Efecto de cadáveres de Galleria mellonella infectados con Heterorhabditis bacteriophora y Steinernema rarum, sus macerados y juveniles infectantes muertos en la supresión de Meloidogyne javanica

Nematodes of the Meloidogyne genus affect to most of crops of an economic importance in Argentina. Researches related to new control strategies are needed to reduce the damage produced by these organisms. The objective of this work was to compare the effects of Galleria mellonella cadavers infected with the Argentine isolates Heterorhabditis bacteriophora Rama Caída and Steinernema rarum NOE, cadaver macerates and dead infective juveniles (IJs) on M. javanica suppression. Experiments were performed using 24-well plates and pepper plants grown in a growth chamber. The entomopathogenic nematodes-infected G. mellonella cadavers, their cadaver macerates and dead IJs were effective in suppressing M. javanica second-stage juveniles under laboratory conditions. The use of H. bacteriophora-infected cadavers caused a significant decrease in the number of galls and egg masses on pepper plants parasitized by M. javanica, in a growth-chamber.Nematodos del género Meloidogyne afectan a la mayoría de los cultivos de importancia económica en Argentina. Investigaciones relacionadas con nuevas estrategias de control son necesarias para reducir el daño ocasionado por estos organismos. El objetivo de este trabajo fue comparar el efecto de cadáveres de Galleria mellonella infectados con los aislados argentinos Heterorhabditis bacteriophora Rama Caída y Steinernema rarum NOE, sus macerados y juveniles infectantes (JIs) muertos en la supresión de M. javanica. Las experiencias fueron conducidas utilizando placas de cultivo de 24 pozos y plantas de pimiento que crecieron en cámara de crecimiento. Los cadáveres infectados, sus macerados y JIs muertos fueron efectivos en suprimir juveniles de segundo estadio de M. javanica en las experiencias de laboratorio. En cámara de crecimiento, el uso de cadáveres infectados con H. bacteriophora causó reducción en el número de agallas y masas de huevos en plantas de pimiento parasitadas por M. javanica.Fil: Del Valle, Eleodoro Eduardo. Universidad Nacional del LitoralFil: Doucet, Marcelo Edmundo. Consejo Nacional de Investigaciones Científicas y Técnica

Efecto de cadáveres de Galleria mellonella infectados con Heterorhabditis bacteriophora y Steinernema rarum, sus macerados y juveniles infectantes muertos en la supresión de Meloidogyne javanica

Nematodes of the Meloidogyne genus affect to most of crops of an economic importance in Argentina. Researches related to new control strategies are needed to reduce the damage produced by these organisms. The objective of this work was to compare the effects of Galleria mellonella cadavers infected with the Argentine isolates Heterorhabditis bacteriophora Rama Caída and Steinernema rarum NOE, cadaver macerates and dead infective juveniles (IJs) on M. javanica suppression. Experiments were performed using 24-well plates and pepper plants grown in a growth chamber. The entomopathogenic nematodes-infected G. mellonella cadavers, their cadaver macerates and dead IJs were effective in suppressing M. javanica second-stage juveniles under laboratory conditions. The use of H. bacteriophora-infected cadavers caused a significant decrease in the number of galls and egg masses on pepper plants parasitized by M. javanica, in a growth-chamber.Nematodos del género Meloidogyne afectan a la mayoría de los cultivos de importancia económica en Argentina. Investigaciones relacionadas con nuevas estrategias de control son necesarias para reducir el daño ocasionado por estos organismos. El objetivo de este trabajo fue comparar el efecto de cadáveres de Galleria mellonella infectados con los aislados argentinos Heterorhabditis bacteriophora Rama Caída y Steinernema rarum NOE, sus macerados y juveniles infectantes (JIs) muertos en la supresión de M. javanica. Las experiencias fueron conducidas utilizando placas de cultivo de 24 pozos y plantas de pimiento que crecieron en cámara de crecimiento. Los cadáveres infectados, sus macerados y JIs muertos fueron efectivos en suprimir juveniles de segundo estadio de M. javanica en las experiencias de laboratorio. En cámara de crecimiento, el uso de cadáveres infectados con H. bacteriophora causó reducción en el número de agallas y masas de huevos en plantas de pimiento parasitadas por M. javanica

Morphology and DNA sequence data reveal the presence of Globodera ellingtonae in the Andean region

