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Journal ArticleDOI

89 % reduction of a potato cyst nematode population using biological control and rotation

01 Apr 2013-Agronomy for Sustainable Development (Springer-Verlag)-Vol. 33, Iss: 2, pp 425-431

TL;DR: The nematophagous fungus Paecilomyces sp.

AbstractA major issue of potato cultivation in temperate zones is the potato cyst nematode Globodera rostochiensis. Population density of G. rostochiensis is high in Mexican potato fields. Control currently consists of the inefficient application of high doses of chemical nematicides. We evaluated the population density of G. rostochiensis in potato production plots in central Veracruz, Mexico. Plots were treated with the biocontrol agent Paecilomyces sp. and rotation with two different leguminous crop plants, Pisum sativum and Vicia faba. A random block experimental design was used with four different treatments over two crop cycles: (1) biological control with crop rotation, (2) crop rotation only, (3) biological control applied to soil left in fallow, and (4) soil left in fallow only. We measured the number and content of cysts, and the number of J2 juveniles of G. rostochiensis in the soil. We then estimated the infestation level in soil and the multiplication rate (Pf/Pi). The number of free-living nematodes was also quantified. Results show that the highest mitigation of G. rostochiensis was observed for the biological control rotation, with 89.2 % reduction, and for the biological control fallow treatments with 84.4 % reduction. In rotation plots, infestation level decreased by 30.7 %. In the biological control rotation and biological control fallow treatments, the Pf/Pi was 0.1 and 0.15, respectively. The highest Pf/Pi of 0.93 was found in the fallow plots. The biological control agent did not significantly affect the free-living nematode populations. In this study, the nematophagous fungus Paecilomyces sp. was used for the first time to efficiently reduce the population of G. rostochiensis in two crop cycles.

Topics: Potato cyst nematode (57%), Globodera rostochiensis (57%), Crop rotation (54%), Population (53%)

Summary (1 min read)

1 Introduction

  • In the region of Cofre de Perote in Veracruz, Mexico, chemical control has produced poor results, and as a consequence of the potato monoculture, populations of this nematode have increased in some fields to more than 6,000 cysts kg soil−1 since initial detection in 1983 (Desgarennes et al. 2006).
  • For this reason, the implementation of integrated management that includes the control of this pest with agroecological methods such as biological control and crop rotation has been suggested (Lichtfouse et al. 2009).
  • Eight such composite samples were taken throughout the experiment (N0160), samples 1 to 4 taken during the first crop cycle (pea) with samples 5 to 8 taken in the second cycle (bean).

3 Results and discussion

  • An average of 203±75 cysts were found per 100 ml soil in the experiment plots at the beginning of the experiment.
  • The authors results from the rotation treatment plots concur with other studies that have shown populations decreasing by up to 40% after the second year of crop rotation in the absence of the host potato (Devine et al. 1999).

4 Conclusions

  • The authors recommend the initial sanitizing of the soils in highly infected areas prior to sowing new potato crops.
  • This strategy opens the possibility of rehabilitating and reactivating areas that are suitable for potato cultivation but are under quarantine at present.
  • At the same time, the lack of impact on free-living nematodes by the biological control agent can still permit the biological diversity necessary for nutrient cycling.
  • The first author is grateful for the support provided by CONACyT by provision of a grant (350758/ 238341) to carry out postgraduate study (Masters in Agriculture and Natural Resources) in the Universidad Autónoma del Estado de México.
  • Grateful thanks also go to the technician Magda Gómez for her help in the laboratory.

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89% reduction of a potato cyst nematode population
using biological control and rotation
Daniel López-Lima, Petra Sánchez-Nava, Gloria Carrión, Angel
Núñez-Sánchez
To cite this version:
Daniel López-Lima, Petra Sánchez-Nava, Gloria Carrión, Angel Núñez-Sánchez. 89% reduction of
a potato cyst nematode population using biological control and rotation. Agronomy for Sustainable
Development, Springer Verlag/EDP Sciences/INRA, 2013, 33 (2), pp.425-431. �10.1007/s13593-012-
0116-7�. �hal-01201359�

