic diversity of an earthworm on decomposition and ecosystem functioning
2020
Abstract Ecosystem functioning is affected positively by increased biodiversity, through complementary functions of multiple species or because high-functioning species are more likely in a species-rich community. Genetic diversity is one level of biodiversity that has been shown to positively affect ecosystem functioning. Whether the genetic diversity of a key decomposer species affects decomposition processes, and ecosystem functioning in general, is still unknown. We compared low and high genetic diversity assemblages of the earthworm Dendrobaena octaedra in two different experiments: using microcosms containing a simple community of other decomposer animals (some nematodes and other mic…
Genetic diversity of fig (Ficus caricaL.) genotypes grown in Southern Italy revealed by the use of SSR markers
2017
The genetic variability among 181 fig (Ficus carica L.) accessions found in small farms located in Campania, Basilicata, Apulia, Calabria and Sicily was investigated analysing the polymorphism of 18 simple sequence repeat (SSR) markers. The SSR analysis revealed a large genetic diversity among accessions. A total of 117 alleles were detected with a mean of 6.5 locus-1. The average expected (He) and observed heterozygosity (Ho) were 0.56 and 0.66, respectively. The mean polymorphic information content (PIC) was 0.51, suggesting a significant molecular diversity among the fig accessions taken into consideration. The UPGMA cluster analysis discriminated 174 genotypes and allowed to find 8 grou…
THE DISTRIBUTION OF MUTATIONAL FITNESS EFFECTS OF PHAGE φX174 ON DIFFERENT HOSTS
2012
Adaptation depends greatly on the distribution of mutation fitness effects (DMFE), but the phenotypic expression of mutations is often environment dependent. The environments faced by multihost pathogens are mostly governed by their hosts and therefore measuring the DMFE on multiple hosts can inform on the likelihood of short-term establishment and longer term adaptation of emerging pathogens. We explored this by measuring the growth rate of 36 mutants of the lytic bacteriophage φX174 on two host backgrounds, Escherichia coli (EcC) and Salmonella typhimurium (StGal). The DMFE showed higher mean and variance on EcC than on StGal. Most mutations were either deleterious or neutral on both host…
EVALUATION OF ELEVATED PLOIDY AND ASEXUAL REPRODUCTION AS ALTERNATIVE EXPLANATIONS FOR GEOGRAPHIC PARTHENOGENESIS IN EUCYPRIS VIRENS OSTRACODS
2009
Transitions from sexual to asexual reproduction are often coupled with elevations in ploidy. As a consequence, the importance of ploidy per se for the maintenance and spread of asexual populations is unclear. To examine the effects of ploidy and asexual reproduction as independent determinants of the success of asexual lineages, we sampled diploid sexual, diploid asexual, and triploid asexual Eucypris virens ostracods across a European wide range. Applying nuclear and mitochondrial markers, we found that E. virens consists of genetically highly differentiated diploid sexual populations, to the extent that these sexual clades could be considered as cryptic species. All sexual populations wer…
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…
Morphological and Physiological Root Traits and Their Relationship with Nitrogen Uptake in Wheat Varieties Released from 1915 to 2013
2021
Identifying genotypes with a greater ability to absorb nitrogen (N) may be important to reducing N loss in the environment and improving the sustainability of agricultural systems. This study extends the knowledge of variability among wheat genotypes in terms of morphological or physiological root traits, N uptake under conditions of low soil N availability, and in the amount and rapidity of the use of N supplied with fertilizer. Nine genotypes of durum wheat were chosen for their different morpho-phenological characteristics and year of their release. The isotopic tracer 15N was used to measure the fertilizer N uptake efficiency. The results show that durum wheat breeding did not have univ…
Artificial germination activation of Dialium corbisieri by imitation of ecological process.
2013
11 pages; International audience; Species of the gender Dialium commonly are trees found in Central African rainforests. They produce tasty sugary fruits, feeding numerous frugivores, but are, despite their valuable nutritional value, rarely exploited by humans. A potential reason for this could be the complexity of symbiotic dependence between trees and pollinators, germination activators, and dispersers causing problems in ancestral and contemporary domestication. We investigated Dialium corbisieri reproduction in the Democratic Republic of the Congo, Bandundu Province. Here we give a key for an artificial activation of germination of these trees ecologically adapted to the digestive syst…
Grazing and abandonment determine different tree dynamics in wood-pastures
2016
Wood-pastures are threatened biotopes in which trees and livestock grazing maintain high conservation values. However, browsing may threaten tree regeneration, whereas abandonment leads to tree encroachment. We studied the regeneration of trees in a grazed and abandoned boreal wood-pastures. In grazed sites, the density of young spruces (Picea abies) was high, while the density of young birches (Betula spp.) was very low. Sprucification can be prevented only by removing spruces. The number of young birches and pines (Pinus sylvestris) was correlated with the number of junipers (Juniperus communis), probably because thorny junipers protect palatable seedlings from browsing. In abandoned site…
Identification of (In)Compatible S-genotypes and Molecular Characterisation of Italian Sweet Cherry Cultivars.
2017
Italy is the first sweet cherry producer in Europe. Its rich germplasm of local varieties has not been fully characterised or exploited in breeding programmes. Sweet cherry is a self-incompatible species; this trait is controlled by a gametophytically expressed multi-allelic (S) locus. The knowledge of sweet cherry S-alleles and cross-incompatibility groups is important for growers and breeders for choosing appropriate pollinators in the orchard and planning crosses. In this work, we analysed 94 sweet cherry cultivars native of large part of the Italian regions where cherry is grown. The microsatellite primer pair set and the reference cultivars agreed for cherry by the Prunus Working Group…
New Clones and Old Varieties: Quality of Sicilian Hillside Apple Cultivation
2021
Aims: The aim of this study is to evaluate the qualitative characteristics of the new clones according to the Mediterranean hillside growing environment and, at the same time, to highlight the qualitative peculiarities of the old varieties in order to avoid genetic loss. Introduction: Several apple varieties are constantly selected for improved quality traits and introduced for cultivation and marketing in addition to a few traditional and affirmed varieties. On the other side, local genotype and ancient varieties are still valorised due to the request of a niche market. Methods: We have studied the physico-chemical quality and the sensory traits of the fruit obtained in this particular en…