156 research outputs found
Comparative study of the pathogenicity of seabed isolates of Fusarium equiseti and the effect of the composition of the mineral salt medium and temperature on mycelia growth
The pathogenicity of seven strains of Fusarium equiseti isolated from seabed soil was evaluated on different host plants showing pre and post emergence damage. Radial growth of 27 strains was measured on culture media previously adjusted to different osmotic potentials with either KCl or NaCl (-1.50 to - 144.54 bars) at 15º, 25º and 35º C. Significant differences and interactive effects were observed in the response of mycelia to osmotic potential and temperature
The Interactive Effects of Temperature and Osmotic Potential on the Growth of Aquatic Isolates of Fusarium culmorum.
The mycelial growth of 10 Fusarium culmorum strains isolated
from water of the Andarax riverbed in the provinces of Granada
and Almeria in southeastern Spain was tested on potato-dextroseagar
adjusted to different osmotic potentials with either KCl or
NaCl (−1.50 to−144.54 bars) at 10◦C intervals ranging from15◦ to
35◦C. Fungal growth was determined by measuring colony diameter
after 4 d of incubation. Mycelial growth was maximal at 25◦C.
The quantity and capacity of mycelial growth of F. culmorum were
similar at 15 and 25◦C, with maximal growth occurring at −13.79
bars water potential and a lack of growth at 35◦C. The effect of
water potential was independent of salt composition. The general
growth pattern of Fusarium culmorum growth declined at potentials
below −13.79 bars. Fungal growth at 25◦C was always greater
than growth at 15◦C, at all of the water potentials tested. Significant
differences were observed in the response ofmycelia to water potential
and temperature as main and interactive effects. The number
of isolates that showed growth was increasingly inhibited as the
water potential dropped, but some growth was still observable at
−99.56 bars. These findings could indicate that F. culmorum strains
isolated from water have a physiological mechanism that permits
survival in environments with low water potential. Propagules of
Fusarium culmorum are transported long distances by river water,
which could explain the severity of diseases caused by F.culmorum
on cereal plants irrigated with river water and its interaction under
hydric stress ormoderate soil salinity. The observed differences
in growth magnitude and capacity could indicate that the biological
factors governing potential and actual growth are affected by
osmotic potential in different ways
Evaluación de la incidencia de enfermedades criptogámicas foliares en cereales de invierno y primavera en España. Periodo 1993-1996.
El trabajo presenta los resultados de evaluar las micosis foliares de los cereales durante tres campañas de cultivo consecutivas: 1993-94; 1994-95 y 1995-96. En la campaña 1993-1994 fueron evaluadas 154 variedades de trigo, triticale y cebada. Durante 1994-1995 se valoraron 145 variedades. En 1995-1996 fueron 161 las prospectadas y se ampliaron las observaciones a 9 cultivares de avena. Las variedades estuvieron cultivadas en ocho toponimias cerealícolas de España. Los resultados pusieron de manifiesto que las enfermedades más importantes fueron: Septoria tritici, Blumeria graminis f.sp.tritici, Puccinia recondita f.sp.tritici y Pyrenophora teres, en trigo blando o harinero(primavera e invierno),trigo duro y triticale. Muy discreta fue la presencia de la roya amarilla (Puccinia striiformis f.sp.tritici). En cebada (primavera y verano), Pyrenophora teres, Rhynchosporium secalis y Blumeria graminis f.sp.hordei fueron las especies fúngicas más importantes. Para las variedades de avena fue Puccinia coronata (roya coronada la enfermedad más frecuente. No pudieron establecerse diferencias entre variedades por su resistencia a alguno de los patógenos encontrados
Pathogenicity and fusaric acid production by fusarium proliferatum isolated from garlic in Spain
Fusarium proliferatum has been reported on garlic in the north west U.S.A., Spain and Serbia, causing as water-soaked tan lesions on cloves. Moreover, F. proliferatum is known to produce a range of toxins, including fumonisin B1, moniliformin, beauvericin, fusaproliferin and fusaric acid, which are implicated in pathogenesis. In this study six randomly selected F. proliferatum isolates from garlic were tested for pathogenicity and screened for fusaric acid production. Healthy seedlings of onion (Allium cepa), leek (A. porrum) and chives (A. schoenoprasum) and garlic clones (A. sativum) were inoculated. Onion seedlings and garlic clones were soaked in the conidial suspensions of each F. proliferatum isolate for 24 h and then planted in flats containing soil previously inoculated with the same isolate of F. proliferatum. Plants were maintained in a temperature and light-controlled greenhouse (12 h/12 h light/dark; 25/21°C). The root and bulb/clove rot disease symptoms were graded into five classes following the method of Stankovick et al. (2007). A disease severity index (DSI) was calculated as the mean of three plants of each species and four test replicates. Symptoms on onion and garlic plants were observed three weeks after inoculation. The overall effects of isolate, host and variety were analyzed. Effects were significant for all the studied isolates. The correlations between isolate pathogenicity and production of FA are also discussed
Stimulation of mycelial growth of pathogenic and seabed isolates of Fusarium oxysporum in presence of salts