RESEARCH ARTICLE
89 % reduction of a potato cyst nematode population
using biological control and rotation
Daniel López-Lima & Petra Sánchez-Nava &
Gloria Carrión & Angel Enrique Núñez-Sánchez
Accepted: 6 September 2012 / Published online: 4 October 2012
#
INRA and Springer-Verlag, France 2012
Abstract A major issue of potato cultivation in temperate
zones is the potato cyst nematode Globodera rostochiensis.
Population density of G. rostochiensis is high in Mexican
potato fields. Control currently consists of the inefficient
application of high doses of chemical nematicides. We eval-
uated the population density of G. rostochiensis in potato
production plots in central Veracruz, Mexico. Plots were
treated with the biocontrol agent Paecilomyces sp. and ro-
tation with two different leguminous crop plants, Pisum
sativum and Vicia faba. A random block experimental de-
sign was used with four different treatments over two crop
cycles: (1) biological control with crop rotation, (2) crop
rotation only, (3) biological control applied to soil left in
fallow, and (4) soil left in fallow only. We measured the
number and content of cysts, and the number of J2 juveniles
of G. rostochiensis in the soil. We then estimated the infes-
tation level in soil and the multiplication rate (Pf/Pi). The
number of free-living n ematodes was also quantified.
Results show that the highest mitigation of G. rostochiensis
was observed for the biological control rotation, with
89.2 % reduction, and for the biological control fallow
treatments with 84.4 % reduction. In rotation plots, infesta-
tion level decreased by 30.7 %. In the biological control
rotation and biological contr ol fallow treatments, the Pf/Pi
was 0.1 and 0.15, respectively. The highest Pf/Pi of 0.93
was found in the fallow plots. The biological control agent
did not significantly affect the free-living nematode popula-
tions. In this study, the nematophagous fungus Paecilomy-
ces sp. was used for the first time to efficiently reduce the
population of G. rostochiensis in two crop cycles.
Keywords Potato cyst nematode
.
Golden nematode
.
Integrated management
.
Nematophagous fungi
1 Introduction
The potato cyst nematode Globodera rostochiensis (Woll.
1923) Skarbilovich, 1959 is considered to be a pest of great
economic significance to the cultivation of Solanum tuber-
osum worldwide (van Riel and Mulder 1998). It is estimated
to account for up to 83 % of losses in susceptible potato
crops in temperate zones (Cunha et al. 2004; Franco 1994).
Once established in the fields, it is very difficult to eliminate
due to its high multiplication rate (Desgarennes et al. 2006;
Turner 1996).
The main symptoms of infection are yellowing and hy-
dric stress (EPPO 2009). When juveniles in the infective
stage (J2) enter the root, they move through the cortex,
dissolving the cell walls. They subsequently become seden-
tary (Fig. 1a, b), forming feeding sites known as syncytia
(Sobczak and Golinowski 2011).
In Mexico, the potato cyst nematode is found in nine
states and is responsible for estimated annual potato produc-
tion losses of up to 70 % (Brodie 1998; Tovar et al. 2006). In
order to avoid the introduction, establishment, and dispersal
of G. rostochiensis to new cultivation areas, several phyto-
sanitary measures have been implemented. These prevent
farmers in infested sites from selling their product as seed;
however, the authorities have no control to stop movement
of the infected tubers, and this has allowed the dispersal of
D. López-Lima
:
P. Sánchez-Nava
Universidad Autónoma del Estado de México,
Unidad San Cayetano de Morelos,
50000, Toluca, Estado de México, México
G. Carrión (*)
Instituto de Ecología, A.C.,
Carretera Antigua a Coatepec 351,
91070, Xalapa, Veracruz, México
e-mail: gloria.carrion@inecol.edu.mx
A. E. Núñez-Sánchez
Facultad de Ciencias Agrícolas, Universidad Veracruzana,
Circuito Gonzalo Aguirre Beltrán s/n Col. Lomas del Estadio,
91090, Xalapa, Veracruz, México
Agron. Sustain. Dev. (2013) 33:425431
DOI 10.1007/s13593-012-0116-7

this nematode to new areas (Núñez-Sánchez et al. 2003;
SAGARPA 2002). Combat of the potato cyst nematode
involves the application of chemical nematicides of the
carbamate group (e.g., carbofuran, aldicarb, oxamyl); how-
ever, this nematicide application has not resulted in a re-
duced population of G. rostochiensis (Desgarennes et al.
2006). Moreover, due to the high mobility of these chem-
icals in the soil, there are many problems associated with
their use; these include their negative effect on beneficial
organisms (Haydock et al. 2006) and the fact that they can
contaminate groundwater, and because of their residual ef-
fect (1 20 days), they c an remain in the tuber until after
harvesting, representing a risk not only to the farmers who
apply these chemic als in the fie lds but a lso to the en d
consumers of the product (Mendes et al. 2005).
In the region of Cofre de Perote in Veracruz, Mexico,
chemical control has produced poor results, and as a conse-
quence of the potato monoculture, populations of this nem-
atode have increased in some fields to more than 6,000
cysts kg soil
1
since initial detection in 1983 (Desgarennes
et al. 2006). These values surpass the tolerance limit of 40
cysts kg soil
1
at which the nematode is considered to have
no effect on crop yield (EPPO 1996). For this reason, the
implementation of integrated management that includes the
control of this pest with agroecological methods such as
biological control and crop rotation has been suggested
(Lichtfouse et al. 2009).
Integrated management can favor the control of pests
through the combination of diverse control methods, since
this enhances the efficacy of each method on its own (Gurr
et al. 2004). This study evaluated, over two crop cycles, the
effect of the combination of two control strategies (biolog-
ical control and crop rotation) to reduce a population density
of G. rostochiensis. The fungus Paecilomyces sp. was
used as a biological control agent for the first time in
the experimental plots, and species identification w as
corroborated using genetic sequences. This fungus was
isolated in specimens of G. rostochiensis in the study
area, and its pathogenicity has been demonstrated in
vitro. Furthermore, this fungus is the subject of a patent
of use, which is currently in process (PCT-MX 2012-
000032). Pisum sativum and Vicia faba were used as
(non-host) rotation crops.
2 Materials and methods
2.1 Study area
The study was conducted in the community of Los Pesca-
dos, in the municipality of Perote, in Veracruz, Mexico (19°
3341 N, 97°0853 W, 2,980 m above sea level), over two
springsummer crop cycles (AprilOctober 2010 and 2011).
2.2 Experimental design
Twenty experimental plots of 50 m
2
were esta blished in
random blocks in a site with a high soil infestation of G.
rostochiensis and subject ed to fo ur tr eatm ents with five
replicates each: application of the biological control agent
with peas (P. sativum) sown as a rotation crop in the spring
summer cycle of 2010 and beans (V. faba) in the 2011 cycle;
the second treatment consisted of rotation only with no
application of biological control; the third treatment con-
sisted o f application of the biologic al control agent and
letting the soil lie fallow; the fourth treatmen t consisted of
letting the soil lie fallow only with no application of the
biological control. No tillage or weeding was carried out in
either of the two fallow treatments. Potato plants remaining
from the previous crop cycle were removed from all the
plots. The rotation and fallow plots were used as controls of
the cultivated and fallow plots, respectively. For those plots
sown with peas, the variety Canadiens e was used at a
density of 180 plants per plot, and for beans, the variety
Major was used at a density of 108 plants per plot. The
nematophagous fungus Paecilomyces sp. was used as the
biological control agent and was applied 10 days prior to
sowing and at the time of sowing, in each crop cycle, with
one further application made between the two crop cycles.
2.3 Inoculum preparation
The fungus was allowed to reproduce in a liquid medium
until reaching a concentration of 2×10
7
spores ml
1
. The
resulting suspension of spores was made up to 4 L with tap
water and applied directly to the soil with a manual spray
pump. Application dose was 4×10
10
spores per plot.
2.4 Population density of G. rostochiensis and free-living
nematodes
In each plot, composite soil samples were taken, comprising
five subsamples (each of 500 ml). Eight such composite
samples were taken throughout the experiment (N0 160),
samples 1 to 4 taken during the first crop cycle (pea) with
samples 5 to 8 taken in the second cycle (bean). In each
cycle, the first sample was taken 10 days prior to sowing;
the second was taken at the time of sowing and the rest at 60
Fig. 1 Globodera rostochiensis a females in potato roots, b eggs
within a cyst
426 D. López-Lima, et al.

