Search results for "cult"
showing 10 items of 25905 documents
Colonization of flax roots and early physiological responses of flax cells inoculated with pathogenic and nonpathogenic strains of Fusarium oxysporum
2003
ABSTRACT Fusarium oxysporum includes nonpathogenic strains and pathogenic strains that can induce necrosis or tracheomycosis in plants. The objective of this study was to compare the abilities of a pathogenic strain (Foln3) and a nonpathogenic strain (Fo47) to colonize flax roots and to induce early physiological responses in flax cell culture suspensions. Both strains colonized the outer cortex of the root; however, plant defense reactions, i.e., the presence of wall appositions, osmiophilic material, and collapsed cells, were less frequent and less intense in a root colonized by Foln3 than by Fo47. Early physiological responses were measured in flax cell suspensions confronted with germin…
Cause and duration of mustard incorporation effects on soil-borne plant pathogenic fungi
2009
International audience; Two fungal plant pathogens, Rhizoctonia solani AG 2-2 and Fusarium oxysporum f.sp. lini, were studied in relation to general responses of soil fungi and bacteria following incorporation of Brassica juncea. Our aim was to understand to what extent the changes in the biological and physicochemical characteristics of the soil could explain the effects on the studied pathogens and diseases, and to determine the temporal nature of the responses. Short-term effects of mustard incorporation (up to 4 months) were investigated in a microcosm experiment, and compared with a treatment where composted plant material was incorporated. In a field experiment, the responses were fol…
Shifts in the structure of rhizosphere bacterial communities of avocado after Fusarium dieback
2021
The rhizosphere microbiome is critical for plant growth and protection against plant pathogens. However, rhizosphere microbial communities are likely to be restructured upon plant infection by fungal pathogens. Our objective was to determine the shifts in rhizosphere bacterial communities of avocado trees (Persea americana Mill.) after Fusarium dieback (FD), a disease triggered by the symbiotic fungi of invasive ambrosia beetles (Euwallacea kuroshio and Euwallacea sp. nr. fornicatus), using 16S rDNA gene amplicon sequencing and a culture-dependent approach. Rhizosphere soil samples were collected from five asymptomatic and five FD-symptomatic avocado trees in a Californian orchard. Sequence…
Isolation and characterization of nonpathogenic Fusarium oxysporum isolates from the rhizosphere of healthy banana plants
2006
Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; One of the most serious diseases of banana is fusarium wilt, caused by Fusarium oxysporum f.sp. cubense (Foc). The objectives of this study were to isolate and identify nonpathogenic F. oxysporum strains from soils suppressive to banana wilt, and to determine the diversity of these isolates. More than 100 Fusarium strains were isolated from the rhizosphere of banana plants and identified to species level. Pathogenicity testing was carried out to confirm that these isolates were nonp…
Genetic structure and molecular variability of grapevine fanleaf virus in sicily
2021
Grapevine fanleaf virus (GFLV) is one of the main causes of grapevine fanleaf degeneration disease (GFDD) and is present in almost all areas where grapevine is cultivated. In this work, we ascertained the presence and spread of GFLV in different commercial vineyards in four Sicilian provinces (Italy), and its genetic structure and molecular variability were studied. In detail, a total of 617 grapevine samples of 11 autochthonous grapevine cultivars were collected in 20 commercial vineyards. Preliminary screening by serological (DAS-ELISA) and molecular (RT-PCR) analyses for ArMV (arabis mosaic virus) and GFLV detection were conducted. Results obtained showed the absence of ArMV in all the s…
A review on introduced alien insect pests and their associated parasitoids on eucalyptus trees in Sicily
2018
A review is reported in the present paper on invasive alien insects introduced in Sicily on Eucalyptus trees, together with unpublished results from recent surveys. As to the latter ones, observations were conducted especially on Thaumastocoris peregrinus (Carpintero & Dellapé) (Hemiptera, Thaumastocoridae), the most recently introduced species. Overall, eight alien insect pests have been accidentally introduced in the island on Eucalyptus, belonging to the orders Hemiptera (Aphalaridae, 2 spp.; Thaumastocoridae, 1 sp.), Coleoptera (Cerambycidae, 2 spp.; Curculionidae, 1 sp.) and Hymenoptera (Eulophidae, 2 spp.). Two encyrtid parasitoids, Avetianella longoi Siscaro and Psyllaephagus bliteus…
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…