17 research outputs found
Detección de variabilidad macroscópica de Fusarium proliferatum mediante análisis de imagen
Fusarium proliferatum es un hongo fitopatógeno relevante por su capacidad de producir micotoxinas y del que existe poca información acerca de su variabilidad intraespecífica. Las características macroscópicas de sus colonias pueden ser utilizadas para caracterizar dicha variabilidad de una forma rápida y rutinaria. En este trabajo, se propone una metodología para poner a punto una técnica que permita diferenciar aislados de F. proliferatum en base a sus características morfológicas y cromáticas mediante el uso de técnicas de análisis de imagen. Se ha realizado la siembra de 27 aislados de F. proliferatum sobre placas Petri con medio de cultivo, incubadas a 25ºC, donde se realizaban capturas de imagen periódicas. Las imágenes fueron analizadas con el programa MATLAB con el uso de rutinas típicas y propias. Los resultados muestran que el análisis de imagen es una técnica idónea para la obtención de las tasa de crecimiento miceliar y parámetros cromáticos de una forma automática y rutinaria, lo que permite caracterizar los distintos aislados de F. proliferatum en base a estos parámetros
In vitro and field efficacy of three fungicides against Fusarium bulb rot of garlic
Efficacy of three fungicides against Fusarium bulb rot of garlic. Control of the garlic disease
Enfermedades y fisiopatías que afectan a la calidad del ajo en postcosecha
Las
enfermedades
y
fisiopatías
que
afectan
al
ajo
pueden
llegar
a
ocasionar
importantes
pérdidas
en
postcosecha,
de
vital
importancia
cuando
el
producto
se
destina
a
la
exportación
a
mercados
que
cada
día
son
más
exigentes.
En
2008,
distintos
agricultores
de
varios
municipios
de
Castilla
y
León
detectaron
bulbos
de
ajo
que
presentaban
síntomas
de
podredumbre
húmeda
durante
el
almacenamiento.
Posteriormente,
en
el
año
2009,
esta
misma
podredumbre
se
observó
también
en
las
provincias
de
Albacete
y
Cuenca
y
en
muestras
procedentes
de
Córdoba.
Hasta
la
fecha
se
ha
identificado
a
Fusarium
proliferatum
como
el
agente
causal
de
la
podredumbre
del
diente
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
Rhizoctonia solani as causative agent of damping off of Swiss chard in Europe
During September 2011, post-emergence damping off of Swiss chard (Beta vulgaris subsp. cicla L.) was observed
in a greenhouse in Villa del Prado (Spain). About 20% of the seedlings showed damping off symptoms. Lesions were
initially water soaked, dark brown necrosis of crown tissue, irregular in shape and sunken in appearance on large plants,
causing the infected seedlings to collapse and eventually die. Rhizoctonia solani was isolated consistently from symptomatic
plants. After morphological and molecular identification of the isolates, pathogenicity was tested by placing
agar plugs of four isolates adjacent to the stem at the three or four true leaf stage. In inoculated plants, brown crown
and stem necrosis occurred while control plants did not show disease symptoms. Pathogenicity using non-germinated
seeds was also tested. All four isolates produced extensive damping off when inoculated on non-germinated seeds. To
our knowledge, this is the first report of damping off of Swiss chard caused by R. solani in Europe
Detección de variablilidad macroscópica de Fusarium proliferatum mediante el análisis de imagen
Fusarium proliferatum es un hongo fitopatógeno relevante por su capacidad de producir micotoxinas y del que existe poca información acerca de su variablidad intraespecífica. Las características macoscópicas de sus colonias pueden ser utilizadas para caracterizar dicha variabilidad de una forma rápida y rutinaria. En este trabajo, se propone una metodología para poner a punto una técnica que permita diferenciar aislados de F. proliferatum en base a sus caracerísticas morfológicas y cormáticas mediante el uso de técnicas de análisis de imagen. Se ha realizado la siembra de 27 aislados de F. proliferatum sobre placas Petri con medicon medio de cultivo, incubadas a 25ºC, donde se realizaban capturas de imagen periódicas. Las imágenes fueron analizadas con el programa MATLAB con el uso de rutinas típicas y propias. Los resultados muestran que el análisis de imagen es una técnica idónea para la obtención de las tasa de crecimiento miceliar y parámetros cromáticos de una forma automática y rutinaria, lo que permite caracterizar los distintos aislados de F. proliferatum en base a estos parámetros
The effects of storage duration, temperature and cultivar on the severity of garlic clove rot caused by Fusarium proliferatum.