and 120 days after sowing. All samples were taken follow-
ing a zigzag pattern throughout each plot.
The cysts were obtained using the Fenwick can (1940)
technique wh ile nematodes were extracted from the soil
using the sievec entrifuge technique (sJacob and van
Bezo oijen 1984) (100 ml of soil in each technique). To
determine the cyst content, the juveniles (J 2) and e ggs
within the cysts were quantified. The emerged J2 of G.
rostochiensis and free-living nematodes in the soil were
fixed and transferred to glycerin, following the Seinhorst
(1962) method.
G. rostochiensis was the only phytoparasitic nematode
considered since in previous studies, it was shown to be
the dominant species of potato crops in the study area
(Desgarennes et al. 2009). In each plot, the number of
cysts, their contents (eggs and J2 per cyst), and emerged
J2 juveniles extracted from the soil were quantified in order to
estimate the infestation level of G. rostochiensis:(numberof
juveniles and eggs 100 ml soil
1
)0 average cyst content×
number of cysts+J2 100 ml soil
1
. Initial population (Pi)
and final population (Pf) values of both G. rostochiensis and
free-living nematodes in all treatments were used to establish
the multiplication rate (Pf/Pi)0 final nematode population/ini-
tial nematode population.
2.5 Statistical analysis
Because the data obtained did not conform to assumptions
of normality (ShapiroWilk's test) or to equality of variance
(Levene's test), they were analyzed with the non-parametric
KruskalWallis (H, P 0.01) test and a multiple comparison
test to compare between all the treatments, as well as the
Wilcoxon T test (Tw, P 0.05) to compare the i nitial and
final populations in each treatment. All analyses w ere
carried out using the statistical STATISTICA 8.0 for
Windows.
3 Results and discussion
3.1 Population density of G. rostochiensis
An average of 203±75 cysts were found per 100 ml soil in
the experiment plots at the beginning of the experiment.
This is in broad agreement with the results obtained by
previous studies in the same community of Los Pescados,
where reports range from 1,656 to 6,200 cysts kg soil
1
(Desgarennes et al. 2006; Núñez-Sánchez et al. 2003). At
the end of the experiment, depending on treatment, the
number of cysts had either fallen or remained constant
(127±51), and no significant differences were found be-
tween the four treatments. Nonetheless, the average number
of cysts f ell over the course of the experiment in the
biological control fallow (Tw0 0.0, N0 10, P0 <0.05) and
fallow (Tw0 10, N0 10, P0 <0.05) treatments.
The average cyst content at the beginning of the experi-
ment was 12±6 eggs and J2 cyst
1
, with lower quantities of
eggs and J2 per cyst in the biological control fallow (7.1±
2.8) than in rotation (16.2±3.5). The variation found in the
content of the cysts in the crop fields at the beginning of the
experiment is partly due to the fact that, of the eggs
contained within cysts that had been in the soil for a longer
period of time, as little as 2 % may be viable while the cysts
that had formed in the previous crop cycle could p resent
50 % live eggs and juveniles (Desgarennes et al. 2006). For
this reason, using the number of cysts to estimate population
density of G. rostochiensis is inexact. Towards the end of
the experiment, both the eggs and J2 contents of the cysts
were reduced in the biological control rotation (1.7±1.5)
and b iological control fallow (2.2±1.6) treatments com-
pared to fallow (23.2±12.6) (H0 14.45, N0 20, P0 <0.01).
Moreover, the biological control rotation and biological
control fallow plots presented reduced quantities of eggs and
J2 per cyst over the course of the experiment (Tw0 0.0, N0 10,
P0 <0.05). In both of these biological control treatments, the
content of the cysts was reduced by 86 and 68 %, respectively.
This differs from the rotation plots, where the content of the
cysts was reduced by 31 % following two cultivation cycles.
In contrast, the content of the cysts in the fallow treatment
increased by 54 %. Our results from the rotation treatment
plots concur with other studies that have shown populations
decreasing by up to 40 % after the second year of crop rotation
in the absence of the host potato (Devine et al. 1999).
The average number of emerged J2 juveniles in the soil
samples in all treatments was low at the beginning of the
experiment (5±4 individuals per 100 ml soil). At the end of
the experiment, the lowest number of G. rostochiensis J2
juveniles was found in plots that had be en treat ed with the
nematophagous fungus (biological control rotation0 1±1;
biological contr ol fallow0 0.2±0.4). Of these, the number
in biological control fallow was significantly lower than that
of the rotation (6±4) and fallow (5±1) treatments (H0 14.7,
N0 20, P0 <0.01). In rotation treatment, the number of J2
remained low throughout the experiment, which could indi-
cate that the pea and bean crops utilized in the experiment
did not stimulate the emergence of G. rostochiensis.In
experiments carried out in the study area (unpublished data)
in potato crop without any control, we found higher than
500 J2 100 ml soil
1
. This is in broad agreement with the
results obtained by Brodie (1996) who reports 350 individ-
uals 100 ml soil
1
in the presence of the host potato. Fur-
thermore, in the treatments with biological control, we
found on revision of the cyst interiors that the eggs and J2
were damaged, bound together by fragments of mycelia. In
contrast, the eggs and J2 of the rotation and fallow treat-
ments were found to be healthy.
Eighty-nine percent reduction of potato cyst nematode population 427

