Utilización de Trichoderma spp. en el control de la podredumbre de raíz y cuello de espárrago

456 páginasLa podredumbre de raíz y cuello (PRC) producida por diversas especies del género Fusarium es una de las principales enfermedades del espárrago (Asparagus officinalis L.), provocando importantes pérdidas de producción. Para evaluar la capacidad antagonista de cuatro aislados de Trichoderma spp. (TGr1.41, T108, T25/99 y T11) frente a Fusarium oxysporum f.sp. asparagi (Foa) y Fusarium solani (Fs) en 2009 se llevaron a cabo cuatro experimentos en umbráculo en dos localidades: Alcalá del Río (Sevilla) y Chipiona (Cádiz). Se utilizaron contenedores de 100 l de capacidad infestados con Foa o Fs (103- 105 UFC/g suelo) en los cuales se sembraron cuatro plantas del cultivar de espárrago Grande, susceptible a la enfermedad. Previamente a su plantación, las plantas fueron tratadas mediante inmersión de sus raíces en una dilución de Trichoderma spp. (107 conidias/ml) y, tras su plantación, mediante aportes mensuales de los mismos aislados incrementados en granos de trigo. Al finalizar el ensayo se determinó el peso fresco de las raíces y se cuantificó la densidad de Trichoderma spp. en la rizosfera. En todos los experimentos se obtuvieron niveles bajos de enfermedad, debido posiblemente a la baja densidad de inóculo en el sustrato antes de la plantación y a condiciones ambientales poco favorables para el desarrollo de la PRC. No se encontraron diferencias significativas entre las plantas tratadas con cualquiera de los aislados de Trichoderma spp. y las plantas testigo no tratadas, tanto en el conjunto de plantas inoculadas con Foa o Fs como en el de las no inoculadas. Sí se observó una interacción entre el aislado de T. atroviride (T11) con Foa y Fs, y el de T. asperellum (T108) con Fs, de forma que el peso de las plantas tratadas con dichos aislados fue significativamente mayor cuando se encontraron en contacto con los patógenos. El estudio de la colonización de la rizosfera por parte de Trichoderma spp. también mostró en algunos casos una interacción entre el agente de biocontrol y el patógeno: los aislados T11 y T108 colonizaron en mayor extensión la rizosfera de las plantas de espárrago que estuvieron en contacto con Foa y, con Foa y Fs, respectivamente, que las de las plantas tratadas no inoculadas.Peer reviewe

Organic amendments conditions on the control of Fusarium crown and root rot of asparagus caused by three Fusarium spp.

Fusarium oxysporum (Fo), F. proliferatum (Fp) and F. solani (Fs) are causal agents associated with roots of asparagus affected by crown and root rot, a disease inflicting serious losses worldwide. The propagule viability of Fusarium spp. was determined on substrate artificially infested with Fo5, Fp3or Fs2 isolates,amended with either poultry manure (PM), its pellet (PPM), or olive residue compost (ORC) and, thereafter, incubated at 30 or 35°C for different periods. Inoculum viability was significantly affected by these organic amendments (OAs) in combination with temperature and incubation period. The greatest reduction in viability of Fo5 and Fs2 occurred with PPM and loss of viability achieved was higher at 35°C than at 30ºC, and longer incubation period (45 days). However, the viability of Fp3 did not decrease greatly in most of the treatments, as compared to the infested and un-amended control, when incubated at 30ºC. After incubation, seedlings of asparagus `Grande´ were transplanted into pots containing substrates infested with the different species of Fusarium. After three months in greenhouse, symptoms severity in roots showed highly significant decreases, but Fp3 caused lower severity than Fo5 and Fs2. Severity reduction was particularly high at 30ºC (by 15 days incubation for Fs2 and by 30-45 days for Fo5), after PPM treatment, as well as PM-2% for Fo5and Fs2 incubated during 30 and 45 days at both temperatures, and with ORC (15-30 days incubation). Moreover, assessment of plants fresh weight showed significantly high increases in Fo5 and Fs2, with some rates of the three OAs tested, depending on incubation period and temperature.This research was funded by a JAEPredoc-CSIC grant to AIBB; Ministerio de Agricultura, Alimentación y Medio Ambiente, Spain (project INIA RTA 2006-00045); and Consejería de Economía, Innovación y Ciencia, Junta de Andalucía, Spain (Project P06-AGR-02313).Peer reviewe