Diseases that affect garlic during storage can lead to severe economic losses for farmers worldwide. One causal agent of clove rot is Fusarium proliferatum. Here, the progress of clove rot caused by F. proliferatum and its dependence on different storage conditions and cultivar type were studied. The effect of temperature on mycelial
growth,
conidial
viability,
and
fungal
survival
during
garlic
commercial
storage
was
documented.
Samples
of
50
bulbs
from
a
randomized
field
trial
with
three
different
clonal
generations
for
purple
garlic
(F3,
F4
and
F5)
and
the
F4
clonal
generation
for
white
garlic
were
labeled
and
stored
for
two
months
(short-term
storage).
In
addition,
another
sample
of
the
F5
clonal
generation
of
purple
garlic
was
stored
for
6
months
after
harvest
(long-term
storage).
The
presence
of
the
pathogen
and
the
percentage
of
symptomatic
cloves
were
evaluated.
A
notable
difference
in
the
rot
severity
index
(RSI)
of
different
garlic
varieties
was
observed.
In
all
studied
cases,
clove
rot
increased
with
storage
time
at
20
◦
C,
and
the
white
garlic
variety
had
a
higher
index
of
rot
severity
after
two
months
of
storage.
Additionally,
there
were
clear
differences
between
the
growth
rates
of
F.
proliferatum
isolates.
Studies
conducted
on
the
temperature
responses
of
the
pathogen
propagules
showed
that
expo-
sure
for
at
least
20
min
at
50
◦
C
was
highly
effective
in
significantly
reducing
the
viability
of
fungal
conidia.
Pathogenicity
studies
showed
that
the
fungus
is
pathogenic
in
all
commercial
varieties.
However,
there
were
significant
differences
in
varietal
susceptibility
between
Chinese
and
white
garlic
type
cultivars
(81.84
±
16.44%
and
87.5
±
23.19%
symptomatic
cloves,
respectively)
and
purple
cultivars
(49.06
±
13.42%
symptomatic
cloves
Schizosaccharomyces selective differential media
This study discusses the optimisation of a selectiv
e and differential medium which would facilitate the
isolation of Schizosaccharomyces (a genus with a low incidence compared to other microorganisms) to select individuals from this genus for industrial purposes, especially in light of the recent approval of the use of yeasts from this genus in the wine industry by the International Organisation of Vine and Wine, or to detect the presence of such yeasts, for those many authors who consider them food spoilers. To this end, we studied various selective differential agents based on the main
thephysiological characteristics of this species, such as its high resistance to high concentrations of
sugar, sulfur dioxide, sorbic acid, benzoic acid, acetic acid or malo ethanolic fermentation. This selective medium is based on the resistance of the genus to the antibiotic actidione and its high resistance to inhibitory agents such as benzoic acid compared to possible microorganisms which can give rise to false positive results. Malic acid was used as a differential fact or due to the ability
of this genus to metabolise it to ethanol, which allows
detecting of the degradation of this compound. Lastly,
the medium was successfully used to isolate strains of
Schizosaccharomyces pombe from honey
Fusarium proliferatum isolated from garlic in Spain: Identification, toxigenic potential and pathogenicity on related Allium species
Fusarium proliferatum has been reported on garlic in the Northwest USA, Spain and Serbia, causing
water-soaked tan-colored lesions on cloves. In this work, Fusarium proliferatum was isolated from 300 symptomatic
garlic bulbs. Morphological identification of Fusarium was confirmed using species-specific PCR assays and EF-1α
sequencing. Confirmation of pathogenicity was conducted with eighteen isolates. Six randomly selected F. proliferatum
isolates from garlic were tested for specific pathogenicity and screened for fusaric acid production. Additionally,
pathogenicity of each F. proliferatum isolate was tested on healthy seedlings of onion (Allium cepa), leek (A.
porrum), scallions (A. fistulosum), chives (A. schoenoprasum) and garlic (A. sativum). A disease severity index (DSI)
was calculated as the mean severity on three plants of each species with four test replicates. Symptoms on onion
and garlic plants were observed three weeks after inoculation. All isolates tested produced symptoms on all varieties
inoculated. Inoculation of F. proliferatum isolates from diseased garlic onto other Allium species provided new
information on host range and pathogenicity. The results demonstrated differences in susceptibility with respect
to host species and cultivar. The F. proliferatum isolates tested all produced fusaric acid (FA); correlations between
FA production and isolate pathogenicity are discussed. Additionally, all isolates showed the presence of the FUM1
gene suggesting the ability of Spanish isolates to produce fumonisins
First report of Fusarium verticillioides causing stalk and root rot of sorghum in Spain
Podredumbre del tallo y la raíz del sorgo causada por Fusarium verticillioides en Españ