Mean infestation level recorded in the treatments at the
beginning of t he experiment was 2,147±957 potentially
infective individuals per 100 ml soil. The effect of bione-
maticide application was seen in the biological control rota-
tion and biological contr ol fallow treatments from the fifth
sample onwards (beginning of the second year of rotation)
until the end of the experiment where infestation level was
very low (Table 1). In biological contr ol rotation, the infes-
tation le vel was reduced by 89.2 % (Tw0 0.0, N 0 10,
P0 <0.05). In contrast, in the treatment rotation, it dimin-
ished by only 30.7 %, which was a non-significant differ-
ence with respect to the initial value (Fig. 2a). Related
studies report that rotation with a non-host c rop (Avena
sativa) reduces the number of eggs 100 ml soil
1
by 30
40 %; however, subsequent sowing of a susceptible variety
of potato allows the population to recover (Brodie 1996). In
some studies, it has been demonstrated that rotation with
leguminous crops can achiev e a population reduction of G.
rostochiensis and Globodera pallida bybetween25and
30 % (Iriarte et al. 1999; Pacajes et al. 2002). From the first
crop cycle, pota to plants growing from tubers rem aining
from the previous crops in our experimental plots were
removed; however, we still had to remove potato plants
during the second cycle. This was due to the large quantity
of tubers that are left in the soil following harvest. For this
reason, with these potato plants growing in the fields sown
with non-host rotation crops, a certain amount of food was
still available for the potato cyst nematode, which resulted
in patches of high population density for the following crop
cycle. Reduction of infestation level in the biological control
fallow treatment was of 84.4 % (Tw0 0.0, N0 10, P0 <0.05)
relative to the initial values, while it was only 6.8 %, (Tw0
0.94, N0 10, P0 <0.34) in the fallow treatment (Fig. 2b).
These results are in agreement with studies conducted in
Bolivia, where leaving a soil fallow over one crop cycle
produced a reduction of 11 % in the infestation of Globodera
spp. (Pacajes et al. 2002). The use of soil fallow periods and
crop rotation as control methods for G. rostochiensis has not
been effective because this nematode can survive for up to
20 years in the absence of its host (Evans 1993), and its
population can still be viable after 10 years of cultivation of
non-host plants or of soil left in fallow (Esprella et al. 1994).
Similarly, the capacity of G. rostochiensis to survive in the soil
in the absence of a host crop should not be underestimated,
because it can reproduce in many wild host species that may
be present in the cultivated area (Sullivan et al. 2007).
3.2 G. rostochiensis multiplication rate
The lowest multiplication rates were found in the treatments
biological control rotation (0.1±0.09) and biological control
fallow (0.15±0.09) (H0 14.58, N0 20, P0 <0.01) (Table 1).
Although the Pf/Pi reduced by more than 80 % (Tw0 0.0,
N0 10, P0 <0.05) in both the biological control treatments, it
is more efficient to use the bionematicide along with crop
rotation using non-host crops for two consecutive years.
In studies using the fungus Pochonia chlamydosporia as
a biological control agent in potato cultivation, a Pf/Pi
of 8.9 was obtained (Tobin et al. 2008). At the end of
the experiment, a multiplication rate of 0.69±0.40 was
observed in the treatment rotatio n, s im i l ar to that found
by Iriarte et al. (1999)andPacajesetal.(2002)who
recorded a multiplication rate of 0.7 with rotation of
beans for 1 year. In our experiment, the highest Pf/Pi
was in treatment fallow (0.93±0.25), but no significant
differen ce s w er e o bs er v ed r el a ti ve to the ini ti al values
(Tw0 4, N0 10, P0 < 0.34). Pacajes et al. (2002 ) found a
multiplication rate of 0.89 after leaving soil in fallow for
1 year. For this reason, allowing soil to lie fallow without
carrying out some additional form of nematode control is not
an alternative in the short term for G. rostochiensis population
reduction. From these results, we consider that control of G.
rostochiensis should be conducted from the point of view of
integrated management and requires the use of biological
control with the rotation of non-host crops or with fallow
periods at the same time, in order to lower the population
density of the potato cyst nematode prior to the introduction of
a new potato crop.
Table 1 Populations of Globodera rostochiensis by treatment (eggs and J2±standard deviation 100 ml soil
1
)
Treatment initial population density
(Pi)
final population density
(Pf)
Pf/Pi % reduction
Biological control rotation 1,878±444a 181±130a 0.10±0.09a 89.2
Rotation 2,425±717a 1,486±483ab 0.69±0.4a 30.7
Biological control fallow 1,671±577a 240±134a 0.15±0.9a 84.4
Fallow 2,615±1602a 2,145±526b 0.93±0.2a 6.8
H 2.65 15.33 14.58
P 0.44 <0.01 <0.01
Different letters in each column denote significant differences between treatments indicated by a multiple comparisons test
H KruskalWallis test (P 0.01), Pf/Pi nematode multiplication rate
428 D. López-Lima, et al.

