Download Homework 14

‫بسم هللا الرحمن الرحيم‬
Arya Widyawan
(428 121 714)
Lecture 14
PART I
1. Explain briefly about the adaptation of plant parasitic nematode.
Plant parasitic nematode makes an adaptation in two kinds; first is morphological and physiological
adaptation and second one is ecological adaptation. Morphological adaptation of plant parasitic
nematode may be observed in four different kinds; mouth spear, cuticle, muscle, and glands. While,
ecological adaptation of plant parasitic nematode is in growth and production of male.
The mouth spear
The most obvious adaptation to parasitism in phytoparasitic nematodes is the present of stylet.
There two kinds of stylet; stomatostylet and odontosylet. Stomato stylet presents in tylenchida
nematode while odoto sylet present in dorylaimida nematode.
Cuticle
The cuticle of plant parasitic nematode larvae contains regulary arranged vertical rods or striation in
the basal layer. These striations have a regular periodicity, ehoch tends to vary a little depending on
methods of fixation, but which is slightly greater transversely than longitudinally. In the larval cuticle
of Meloidogyne javanica, it averages about 20 nm. These regular spacing gives a resistant layer that
protect the larva from fluctuation in the environment and will lost within a week of larva’s entering
its host’s root.
Muscle
Partial atrophy of plant parasitic nematodes ‘ musculature is a most interesting example of
adaptation of endoparasitic mode of life. The part of the musculature which is necessary for the
establishment of a sound host-parasite relationship is retained, while that part which is associated
with movement of the whole nematodes is reabsorbed.
Gland
Esophageal gland
There are morphological and physiological changes that may be observed in the esophageal glands
of plant parasitic nematode. Morphological changes in these gland is that the irregular granule of
the preparasitic larvae which have a distinct outer membrane, are replaced in parasitic larvae by
smaller granules which have indistinct membrane and spackled appearance. Physiologically, the
esophageal gland of plant parasitic nematode is filled with mucopolysaccharide material.
Rectal gland
Rectal gland is a form of adaptation that may be observed in plant parasitic nematode. Rectal gland
will produce a gelatinous matrix. This matrix is a specialized adaptation to nematode’s parasitic
mode of life since it protects the large number of eggs.
1
growth
growth is a ecological adaptation of plant parasitic nematode. It has been showed in M. javanica,
when the nematode/plant weight ration is high, a stress is induced which results in a decrease in the
growth rate of the nematode. As this ratio decrease , the growth rate of nematode is increase.
Production of males
The increasing of number of male may be induced by the presence of other pathogens, increased
number of nematodes, nutritional deficiency of the host plant, reduced rate of photosynthesis in the
host and number of other factor that may induce the stress.
2. A. What is the advantages of producing a male in plant parasitic nematode population?
The advantages of producing a male in plant parasitic nematode population is that it is enable
population to leave the area under stress and also to the production of more fertilized eggs which
may stand a better chance of surviving
B. Is the following statement is true or false? Give a correct statement if the statement is
false
Among the plant parasitic nematodes those that show the most specialized adaptation to the
phytoparasitic mode of life are the semi endoparastic form.
False. The right answer is Among the plant parasitic nematodes those that show the most
specialized adaptation to the phytoparasitic mode of life are the sedentary endoparastic form.
3. What is the function of following enzyme
Enzyme
Lactate dehydrogenase
Isocotric dehydrogenase
Succinic dehydrogenase
Malic dehydrogenase
Transaminase
Phosphoglucomutase
Malate synthetase
Function
Catalyze pyruvic acid to the lacitic acid under an
aerobic condition
Catalyze the oxidative decarboxylation of
isocitric acid to a-ketoglutaric acid
Catalyze the conversion of succinic acid to
fumaric acid
Catalyze the conversion of malic acid to
oxalacetoc acid
Catalyze the intermolecular transfer of amino
goups
Catalyze the conversion of glucose 1 phosphate,
to glucose 6 phosphate
Catalyze the formation of malic acid by
combination of glyoxylic acid with acetyle Co A
4. Explain the two major concept concerning the mechanism of nematode feeding
Two major concept concerning themechanism of nematode feeding have been prposed.