Potato cyst nematodes, G. rostochiensis and G. pallida, are the most economically important nematode pests of potatoes worldwide and are subject to strict quarantine regulations in many countries. Globodera ellingtonae was recently described from Oregon (USA), with its host-plant in the field being still unknown. Roots of Andean potatoes from the North of Argentina have been found attacked by this nematode, providing further evidence that this is a potato cyst nematode species, along with G. pallida and G. rostochiensis. New information about morphological, biological and molecular aspects of G. ellingtonae is provided for diagnostic purposes. The Argentine population showed morphological differences from specimens from Oregon; therefore, new diagnostic characters were defined to differentiate G. ellingtonae from its closest species. The Hsp90 gene was shown to be a good diagnostic marker for discriminating the three PCN species. The importance of the detection of G. ellingtonae on potatoes in the Andean region is not restricted to a regional level, since the nematode is also present in USA. This species can pose a serious problem to potato crop, especially when infected tubers are used as seeds. The distribution in the South American Andes is likely to extend the currently known distribution areas because cysts are passively transported. There is a need to evaluate the possible damage it may cause to potato crops. Morphological and molecular diagnoses conducted in this work provide fundamental information for the protection of potato crops not only in those countries in the Americas where the species has already been detected, but also worldwide.Fil: Lax, Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Rondan Dueñas, Juan. Provincia de Córdoba. Ministerio de Ciencia y Técnica. Centro de Excelencia En Productos y Procesos de Córdoba; ArgentinaFil: Franco Ponce, Javier. PROINPA Foundation; BoliviaFil: Gardenal, Cristina Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Doucet, Marcelo Edmundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin

Influence of two Nacobbus aberrans isolates from Argentina on the growth of three tomato cultivars

Nacobbus aberrans ataca tanto malezas como plantas cultivadas, causando drásticas pérdidas en el rendimiento de los cultivos. ʻSupermanʼ y ʻMykonosʼ son cultivares de tomate redondo comercializados como resistentes a nematodos, aunque no se especifica a qué especie/s, ni hay estudios acerca de su respuesta ante la infección con N. aberrans. En este trabajo analizamos la influencia de dos aislados argentinos del nematodo (Lules y Río Cuarto) en el crecimiento de Superman y Mykonos; se utilizó como control positivo al cultivar Platense que es susceptible al parásito. Se midieron variables de crecimiento, cantidad de agallas y masas de huevos por sistema radical y tamaño de las agallas. En el cultivar Mykonos disminuyó el diámetro del tallo cuando se infectó con el aislado Lules; en Superman, las plantas infectadas evidenciaron menor peso seco aéreo que las sanas. No se encontraron diferencias significativas para las variables de crecimiento en el cultivar Platense, aunque fue el que presentó las agallas de mayor tamaño. El aislado proveniente de Lules fue más agresivo que el de Río Cuarto, generando mayor cantidad de agallas y masas de huevos en Mykonos y Platense que en Superman. Los cultivares evaluados fueron hospedadores eficientes del parásito, por lo que no pueden considerarse resistentes a los aislados utilizados.Nacobbus aberrans attacks weeds and cultivated plants, causing drastic crop yield losses. Thetomatoes ʻSupermanʼ and ʻMykonosʼ are marketed as nematode resistant, but with no specifications of the nematode species. Moreover, no studies have recorded the response of these cultivars to infection by N. aberrans. We analyzed the influence of two Argentine isolates of N. aberrans (Lules and Río Cuarto) on the growth of these cultivars and Platense, a known susceptible used as a positive control. Plant growth variables, number of galls and egg masses, and gall size were measured. Mykonos infected with the Lules isolate exhibited a decrease in stem diameter. In Superman, all infected plants showed reduced shoot dry weight. Platense did not show differences (P>0.05) in growth variables between treated and control plants, however, this cultivar showed the largest galls. The Lules isolate was more aggressive than the Rio Cuarto isolate and produced a greater number of galls and egg masses on Mykonos and Platense than on Superman.These findings indicate that Superman and Mykonos were efficient hosts of N. aberrans and cannot be considered resistant to either of the two nematode isolatesFil: Cabrera, Verónica Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Dottori, Nilda Mirta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Doucet, Marcelo Edmundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin

Effects of insect cadavers infected by Heterorhabditis bacteriophora and Steinernema diaprepesi on Meloidogyne incognita parasitism in pepper and summer squash plants