Citations
More filters

Journal ArticleDOI
TL;DR: Results suggest that S. sisymbriifolium has potential to significantly reduce G. pallida populations, and also that the cropping system (i.e. the sequence of non-host and host plants) may play a significant role in the efficacy of fungal biological control agents.
Abstract: The potato cyst nematode, Globodera pallida, is one of the most important pests of potato worldwide. Owing to regulatory considerations and potential environmental impact, control options for this nematode are becoming increasingly limited. Solanum sisymbriifolium and biological control agents offer viable alternative options for controlling G. pallida. Therefore, experiments were conducted to determine the effect of the nematode trap crop S. sisymbriifolium, alone or in combination with the biocontrol agents Trichoderma harzianum or Plectosphaerella cucumerina, on population decline of G. pallida. Experiments were conducted for three different ‘cropping systems’: potato (Solanum tuberosum), S. sisymbriifolium, or soil only (fallow), each followed by a potato crop. Soil was amended with P. cucumerina, T. harzianum or left unamended, and then infested with nematodes at a rate of five eggs g−1 of soil. After 16 weeks in the greenhouse, plants were removed and the soil containing cysts was refrigerated at 4°C for 8 weeks, and then planted to potato. Cysts of G. pallida were counted after an additional 16-week period. The Pf/Pi of G. pallida was significantly reduced by 99% in potato following S. sisymbriifolium compared to both the potato-following-fallow and the potato-following-potato treatments. Amendment of soil with T. harzianum significantly reduced Pf/Pi of G. pallida by 42–47% in the potato-following-potato but not in either the potato-after-fallow nor in the potato-after-S. sisymbriifolium cycles which supports evidence that the plant species may play a role in the biocontrol activity of this fungus. Addition of the fungus P. cucumerina resulted in a 64% decrease in Pf/Pi in the potato-following-fallow in one experiment, and an 88% decrease in Pf/Pi in potato-following-potato but the decrease in Pf/Pi was not consistent over all experiments. However, both biocontrol fungi resulted in lower numbers of progeny cysts after an initial 16-week incubation with potato. To look at the effect of varied population density of the nematode on efficacy of S. sisymbriifolium to reduce G. pallida populations, potato, S. sisymbriifolium, or barley were planted into soil infested with G. pallida at rates of 5, 20 or 40 eggs g−1 soil applied as cysts (20, 80 or 160 cysts pot−1). After 16 weeks, numbers of cysts produced in each treatment were determined for each infestation rate. No new cysts were recovered from either S. sisymbriifolium or barley treatments, confirming that neither plant is a host for G. pallida. High numbers of cysts were recovered with potato. Soil from each treatment (containing original cysts and newly-formed cysts when present) were then planted with potato. After an additional 16 weeks, few cysts were found in the potato-after- S. sisymbriifolium treatments regardless of initial infestation rate. When potato followed barley, numbers of cysts were similar to those found after a single cycle of potato, indicating that the barley crop had no effect on the survival of initial inoculum. Overall, these results suggest that S. sisymbriifolium has potential to significantly reduce G. pallida populations, and also that the cropping system (i.e. the sequence of non-host and host plants) may play a significant role in the efficacy of fungal biological control agents.

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Journal ArticleDOI
TL;DR: It is concluded that actinomycetes St. rochei SM3 trigger the ET-mediated defence pathway in chickpea and activates the phenylpropanoid pathway for alleviating the stresses caused by Sc.
Abstract: Understanding on actinomycetes-mediated stress tolerance in plants is very limited. This study demonstrated for the first time some stress tolerance mechanisms in chickpea via mediation of an actinomycetes strain Streptomyces rochei SM3. Here, we used the strain SM3 for treating chickpea seeds and plants raised from such seeds were challenged with Sclerotinia sclerotiorum and NaCl. Chickpea mortality due to Sc. sclerotiorum infection was suppressed by nearly 48%, and biomass accumulation was increased by nearly 20% in the salt-stressed condition in SM3-treated plants compared to non-treated plants. Physiological responses in chickpea under the challenging conditions showed that phenylalanine ammonia lyase activities increased in SM3-treated plants. This is followed by accumulation of higher concentrations of phenolics that led to enhanced lignifications in SM3-treated plants compared to non-SM3-treated plants challenged with the same stresses. Antioxidant activities, as assessed through catalase activities and proline accumulation, also increased in SM3-treated plants challenged with both the stresses compared to non-SM3-treated plants. Investigation at genetic level further showed that the strain SM3 triggered the ethylene (ET) responsive ERF transcription factor (CaTF2) under the challenged conditions. Thus, from this study, we conclude that actinomycetes St. rochei SM3 trigger the ET-mediated defence pathway in chickpea and activates the phenylpropanoid pathway for alleviating the stresses caused by Sc. sclerotiorum and salt in chickpea.

23 citations


Journal ArticleDOI
TL;DR: This study is the first to report that Azospirillum inoculation of potato microclones not only improves the quality of planting material produced in vitro but also significantly increases minituber yield through enhancing plant adaptive capacity in the field.
Abstract: Microclonal propagation in vitro is being actively used in the production of healthy planting material of food and ornamental plants. However, it needs further improvement to increase the growth rates of microclones in vitro and enhance regenerant survivability ex vitro. A promising approach to this end could be inoculating in vitro-micropropagated plants with plant growth-promoting rhizobacteria, specifically Azospirillum. However, the influence of Azospirillum inoculation on microclone behavior throughout the production process, including plant adaptation ex vitro and food crop productivity, has been underinvestigated. In this study, in vitro-growing potato (Solanum tuberosum L.) microclones were inoculated with Azospirillum brasilense strain Sp245. The microclones were then grown on in soil in the greenhouse and field, with the experiment lasting for 120 days. Root-associated bacteria were identified immunochemically, and the mitotic index of root meristematic cells was determined by a cytological method. The plant morphological parameters determined were shoot length, number of nodes per shoot, number of roots per plant, maximal root length, leaf area, percentage of surviving plants in the soil, and tuber yield and weight. Our results show that bacterial inoculation of potato microclones in vitro enhances plant adaptive capacity ex vitro and increases minituber yield. The percent survival index of field-grown inoculated plants was 1.5-fold greater than that of uninoculated plants. The overall tuber weight per plant was more than 30 % greater in the inoculated plants than it was in the control ones. For all cultivars on average, tuber yield per square meter increased by more than 45 % as a result of inoculation in vitro. This study is the first to report that Azospirillum inoculation of potato microclones not only improves the quality of planting material produced in vitro but also significantly increases minituber yield through enhancing plant adaptive capacity in the field.