Characterization of isolates of Fusarium spp. obtained from asparagus in Spain

11 pages; 7 tables; 4 figuresMicrobial analysis of asparagus plants (Asparagus officinalis) obtained from four nurseries in Spain in 2002 to 2003 indicated high frequencies of Fusarium proliferatum, F. oxysporum, and F. moniliforme in the rhizomes and storage roots. Out of 201 isolates of Fusarium obtained from nursery crowns and from plants sampled in nine established asparagus fields, the highest frequency of highly pathogenic isolates was observed from samples collected from fields, and included some extremely virulent isolates of F. solani. For isolates of low to moderate virulence, the percentage of those significantly (P = 0.01) associated with root dry weight loss was larger for F. proliferatum (53.8%) than for the other Fusarium species (10.3 to 23.1%). Random amplified polymorphic DNA (RAPD) analysis of 19 isolates of Fusarium spp. grouped all F. proliferatum and F. moniliforme isolates together and, in a second cluster, five of the eight isolates of F. oxysporum. Asparagus cultivars Verde-Morado and Dariana were the least susceptible of 11 cultivars commonly grown in Spain; isolates of F. solani and F. moniliforme proved highly virulent; and a significant interaction was observed among pathogen isolates and asparagus cultivars when representative pathogenic isolates of F. proliferatum, F. oxysporum, F. moniliforme, and F. solani were tested on those cultivars. Larger reductions in root dry weight were associated with F. proliferatum and F. solani than with F. oxysporum and F. moniliforme, and differences in root and stem dry weights among cultivars were significant.Ministerio de Agricultura, Pesca y Alimentación. Project INIA RTA 02-216. Spain IFAPA/ASOCIAFRUIT. Project CO-011. SpainPeer reviewe

Evaluación de la susceptibilidad de variedades comerciales de fresa A Fusarium solani

Póster presentado en el XVIII Congreso de la Sociedad Española de Fitopatología (SEF), celebrado en Palencia del 20 al 23 de septiembre de 2016.Recientemente se han referido en el cultivo de la fresa en España plantas con síntomas de enanismo, marchitez y muerte asociados con Fusarium solani (Fs). Existe un amplio número de cultivares de fresa, pero se desconoce su comportamiento frente a Fs. Se ha evaluado la reacción de 11 cultivares de fresa (‘Albión’, ‘Antilla’, ‘Benicia’, ‘Candonga’, ‘Fortuna’, ‘Primoris’, ‘Rábida’, ‘Sabrina’, ‘Sahara’, ‘San Andreas’ y ‘Ventana’) a la inoculación con un aislado de Fs de probada patogenicidad. Las plantas se inocularon por inmersión durante 30 min en una suspensión de 106 con/ml y se trasplantaron a macetas con un sustrato estéril. Las plantas se incubaron a 25ºC y 16h de luz durante tres meses. Se evaluó el porcentaje de raíces nuevas emitidas, los estolones y frutos producidos, la proporción de corona afectada, el porcentaje de plantas muertas y el peso fresco de cada planta. En todos los cultivares se observaron los síntomas asociados con Fs. Todas las plantas de ‘Antilla’, ‘Sahara’ y ‘Benicia’ murieron al finalizar el experimento, no así las de ‘Candonga’, ‘Primoris’ y ‘San Andreas’ en las que no murió ninguna planta. En la producción de raíces nuevas hubo diferencias significativas entre cultivares y entre plantas testigos e inoculadas. Las plantas inoculadas de ‘Sabrina’ y ‘San Andreas’ emitieron un número significativamente menor de raíces que las testigo. Las coronas más afectadas se observaron en ‘Antilla’, ‘Sahara’ y ‘Benicia’, mientras las de ‘San Andreas’ fueron las más sanas. Los mayores pesos frescos se determinaron en ‘San Andreas’, ‘Candonga’, ‘Sabrina’ y ‘Primoris’, y fueron más de cinco veces los de ‘Sahara’, y más del doble que los de ‘Antilla’ y ‘Benicia’. En general, las plantas inoculadas tuviero pesos más bajos que las testigos, en particular en ‘Antilla’, ‘Primoris’ y ‘Candonga’.Financiación: INIA RTA 2013-00062-C05-02 y fondos FEDER 2014-2020: “Programa Operativo de Crecimiento Inteligente”.N

Characterization of Fusarium isolates from asparagus fields in southwestern Ontario and influence of soil organic amendments on Fusarium crown and root rot