E. E. Del Valle, P. Lax, J. Rondán Dueñas, and M. E. Doucet. 2013. Effects of insect cadavers  infected  by  Heterorhabditis  bacteriophora  and  Steinernema  diaprepesi  on Meloidogyne incognita parasitism in pepper and summer squash plants.  The effects of insect cadavers infected with three isolates of Heterorhabditis bacteriophora and one isolate of Steinernema diaprepesi on a population of Meloidogyne incognita  in  pepper  (Capsicum  annuum)  and  summer  squash  (Cucurbita  maxima)  were evaluated in greenhouse experiments carried out in Santa Fe (Argentina). Insect cadavers were obtained for the experiments from last instar larvae of Galleria mellonella and Tenebrio molitor  that had  been  infected  with  entomopathogenic nematodes.  Two  six-day-old  insect cadavers per pot were placed below the soil surface, and the soil was inoculated with 100 second-stage juveniles of M. incognita. Sixty days after inoculation, the following parameters were recorded for each plant: number of leaves; dry weight of aerial parts; numbers of galls, egg masses and eggs; and numbers of galls, egg masses and eggs g -1  of root fresh matter. In pepper, the only variable affected by the infected cadavers with respect to control was the number of eggs in the treatment involving T. molitor cadavers infected with the H. bacteriophora isolate Rama  Caída.  In  summer  squash,  several  treatments  using  infected  cadavers  resulted  in  a decrease in the numbers of galls and egg masses. Only the treatment involving G. mellonella cadavers infected with the H. bacteriophora isolate Rama Caída proved to be efficient in reducing the number of M. incognita eggs. Our results indicated that the application of insect cadavers infected with the entomopathogenic nematodes studied might reduce M. incognita damage in pepper and summer squash plants.Fil: del Valle, Eleodoro Eduardo. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina;Fil: Lax, Paola. Consejo Nacional de Invest.cientif.y Tecnicas. Centro Cientifico Tecnol.conicet - Cordoba. Instituto de Diversidad y Ecologia Animal; Argentina;Fil: Rondan Dueñas, Juan. Provincia de Cordoba. Ministerio de Ciencia y Tecnica. Centro de Excelencia En Productos y Procesos de Cordoba; Argentina;Fil: Doucet, Marcelo Edmundo. Consejo Nacional de Invest.cientif.y Tecnicas. Centro Cientifico Tecnol.conicet - Cordoba. Instituto de Diversidad y Ecologia Animal; Argentina

Susceptibility of Spodoptera frugiperda and Helicoverpa gelotopoeon (Lepidoptera: Noctuidae) to the entomopathogenic nematode Steinernema diaprepesi (Rhabditida: Steinernematidae) under laboratory conditions

Spodoptera frugiperda Smith and Helicoverpa gelotopoeon (Dyar) are important agricultural pests ofseveral crops. The aim of the present work was to evaluate the susceptibility of larvae of both insects to an isolate of Steinernema diaprepesi Nguyen & Duncan under laboratory conditions, as well as the capacity of the nematode to multiply on the lepidoterans. Larvae (n = 15) were exposed to 0 (control), 50, and 100 infective juveniles (IJs) per Petri dish. Mortality was evaluated every 24 h during 6 d, and emerging IJs were counted. Mortality of S. frugiperda was 93% and 100% with 50 and 100 IJs dosage, and 87% and 93% in H. gelotopoeon, respectively. The production of IJs was significantly different between doses (P ≤ 0.05) for S. frugiperda (11 329 with 50 IJs vs. 27 155 with 100 IJs) but not for H. gelotopoeon 19 830 vs. 26 361, respectively). This is the first study evaluating the susceptibility of these lepidopterans to S. diaprepesi. These results encourage the possibility of using this nematode for biological control of both pests.Fil: Caccia, Milena Guadalupe. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; ArgentinaFil: del Valle, Eleodoro Eduardo. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; ArgentinaFil: Doucet, Marcelo Edmundo. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; ArgentinaFil: Lax, Paola. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; Argentin

Response of different potato cultivars to the presence of Nacobbus aberrans.