19 citations


Journal ArticleDOI
TL;DR: This study is the first to report on the ability of G. pannorum and P. carneus to increase the available phosphorus in the soil, suggesting that these fungal species may have potential uses in agricultural soils with insoluble phosphorus.
Abstract: We evaluated the nematicidal potential and phosphate solubilization ability of the fungal species Geomyces pannorum and Paecilomyces carneus, which are associated with the potato cyst nematode Globodera rostochiensis. In a broth medium containing calcium phosphate, the two fungi solubilized between 67%-96% of the insoluble phosphorus that was present in the medium, and in a broth medium containing iron phosphate, the phosphorus that was solubilized by the two fungi ranged between 2%-13%. In a greenhouse experiment, G. pannorum and P. carneus were applied to soil that was naturally infested with G. rostochiensis and planted with Avena sativa. The fungi increased the available phosphorus in the soil by more than 30%, and Paecilomyces carneus also reduced the nematode population by 71%. This study is the first to report on the ability of G. pannorum and P. carneus to increase the available phosphorus in the soil, suggesting that these fungal species may have potential uses in agricultural soils with insoluble phosphorus. Moreover, this study provides a new alternative that contributes to the sustainable management of crops with bio-agents that have dual activity; they increase the available phosphorus in the soil and mitigate plant parasitic nematodes.

16 citations


Cites background from "89 % reduction of a potato cyst nem..."

  • ...In fact, Paecilomyces carneus nematicidal potential has already been shown in the field against G. rostochiensis (Lopez-Lima et al., 2013)....

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Journal ArticleDOI
10 Dec 2020
TL;DR: Paecilomyces is a cosmopolitan fungus that is mainly known for its nematophagous capacity, but it has also been reported as an insect parasite and biological control agent of several fungi and phytopathogenic bacteria through different mechanisms of action.
Abstract: Incorporating beneficial microorganisms in crop production is the most promising strategy for maintaining agricultural productivity and reducing the use of inorganic fertilizers, herbicides, and pesticides. Numerous microorganisms have been described in the literature as biological control agents for pests and diseases, although some have not yet been commercialised due to their lack of viability or efficacy in different crops. Paecilomyces is a cosmopolitan fungus that is mainly known for its nematophagous capacity, but it has also been reported as an insect parasite and biological control agent of several fungi and phytopathogenic bacteria through different mechanisms of action. In addition, species of this genus have recently been described as biostimulants of plant growth and crop yield. This review includes all the information on the genus Paecilomyces as a biological control agent for pests and diseases. Its growth rate and high spore production rate in numerous substrates ensures the production of viable, affordable, and efficient commercial formulations for agricultural use.

11 citations


References
More filters

Journal ArticleDOI
TL;DR: The most recent colonizer–persister allocation and the application of this scaling in the Maturity Index, cp-triangles, MI(2–5) and PPI/MI-ratio is presented and the life strategy approach and trophic group classification are proposed to integrate to obtain a better understanding of nematode biodiversity and soil functioning.
Abstract: Nematodes are the most abundant metazoa. Their food specificity, the high number of species and high abundance in every habitat where decomposition takes place indicates that the structure of the nematode community has a high information content. Since nematodes respond rapidly to new resources, and the nematode fauna can be efficiently analyzed, the structure of the nematode community offers an instrument to assess (changes in) the conditions of soils. A functional grouping of nematodes is generally synonymous with allocation into feeding groups. However, soil quality assessment indices based on the presence of all feeding groups still provide insufficient information regarding the functioning of soil ecosystems and their threats. An alternative concept of functional groups is based on the life history of nematodes. In this paper we present the most recent colonizer–persister allocation and the application of this scaling in the Maturity Index, cp-triangles, MI(2–5) and PPI/MI-ratio. We propose to integrate the life strategy approach and trophic group classification to obtain a better understanding of nematode biodiversity and soil functioning. Attention is given to competitive exclusion and coexistence and we summarize present concepts regarding succession and degradation.

850 citations


"89 % reduction of a potato cyst nem..." refers background in this paper

  • ...The free-living nematodes play an important role in the agroecosystem through their participation in the decomposition of organic material and mineralization of nutrients in the soil as well as through their function as regulators of populations of fungi, bacteria, and insects (Bongers and Bongers 1998)....

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  • ...…nematodes play an important role in the agroecosystem through their participation in the decomposition of organic material and mineralization of nutrients in the soil as well as through their function as regulators of populations of fungi, bacteria, and insects (Bongers and Bongers 1998)....

    [...]


Journal ArticleDOI
TL;DR: A method of recovering cysts from soils of not more than 10% water content and the yield was found to contain a slightly lower percentage of full cysts than that obtained by dry flotation but this drop was not considered sufficiently great to justify the drying of soil in large quantities.
Abstract: A method of recovering cysts from soils of not more than 10% water content is described. The method is continuous and the yield from it is only slightly lower than that from the dry flotation of soil. The yield was found to contain a slightly lower percentage of full cysts than that obtained by dry flotation but this drop was not considered sufficiently great to justify the drying of soil in large quantities. Quantities of soil in the neighbourhood of 1 cwt. can be handled continuously in a matter of two hours.