Fusarium crown and root rot (FCRR) of asparagus has a complex etiology with several soilborne Fusarium spp. as causal agents. Ninetythree Fusarium isolates, obtained from plant and soil samples collected from commercial asparagus fields in southwestern Ontario with a history of FCRR, were identified as Fusarium oxysporum (65.5%), F. proliferatum (18.3%), F. solani (6.4%), F. acuminatum (6.4%), and F. redolens (3.2%) based on morphological or cultural characteristics and polymerase chain reaction (PCR) analysis with species-specific primers. The intersimple- sequence repeat PCR analysis of the field isolates revealed considerable variability among the isolates belonging to different Fusarium spp. In the in vitro pathogenicity screening tests, 50% of the field isolates were pathogenic to asparagus, and 22% of the isolates caused the most severe symptoms on asparagus. The management of FCRR with soil organic amendments of pelleted poultry manure (PPM), olive residue compost, and fish emulsion was evaluated in a greenhouse using three asparagus cultivars of different susceptibility in soils infested with two of the pathogenic isolates (F. oxysporum Fo-1.5 and F. solani Fs-1.12). Lower FCRR symptom severity and higher plant weights were observed for most treatments on 'Jersey Giant' and 'Grande' but not on 'Mary Washington'. On all three cultivars, 1% PPM consistently reduced FCRR severity by 42 to 96% and increased plant weights by 77 to 152% compared with the Fusarium control treatment. Populations of Fusarium and total bacteria were enumerated after 1, 3, 7, and 14 days of soil amendment. In amended soils, the population of Fusarium spp. gradually decreased while the population of total culturable bacteria increased. These results indicate that soil organic amendments, especially PPM, can decrease disease severity and promote plant growth, possibly by decreasing pathogen population and enhancing bacterial activity in the soil. © 2014 The American Phytopathological Society.This research was funded by Agriculture and Agri-Food Canada, by a JAEPredoc-CSIC grant to A. Borrego-Benjumea, and by projects INIA RTA 2006-00045 (Ministerio de Agricultura, Alimentación y Medio Ambiente, Spain) and P06-AGR-02313 (Consejería de Economía, Innovación y Ciencia, Junta de Andalucía).Peer Reviewe

Selection of potential antagonists against asparagus crown and root rot caused by Fusarium spp

4 pages; 1 figureCrown and root rot is one of the most important diseases of asparagus crop worldwide. Fusarium oxysporum f.sp. asparagi and F. proliferatum are the two species more frequently associated to this complex and their prevalence depends on the production area. The control of the disease on asparagus crop is difficult to achieve because its perennial condition and the long survival of the pathogen in the soil as chlamydospores or as mycelium in infected plant debris. Furthermore, Fusarium spp. are easily disseminated with asparagus propagation materials. Thus, control measures should aim at obtaining seedlings protection for longer than achieved with conventional pre-planting chemical treatments. The effectiveness of fungal antagonists on the control of diseases caused by soil borne fungi has been reported. The potential of Trichoderma spp. as a biological control agent against diseases caused by Fusarium spp. in tomato and asparagus has been studied . It has been suggested that microorganisms isolated from the root or rhizosphere of a specific crop may be better adapted to that crop and may provide better disease control than organisms originally isolated from other plant species. The objective of this work was the evaluation of the potential of fungal isolates from symptomless asparagus plants as biocontrol agents of Fusarium crown and root rot.Peer reviewe

Estrategias de control químico, físico y biológico para la reducción de la incidencia de Sclerotium cepivorum en el ajo morado de las pedroñeras

Resúmenes del XI Congreso de la Sociedad Española de Fitopatología.Peer reviewe

Ajo y cebolla huéspedes alternativos de Fusarium spp. patógenas de espárrago

Programa y Resúmenes del XV Congreso Nacional de la Sociedad Española de Fitopatología. P. 78. Vitoria, España, 2010.Sociedad Española de FitopatologíaPeer reviewe

Variabilidad en la respuesta a tebuconazol de diferentes aislados de Sclerotium cepivorum

Resúmenes del XI Congreso de la Sociedad Española de FitopatologíaPeer reviewe

Efecto del aporte de enmiendas orgánicas al suelo sobre las poblaciones de Fusarium spp. y sobre la podredumbre de rizomas y raíces de espárrago

Resúmenes del XIII Congreso de la Sociedad Española de FitopatologíaPeer reviewe