Nacobbus aberrans occurs in temperate and subtropical areas of South and North America. In Argentina, the species is widely distributed although accurate knowledge of the host range is unknown for many populations. In this work the reproductive capacity of three Argentine populations of different geographical origin was evaluated on four potato cultivars (Spunta, Kennebec, Colorada, and Asterix); histological studies were conducted on root tissues of inoculated plants from each cultivar. Two N. aberrans populations from Córdoba province were not able to reproduce on those cultivars; no evidence of the nematode presence was detected in root tissues. The remaining population, which was from Catamarca province, induced gall formation in all cultivars. Histological studies showed hyperplastic parenchymatous tissue occupying the central cylinder of invaded roots. In the same zone, syncytia developed closely associated with females of the nematode. The results showed different responses of potato cultivars to the presence of the N. aberrans populations.Fil: Lax, Paola. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; ArgentinaFil: Tordable, María del Carmen. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquimicas y Naturales; ArgentinaFil: Macagno, Javier. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquimicas y Naturales; ArgentinaFil: Bima, Paula. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; ArgentinaFil: Doucet, Marcelo Edmundo. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; Argentin

Morphological and molecular characterisation of the entomoparasitic nematode Hammerschmidtiella diesingi (Nematoda, Oxyurida, Thelastomatidae)

A population of Hammerschmidtiella diesingi was detected in specimens of Periplaneta americana collected in Córdoba city (Argentina) was studied. Nematodes were characterized based on morphological, morphometric and genetic (D2-D3 expansion segment) analyses. New data are provided, especially on particular morphological characters that were a matter of controversy in previous studies. H. diesingi is reported in Argentina for the first time. © 2012 Versita Warsaw and Springer-Verlag Wien.Fil: Blanco, María Victoria. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; ArgentinaFil: Lax, Paola. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Rondan Dueñas, Juan. Provincia de Córdoba. Ministerio de Ciencia y Técnica. Centro de Excelencia en Productos y Procesos de Córdoba; ArgentinaFil: Gardenal, Cristina Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Doucet, Marcelo Edmundo. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin

Effect of the entomopathogenic nematode-bacterial symbiont complex on Meloidogyne hapla and Nacobbus aberrans in short-term greenhouse trials

Meloidogyne hapla and Nacobbus aberrans are plant-parasitic nematodes that form galls in the roots of infected plants and cause important economic losses. Entomopathogenic nematodes (EPNs) of the genera Steinernema and Heterorhabditis infect and kill insects via toxins produced by their symbiotic bacteria. EPNs have shown to have an antagonistic effect on different plant-parasitic nematode species in field and greenhouse trials. The aim of the present work was to evaluate, in tomato plants in greenhouse, the effect of the application of three Argentine EPN isolates, their symbiotic bacteria and cell-free supernatants, on a population of M. hapla and two populations of N. aberrans. Sixty days after inoculation, the number of galls and egg masses, the nematode reproduction factor (RF) and plant biomass were calculated. With a few exceptions, biomass was not affected by the different treatments. None of the plant-parasitic nematode populations was reduced by infective juvenile inoculation of the different EPN isolates. Bacterial action differed among populations; M. hapla was the most susceptible one, with a significant reduction in the number of galls, egg masses and RF caused by the application of the three bacterial strains. The most significant effect was produced by the cell-free supernatants on nematode RF, with reductions of 62–90%, caused by bacterial metabolites. The different inoculation alternatives of the EPN-bacterial symbiont complex tested in the present work (infective juveniles, bacteria and cell-free supernatant) are compared for the first time for plant-parasitic nematode species.Fil: Caccia, Milena Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Marro, Nicolás Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Rondan Dueñas, Juan. Pabellón CEPROCOR. Laboratorio de Biología Molecular; ArgentinaFil: Doucet, Marcelo Edmundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Lax, Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin

Use of the arbuscular mycorrhizal fungus <i>Glomus intraradices</i> as biological control agent of the nematode <i>Nacobbus aberrans</i> parasitizing tomato

The plant-parasitic nematode Nacobbus aberrans is an endoparasite that induces gall formation in the roots and causes severe losses to diverse crops. Some populations of this nematode show preference for certain hosts, revealing the existence of "races/groups" with different behaviour and making nematode management difficult. A possible biological control alternative to reduce the damage caused by this species may be the use of arbuscular mycorrhizal fungi (AMF). In the present work, the effect of Glomus intraradices on tomato plants inoculated with the nematode at transplanting and three weeks later was tested. At 60 days, the following parameters were estimated: percentage of AMF colonization, root and aerial dry weight, number of galls and egg masses, and reproduction factor (RF=final population/initial population) of N. aberrans. AMF colonization was higher in the presence of the nematode. The use of AMF favoured tomato biomass and reduced the number of galls and RF on the plants inoculated with the nematode at transplanting.Facultad de Ciencias Naturales y MuseoInstituto de Botánica "Dr. Carlos Spegazzini