254 citations


BookDOI
01 Jan 2011
TL;DR: This chapter discusses the role of Arabidopsis as a tool for the study of plant-nematode interactions, and next generation sequencing technology to study plant responses to nematode infection.
Abstract: Part I - Introductory Chapters. 1. Introduction to Plant-parasitic Nematodes Modes of Parasitism. 1.1. Introduction to Nematodes. 1.2. Evolution of Plant Parasitism. 1.3. Hatching. 1.4. Attraction to Plants. 1.5. Penetration and Feeding. 1.6. Moulting. 1.7. Reproduction. 1.8. Survival. 1.9. Conclusions. 2. Current nematode threats to world agriculture. 2.1 Key nematodes threatening major agricultural crops of importance worldwide. 2.2 Quarantine nematodes of global importance. 2.3 Key nematodes on food staples for food security in developing countries. 3. Phylogeny and evolution of nematodes. 3.1 Introduction. 3.2 Backbone of nematode phylogeny. 3.3 Phylogeny of Tylenchomorpha. 3.4 Tylenchomorpha - top end plant parasites. 3.5 Concluding remarks. 4. Cyst nematodes and syncytia. 4.1 Introduction. 4.2 Root invasion and selection of the initial syncytial cell. 4.3 Syncytium development. 4.4 Syncytium ultrastructure. 4.5 Defence responses. 4.6 Concluding remarks. 5. Root-knot nematodes and giant cells. 5.1 Introduction. 5.2 Root invasion and migration. 5.3 Giant cell formation and function. 5.4 Giant cell induction - a deliberate controlled event. 5.5 Host resistance to root-knot nematodes. 5.6 Concluding remarks. Part II - Resources for functional analysis of plant-nematode interactions. 6. Genome analysis of plant parasitic nematodes. 6.1 Introduction. 6.2 Sequencing strategies. 6.3 Genome organization. 6.4 Plant parasitism. 6.5 Gene family and pathway conservation and diversification among plant parasitic and free-living nematodes. 6.6 Tools for functional genomics and genetics. 6.7 Future prospects sequencing of parasitic nematode genomes. 7. Transcriptomes of plant-parasitic nematodes. 7.1 Introduction. 7.2 Intra-specific transcriptomics has proven a powerful approach to identify parasitism-related genes. 7.3 Expressed sequence tags, the most versatile source of molecular data for plant parasitic nematodes. 7.4 Web-Based Access to Plant Parasitic Nematode EST data and tools to support analysis. 7.5 Functional and structural characterization of ESTs: understanding the molecular basis of parasitism. 7.6 Pan-phylum transcriptomics: an approach that reveals broadly conserved and taxonomically restricted molecular features in Nematoda. 7.7 The future of plant parasitic nematode transcriptomics. 8. Arabidopsis as a tool for the study of plant-nematode interactions. 8.1. Why Arabidopsis was the best choice for molecular approaches to plant-nematode interactions: a historical perspective. 8.2. Findings that were possible because of Arabidopsis. 8.3. High expectations that never quite made true. 8.4. When it would be better to use other model systems. 8.5. Future prospects: will Arabidopsis still be the best or only choice?. 9. Transcriptomic and proteomic analysis of the plant response to nematode infection. 9.1. Parasitic nematode interaction with plants. 9.2. A historical view of methods used to study transcriptional changes during plant-nematode interactions. 9.3. Microarray analysis of nematode-infected root tissues. 9.4. Next generation sequencing technology to study plant responses to nematode infection. 9.5. Proteomic analysis of the plant response to nematode infection. 9.6. Conclusions. 10. C. elegans as a resource for studies on plant parasitic nematodes. 10.2. C. elegans as a model nematode. 10.3. Application of RNAi in C. elegans and parasitic nematodes. 10.4. General conclusion and future perspectives. 11. Parallels between plant and animal parasitic nematodes. 11.1 Introduction. 11.2 Morphology. 11.3 Life Histories. 11.4. Neuronal Signalling Systems. 11.5. Endosymbionts. 11.6. Host-Parasite Interactions. 11.7. Concluding Remarks. Part III - Molecular genetics and cell biology of plant-nematode interactions. 12. Degradation of the plant cell wall by nematodes. 12.1 Introduction. 12.2 Enzymatic degradation of plant cell walls. 12.3 Non-enzymatic modification of plant cell walls. 12.4 Degradation of fungal cell walls. 12.5 Evolutionary aspects of cell wall modifying proteins. 12.6 Concluding remarks. 13. Suppression of plant defences by nematodes. 13.1 Plant parasitic nematodes as biotrophic pathogens. 13.2 Protection of the feeding site (biotrophy). 13.3 Protection of the nematode. 13.4 Conclusions and future prospects. 14. Other nematode effectors and evolutionary constraints. 14.1 A wide range of effectors are secreted during parasitism. 14.2 Signalling and protection at the plant-nematode interface. 14.3 Stylet secretions are major parasitism effectors. 14.4 Nematode effectors can trigger plant resistance. 14.5 Evolution of nematode effectors. 15. Disease resistance-genes and defense responses during incompatible interactions. 15.1 Introduction. 15.2 Nematode resistance genes. 15.3 Defense responses during incompatible interactions. 15.4 Resistance mechanisms. 15.5 Concluding remarks. 16. The role of plant hormones in nematode feeding cell formation. 16.1 Introduction. 16.2 Phytohormone-associated gene expression profiles in feeding cell formation. 16.3 Auxin. 16.4 Ethylene. 16.5 Cytokinin. 16.6. Peptide hormones. 16.7. Perspectives. 17. Unravelling the plant cell cycle in nematode induced feeding sites. 17.1 Introduction. 17.2. Transcriptional activity and transcript levels of cell cycle genes in nematode feeding sites. 17.3 In situ profiling of cell cycle genes in uninfected Arabidopsis: a useful source of information for nematode feeding sites. 17.4 DNA synthesis and the endocycle in the multinucleate giant cells and syncytia. 17.5 Cell Cycle inhibitors influence DNA synthesis and mitosis in feeding cells. 17.6 Concluding remarks. 18. The plant cytoskeleton remodelling in nematode induced feeding sites. 18.1. Introduction. 18.2. Actin and tubulin genes are highly expressed in nematode feeding sites. 18.3. Cytoskeleton rearrangements in nematode feeding sites. 18.4 The effects of cytoskeleton-disrupting drugs on nematode feeding sites. 18.5. Cytoskeleton interacting proteins and their putative role in feeding site development. 18.6. Closing remarks. 19. Cell wall modifications induced by nematodes. 19.1 Introduction. 19.2 Ultrastructure of feeding site wall in susceptible interactions. 19.3 Expression of genes involved in cell wall extension and remodeling. 19.4 Expression of genes involved in cell wall degradation in NFS. 19.5 Expression of genes involved in cell wall biosynthesis in NFS. 19.6 Ultrastructure of feeding site wall in resistant interactions. 19.7 Nematode development and cell wall modifications in plants with silenced expression of cell wall-related genes. 19.8 Summary. 20. Water and nutrient transport in nematode feeding sites.- 20.1 Nematodes as obligate parasites depend on plant water and solute supply.- 20.2 Water transport.- 20.3 Solute supply of nematode-induced feeding structures.- 20.4 Other plant-nematode interactions.- 20.5 Nematode feeding.- 20.6 Nutrient cycling and limited nutrient supply.- 20.7 Conclusions.- Part IV - Applied aspects of molecular plant nematology: exploiting genomics for practical outputs. 21. Molecular tools for diagnostics. 21.1 Introduction. 21.2 Markers for PCR diagnostics. 21.3 Other diagnostic methods. 21.4 Soil PCR. 21.5. Validation and troubleshooting. 21.6. Future research and perspectives. 21.7. Conclusions. 22. Breeding for nematode resistance: use of genomic information. 22.1 Introduction. 22.2: Mapped nematode resistance genes and QTLs. 22.3: Molecular marker-assisted breeding for resistance to nematodes. 22.4: Genes underlying resistance to nematodes. 22.5: Breeding for durable resistance to nematodes. 22.6 Conclusions. 23. Biological Control of Plant-Parasitic Nematodes: Towards Understanding Field Variation Through Molecular Mechanisms. 23.1 Introduction. 23.2 Ecological Context. 23.3 Molecular approaches for assessing field biodiversity. 23.4 Towards understanding field variation through molecular mechanisms: three models. 23.5 Future developments. 24. Nematode resistant GM crops in industrialised and developing countries. 24.1 Introduction. 24.2 Manipulation of Plant Resistance. 24.3 Development of biotechnological solutions to nematode control. 24.4 Progress towards transgenic resistance in crop plants. 24.5 Future developments. 24.6 Prospects for implementation of biotechnological control.