Kostoff and Kendall (1903) proposed that the root knot nematode secured its nutrition by injecting a
secretion of its salivary glands into plant tissues. The secretion was tought to increase the
permeability of affected cells thus allowing the nematode to utilize host cell fluids that accumulated
in intercellular spaces.
2
Linford (1972) proposed that the root knot nematode obtains its food by penetrating cells with its
slender stylet and feeding directly from their suntances.
5. What are the characteristics of giant cell and syncytia?
Number of nuclei
Cytoplasm
Size of cell
Formation
Example of Nematode that
induce the structure
6.
Giant cell
Poly nuclei
Densely cytoplasm
big
Giant cell is formed from a
single cell
Meloidogyne spp.
Syncytia
Poly nuclei
Densely cytoplasm
Big
Syncytia is formed from many
cell which is dissolve together
Heterodera spp.
Explain briefly about the interaction of plant parasitic nematode and Verticillium wilt
Verticillium wilt is a typical vascular wilt disease and is similar to Fusarium wilt. It is often increased
by the presence of plant parasitic nematodes along with Verticillium species causing the disease.
Root lesion nematode (Pratylenchus spp.) are evidently the most important nematodes involved in
interaction with Verticllium wilt fungi. An important interrelationship exists between those two
pathogens in potatoes and peppermint. In both situation, damage is greater when nematodes and
fungus occur together.
7. Describe the interaction between nematode and bacterial wilt of alfalfa
Bacterial wilt of alfalfa, caused by Corynebacterium insidiosum, is increased by the stem nematode
Ditylenchus dipsaci. The effect may be observed in the green house and in the field. The basis for this
interaction may lie in transmission of the bacteria by D. dipsaci. Even varieties which have high
resistance to wilt become diseased in the presence of D. dipsaci . on the other hand, varieties with
nematode resistance remain relatively free from wilt when exposed to both pathogens.
8. Explain briefly about the mechanism of feeding by ectoparasitic nematode.
Mechanism of feeding by nematode consists of several step. Feeding activity is started by
exploration of feeding site. Plant parasitic nematode will use their sense organ (papillae) in order to
search their host. After finding an appropriate host, nematode start to perforate the cell wall by its
stylet. This activity is called perforation and may take 1 minute. After that, nematode will secrete a
digestive enzyme and toxin to do an extra corporal digestive activity. this activity takes 3 minute.
Following the extra corporal digestive activity, ingestion of nutrient by nematode takes place. This
activity takes 30 second. After finish, nematode will withdraw its stylet and find other host or
feeding site.
9. How many order of plant parasitic nematodes that able to transmit a virus? What are
they? What kind of virus that is transferred by them? Give some example of nematode
virus interaction!
There are five genera of plant parasitic nematode that able to transmit a virus. They are Longidorus,
Paralongidorus, Trichodorus, Paratrichodorus, and Xiphinema. The kind of virus that are transmitted
by those five genera are NEPO virus and TUBRA virus.
3
Genera
Longidorus
Paralongidorus
Xiphinema
Number of
Species that
able to transmit
virus
10
11
1
Trichodorus
Paratrichodorus
5
9
Kind of Virus
Example
Transmit
Polyhedral-Virus
(NEPO)
Arabis mosaic virus is transmitted by
Xiphinema diversicaudatum
Grape fan leaf virus is transmitted by X.
index
Raspberry ring spot virus (Scottish strain)
is transmitted by Longidorus elongatus
Tobacco rattle virus is transmitted by
Paratrichodorus anemone
Pea early browing virus is transmitted by
Trichodorus primitivus
Transmit
Tubular –Virus
(TUBRA)
10. How many technique can be used to do an enzymic analysis? What are those technique?
Which technique is used in the study of hostparasite interaction?