Efecto de los contenidos de sal del medio en el crecimiento y viabilidad de aislados de F. oxysporu
The interactive effects of temperature and osmotic potential on the growth of marines isolates of Fusarium solani
The mycelial growth of 18 Fusarium solani strains isolated from sea beds of the south-eastern coast of Spain was tested on potato-dextrose agar adjusted to different osmotic potentials with either KCl or NACl (-1.50 to -144.54 bars) in 10ºC intervals ranging from 15 to 35ºC. Fungal growth was determined by measuring colony diameter after 4 days incubation. Mycelial growth was maximal at 25ºC. The quantity and frequency pattern of mycelial growth of F. solani differ significantly at 15 and 25ºC, with maximal occurring at the highest water potential tested (-1.50 bars); and at 35ºC, with a maximal mycelial growth at -13.79 bars. The effect of water potential was independent of salt composition. The general growth pattern of F. solani showed declining growth at potentials below -41.79 bars. Fungal growth at 35ºC was always higher than that growth at 15ºC, of all the water potentials tested. Significant differences observed in the response of mycelia to water potential and temperature as main and interactive effects. The viability of cultures was increasingly inhibited as the water potential dropped, but some growth was still observed at -99.56 bars. These findings could indicate that marine strains of F. solani have a physiological mechanism that permits survival in environments with low water potential. The observed differences in viability and the magnitude growth could indicate that the biological factors governing potential and actual growth are affected by osmotic potential in different ways
Species of Fusarium isolated from river and sea water of Southeastern Spain and pathogenicity on four plant species
Species of Fusarium were isolated from water samples collected from the Andarax River and coastal sea water of the Mediterranean in Granada and Almería provinces of southeastern Spain. In total, 18 water samples were analyzed from the Andarax River, and 10 species of Fusarium were isolated: Fusarium anthophilum, F. acuminatum, F. chlamydosporum, F. culmorum, F. equiseti, F. verticillioides, F. oxysporum, F. proliferatum, F. solani, and F. solani. When considering the samples by their origins, 77.8% of the river water samples yielded at least one species of Fusarium , with F. oxysporum comprising 72.2% of the total isolates. In the case of marine water, 45.5% of the samples yielded at least one species of Fusarium, with F. solani comprising 36.3% of the total isolates. The pathogenicity of 41 isolates representing nine of the species collected from river an sea water during the study ws evluated on barley, kohlrabe, melon, and tomato. Inoculation with F. acuminatum, F. chlamydosporum, F. culmorum, F. equiseti, F. verticillioides, F. oxysporum, F. proliferatum F. solani, and F. sambucinum resulted in pre-and post-emergence damping off. Pathogenicity of Fusarium isolates did not seem to be related to the origin of the isolates (sea water or fresh water). However, the presence of pathogenic species of Fusarium in river water flowing to the sea could indicate long-distance dispersal in natural water environment
Growth of Fusarium species as affected by temperature and osmotic potential (NaCl and KCl) interactions.
Myceliar growth of 90 Fusarium strains os F. acuminatum, F. chlamydosporum, F. culmorum, F. equiseti, F.verticillioides, F. oxysporum, F. proliferatum, F. solani an F. sambucinum isolated from fluvial channels and sea beds of the south-eastern coast of Spain was tested on potato-dextrose-agar adjusted to different matric potentials with either KCl or NaCl (from - 1.50 to - 144.54 bars)
First report of Fusarium proliferatum causing rot of garlic bulbs in Spain
In October of 2008, decayed garlic bulbs (Allium sativum cv. Blancomor de Vallelado) were received from a producer in Segovia, Spain. In November of 2009, similar symptoms were observed on stored bulbs (cultivars Blancomor de Vallelado and Garcua) from each of 30 municipalities in northwest Segovia and Valladolid. A minimum of one sample was collected from 12 localities. On the basis of morphological features and pathogenicity tests, the causal agent was identified as Fusarium proliferatum. F. proliferatum has been reported on garlic in the northwestern United States and Serbia. This is thought to be the first report of a Fusarium sp. in the section Liseola attacking garlic in Spain. The fungus seems to be well established on this host in Spai
Evaluación del poder patógeno de especies de Fusarium aisladas de aguas de cauces fluviales y fondos marinos de España sobre cuatro especies vegetales.
En este artículo se estudia la patogenicidad de las especies de Fusarium aisladas de muestras de fondos marinos del Mediterráneo y de aguas del cauce del río Andarax en las provincias de Granada y Almería (Sureste de España) sobre plántulas de cebada, colirrábano, melón y tomate. La evaluación del poder patógeno se hizo para 41 aislados de 9 especies de Fusarium aisladas de agus de mar y de río: F. acuminatum, F. chlamydosporum, F.culmorum, F. equiseti, F. verticillioides, F. oxysporum, F. proliferatum, F. sambucinum y F. solani. Todos los aislados de las diferentes especies mostraron patogenicidad tanto en preemergencia como en postemergencia de plántulas. No fue posible distiguir a los aislados según su procedencia: aguas marinas o de río
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