227 citations


Journal ArticleDOI
TL;DR: Killing nematodes by means of a hot solution of 0.5% acetic acid in water keeps they in a better condition than heating them in a drop of water.
Abstract: Killing nematodes by means of a hot solution of 0.5% acetic acid in water keeps them in a better condition than heating them in a drop of water. A pipette for heating and transferring the acetic acid solution and a small dish for the evaporation of alcohol from an alcohol-glycerin mixture are described.

208 citations


"89 % reduction of a potato cyst nem..." refers methods in this paper

  • ...The emerged J2 of G. rostochiensis and free-living nematodes in the soil were fixed and transferred to glycerin, following the Seinhorst (1962) method....

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Journal ArticleDOI
Abstract: Sustainability rests on the principle that we must meet the needs of the present without compromising the ability of future generations to meet their own needs. Starving people in poor nations, obesity in rich nations, increasing food prices, on-going climate changes, increasing fuel and transportation costs, flaws of the global market, worldwide pesticide pollution, pest adaptation and resistance, loss of soil fertility and organic carbon, soil erosion, decreasing biodiversity, desertification, and so on. Despite unprecedented advances in sciences allowing us to visit planets and disclose subatomic particles, serious terrestrial issues about food show clearly that conventional agriculture is no longer suited to feeding humans and preserving ecosystems. Sustainable agriculture is an alternative for solving fundamental and applied issues related to food production in an ecological way (Lal (2008) Agron. Sustain. Dev. 28, 57–64.). While conventional agriculture is driven almost solely by productivity and profit, sustainable agriculture integrates biological, chemical, physical, ecological, economic and social sciences in a comprehensive way to develop new farming practices that are safe and do not degrade our environment. To address current agronomical issues and to promote worldwide discussions and cooperation we implemented sharp changes at the journal Agronomy for Sustainable Development from 2003 to 2006. Here we report (1) the results of the renovation of the journal and (2) a short overview of current concepts of agronomical research for sustainable agriculture. Considered for a long time as a soft, side science, agronomy is rising fast as a central science because current issues are about food, and humans eat food. This report is the introductory article of the book Sustainable Agriculture, volume 1, published by EDP Sciences and Springer (Lichtfouse et al. (2009) Sustainable Agriculture, Vol. 1, Springer, EDP Sciences, in press).

194 citations


"89 % reduction of a potato cyst nem..." refers background in this paper

  • ...For this reason, the implementation of integrated management that includes the control of this pest with agroecological methods such as biological control and crop rotation has been suggested (Lichtfouse et al. 2009)....

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Frequently Asked Questions (2)
Q1. What contributions have the authors mentioned in the paper "89 % reduction of a potato cyst nematode population using biological control and rotation" ?

In this study, the nematophagous fungus Paecilomyces sp. was used for the first time to efficiently reduce the population of G. rostochiensis in two crop cycles. 

This strategy opens the possibility of rehabilitating and reactivating areas that are suitable for potato cultivation but are under quarantine at present. These practices can be relatively easily incorporated by producers into the system of potato production that exists at present.