There are three kind of thecjique that can be use in ezymic analysis. Those three technique are
detection in exudates, detection in homogenates, and histochemical technique. The latter is used in
the study of host parasite interaction because reaction can be observed in living plant tissue under
natural conditions and localization of reactions permits conclusion about the particular cells
involved.
PART II
What is the new information that you get from this course?
The new information that is obtained from this course is about the control management , the
important of quarantine, induce resistance, and interaction of nematode with its host and other
organism such as bacteria, fungi and virus. Briefly a new information on control and nematode’s
interaction is described below
Control method
No
Method
Type of method
1
Thermotherapy
Physical control measure
2
Flooding
3
Cultivation
4
Bare fallowing
5
Crop rotation
6
Cultivation and root stock
7
Green manure and trap
cropping
8
Organic soil amendments*
9
Antagonistic organism
Biological control measure
4
10
Seed treatments
11
Transplant root dips
12
Fumigant nematicide
13
Non-fumigant nematicide
Chemical control measure
*: indirect biological control measure
The importance of quarantine in plant parasitic nematode control management
Quarantine is a very important point in nematode management strategies. Nematode management
strategies is defined as overall plan for nematode management. The plant include quarantine,
reduction of initial inoculums density, suppression of nematode reproduction, and restriction of
damage to current crop. Quarantine is defined as legislative control of the transport of plants or
plant parts to prevent the spread of pests or pathogens
(http://www.apsnet.org/education/IllustratedGlossary/default.htm)
Induce resistance
Induced resistance is a kind of resistance which is obtained because of the treatment. The treatment
may be by using an avirulent pathogen or chemical inducers of pathogenesis-related proteins such
as DL-b-amino-n-butyric acid (BABA). This kind of chemical inducer may be used to induce the
resistant of tomato against Meloidogyne javanica. Other example of application of induced
resistance has been observed in Japan. In order to control pine wilt disease which is caused by pine
wood nematode, Bursaphelenchus xylophilus, young pine trees in a nursery was inoculated with
avirulent B. xylophilus. This treatment has induced systemic resistance of trees against a subsequent
inoculation with virulent B. xylophilus. This induced resistance was considered a hopeful means for
developing a biological control for the disease.
Interaction between nematode and its host (Parasitism of nematode)
Table 1. Summary of Plant Parasitic Nematode Feeding Strategies
Feeding
Strategy
Example
Genera
Order
Infective Resistant Notes
Stage
Stage
Ectoparasite
Belonolaimus
Xiphenema
Trichodorus
Rhabditida
J2-adult
Dorylaimida J2-adult
Triplonchida J2-adult
SemiEndoparasites
Rotylenchulus
Tylenchulus
Rhabditida
Rhabditida
J4
J2
J4
J2
Migratory
Endoparasites
Pratylenchus
Radopholus
Rhabditida
Rhabditida
J2-adult
*
Sedentary
Endoparasites
Meloidogyne
Heterodera
Naccobus
Rhabditida
Rhabditida
Rhabditida
J2
J2
J2
Egg/cyst
Stem and Bulb
Nematodes
Bursaphelenchus Rhabditida
Ditylenchus
Rhabditida
J4
J4
J3
J4
Seed Gall
Nematodes
Anguina
Rhabditida
J2
J2
Foliar
Nematodes
Aphelenchoides
Rhabditida
J2-adult
Adult
Vector viruses
Vector viruses
J4 vectored by
insects
* eggs, all juvenile stages and adults can survive the winter, but not egg producing females.
5
Source: Lambert, K. and S. Bekal. 2002. Introduction to plant parasitic nematode.
http://www.apsnet.org/Education/IntroPlantPath/PathogenGroups/intronematodes/default.htm
Besides that, there is also some other new information that we get from reading some journal
related to nematode.
