Search results for " nematode"
showing 10 items of 23 documents
Investment in multiple defences protects a nematode-bacterium symbiosis from predation
2017
The act of predation often comprises multiple sequential steps whereby prey can employ defences at all or some of these stages to deter predation. However, investment in defences is costly unless they are outweighed by conferring some benefit to the bearer. One system that employs multiple defences is that of the entomopathogenic nematode Heterorhabditis bacteriophora and its symbiotic bacterium Photorhabdus luminescens. This nematodeebacterium complex infects and kills soil-dwelling insect larvae, in which they then reproduce and juveniles emerge 2 weeks later. Predation of the infected host cadaver at any point during infection is fatal for the parasitic colony inside. Infected individual…
Integrated management strategies of Meloidogyne incognita and Pseudopyrenochaeta lycopersici on tomato using a Bacillus firmus-based product and two …
2019
Abstract Because of the restrictions on chemical pesticide use and their negative effects on the environment, as well as on human and animal health, alternative strategies for plant pest and pathogen managements are highly desirable. The objective of this work was to evaluate the suitability of a commercial formulation of Bacillus firmus strain 1-1582, applied either alone or in combination with oxamyl or fosthiazate, to control the southern root-knot nematode Meloidogyne incognita and the fungal plant pathogen Pseudopyrenochaeta lycopersici under greenhouse conditions during two tomato crop cycles. Application of B. firmus suppressed nematode population levels during the second crop cycle …
Dogs and Guinea worm eradication
2016
After 30 years of control campaigns, guinea worm faces eradication. However, dogs are expected to thwart the eradication of dracunculiasis as they act as alternative hosts of the worm. The health community un doubtedly have to recognise the success of the Guinea Worm Eradication Program (GWEP), although some flaws cannot be overlooked. One of the most essential points when trying to achieve the control of parasitic infections is to determine the role of reservoirs that could maintain the disease. Erroneously, dogs are likely to have been ignored as reservoirs of Dracunculus medinensis so far. I fi nd it hard to believe that a parasite that has always been considered specific to humans is ab…
The Guinea Worm: A Zoonotic Parasite of Dogs
2017
Inhabiting plant roots, nematodes, and truffles—polyphilus, a new helotialean genus with two globally distributed species
2018
Fungal root endophytes, including the common group of dark septate endophytes (DSEs), represent different taxonomic groups and potentially diverse life strategies. In this study, we investigated two unidentified helotialean lineages found previously in a study of DSE fungi of semiarid grasslands, from several other sites, and collected recently from a pezizalean truffle ascoma and eggs of the cereal cyst nematode Heterodera filipjevi. The taxonomic positions and phylogenetic relationships of 21 isolates with different hosts and geographic origins were studied in detail. Four loci, namely, nuc rDNA ITS1-5.8S-ITS2 (internal transcribed spacer [ITS]), partial 28S nuc rDNA (28S), partial 18S nu…
CARATTERIZZAZIONE METAGENOMICA di MICRORGANISMI E ORGANISMI DEL TERRENO PER UN LORO UTILIZZO COME AGENTI di LOTTA BIOLOGICA CONTRO NEMATODI FITOPARAS…
2014
La microflora della rizosfera riveste un ruolo fondamentale sia nella difesa che nello sviluppo e crescita delle piante. Molti studi hanno dimostrato inoltre che i nematodi sono in grado d’influenzarne la composizione. I batteri a loro volta producono una varietà di composti (antibiotici, nutrienti, esoenzimi e altre molecole segnale), in grado d’indurre ulteriori cambiamenti. L’obiettivo di questo lavoro è stato quello di studiare i cambiamenti nella biodiversità della microflora batterica di un terreno proveniente da un’azienda biologica, conseguenti all'introduzione sperimentale di larve di Meloidogyne incognita e al trattamento con un nematocida (fenamifos). Seguendo un approccio metage…
Shifts in size, genetic structure and activity of the soil denitrifier community by nematode grazing
2010
International audience; Bacterial-feeding nematodes represent an important driver of the soil microbial activity and diversity. This study aimed at characterizing the impact of nematode grazing on a model functional bacterial guild involved in N-cycling, the denitrifiers. Bacterial-feeding nematodes (Cephalobus pseudoparvus) were inoculated into soil microcosms whose indigenous nematofauna had previously been removed. The size, genetic structure and activity of the soil denitrifier community were characterized 15 and 45 days after nematodes inoculation using quantitative PCR of the nirK, nirS and nosZ denitrification genes, fingerprinting of the nirK and nirS genes and denitrification enzym…
Entomopatogēno nematožu Steinernema feltiae (Filipiev 1934) sastopamības novērtējuma aprobācija pēc Galleria mellonella metodes, to populācijas izmai…
2020
Darbā kalibrēta vienkārša, kvantitatīva metode entomopatogēno nematožu Steinernema feltiae (Filipiev, 1934) sastopamības novērtēšanai izmantojot Galleria mellonella (Linnaeus, 1758) kāpurus kā ēsmu. G. mellonella ēsmas tests tika kalibrēts divu dažāda vecuma sterilizētas kokosa šķiedras substrātā, kur tika konstatēta būtiska korelācija starp S. feltiae indivīdu blīvumu un G. mellonella mirstību 48h laikā gan svaigā (p<0.01, r=0.86, n=25), gan trīs gadus lietotajā (p<0.01, r=0.85, n=25) substrātā. Piecu nedēļu laikā dažāda vecuma rožu stādījumos ievāktos paraugos reģistrētas atšķirības pētījumā iesaistīto taksonu sastāvā, konstatēta S. feltiae telpiskās izplatības heterogenitāte, ilgstoša sa…
Sustainable Weed, Disease and Pest Management in Medicinal and Aromatic Plants
2015
As for all other crops, in MAPs as well, weeds, diseases and pests are important yield-reducing factors, which may severely curtain biomass production and, that is maybe more important, may affect several qualitative aspects of production. Research about this topic is generally lacking, for two main reasons: the first is that MAPs are generally grown on rather limited areas, and the incidence of specific pests and diseases rarely takes a relevance outside rather narrow boundaries. The second reason is that the economical importance of MAPs is much lower than that ascribed to the “major” crops, which the bigger efforts of research are addressed to. In the changing scenario of latter years, h…
Biological Responses of <I>Rhynchophorus ferrugineus</I> (Coleoptera: Curculionidae) to <I>Steinernema carpocapsae</I> (Nemat…
2013
Rhynchophorus ferrugineus (Olivier 1790) (Coleoptera: Curculionidae) is becoming a serious problem in Mediterranean areas where it is well-adapted, and now is present even in the United States (California). The infestations are primarily in urban areas where chemical control is not advisable and million of Euros are spent to control it. The effects of the entomopathogenic nematode Steinernema carpocapsae (Nematoda: Steinernematidae) on mortality, growth, as well as the immune activity of R. ferrugineus larvae, were investigated. R. ferrugineus mortality exhibited a positive trend with the dosage and duration of exposure to S. carpocapsae. The median lethal dose and median lethal time, impor…