Group
Interaction
Title
Interaction of concurrent population of
Meloidogyne partityla and
Mesocriconema xenoplax on Pecan
Control
Effect of Fumigation on Rotylenchus
reniformis population density through
subsurface drip irrigation located every
other furrow
Control
Alternate row replacement is ineffective 1. Moving the placement of rows is
for cultural control of Meloidogyne
effective in suppressing early season
incognita in cotton
density of Rotylenchus reniformis and
increase yield in cotton by 30% one
year and 405 another year. In contrast
moving the placement of row is
ineffective to control M. incognita.
6
New information
1. M. partityla may suppress the
population of J2 of M. xenoplax. This
phenomena may be explain as a result
of competition between nematodenematode host-parasite interaction.
2. Interaction between two nematodes
does not always increase the severity
of disease. This is because of the
interaction between nematodes may
weaken each other (as observed in
this experiment)
1. When we want to apply a control
measure of nematode, we have to
consider several important things
such as what type of soil is, what kind
of irrigation method that we use, what
kind of control measure that we will
choose, and what the behavior of
nematode that we want to control.
2. Farmer who use Subsurface Drip
Irrigation (SDI)system face two
challenges in regards to manage R.
reniformis; the nematode is a very
deep parasite and SDI is not typically
deeper than 30 cm.
3. Peplant fumigation through drip
irrigation with 1,3 Dichloroprophene is
able to reduce the number of R.
reniformis, but only in the area closest
to the drip line
4. In order to achieve maximum result of
nematode control using a fumigation
on the SDI system, soil type becomes
the most important factor that must
be considered (Wang et al. 2004)
2.
Control
Management of lesion nematodes and
potato early dying with rotation crop
1.
2.
3.
The difference between this result
could be due to unknown
environmental condition.
Planting become an important factor
to control M. incognita by using a
alternate row replacement. Based on
the study, Perhaps movement of row
placement is more beneficial method
of nematode management in cotton
fields that are planted late.
This research has demonstrated that P.
penetrans may be reduce by one or
two years of rotation to nonhost or
antagonistic plant such as Saia oat,
Polynema marigold or R. hirta.
Polynema marigold has nematicidal
activity against root knot nematode
and root lesion nematode. Saia oat has
been shown to control lesion
nematodes. R. hirta reduce lesion
nematode density in pots.
Green manure cops (Saia oat,
Polynema marigold or R. hirta) are
not immediately practical. Saia oat is
not commercially available, while
polynema mari gold and R. hirta are
difficult to establish and do not
compete well with weeds.
Application of green manure should
consider several important factor
such as cultivar differences, location
effect or differences in soil microbial
ecology that may affect plant break
down product or soil nutrient level .
PART III
Control measure that may be applied in Indonesia
Control measure
flooding
application
In the beginning or before planting period. This
method appropriate at the rainy season
Ploughing In the early summer season
Farmer should crop several different crop in one
year period. This method effective to control
nematode that has specific host or restricted
host range
This method is very recommended. Resistant
and immune cultivar are available to control root
knot nematode (Meloidogyne spp.), some cyst
Cultivation
Crop rotation
Using a cultivar and rootstock which are immune
and resistant to plant parasitic nematode (if
available)
7
nematode (Globodera and Heterodera), some
shoot pest (Ditylenchus dipsaci), citrus nematode
Tylenchulus semipnetrans, some root lesion
nematode Pratylenchus and red ring nematode
(Rhadinaphelenchus cocophilus)
The method may decrease nematode number as
effectively as soil fumigation
Application could be done in the early season,
and in period of planting season. Beside for
nematode control, this method may increase the
crop’s yield
 Application is done in the early season. Some
example of antagonistic organism are
 Meloidogyne Vs. Arthrobotrys irregularis
Meloidogyne Vs.Paecilomyces lilacinus
Meloidogyne Vs. Bacillus penetrans
Meloidogyne Vs. Aspergillus niger
Meloidogyne Vs. Glomus manihotis
Meloidogyne Vs. Streptomyces
 it is very recommended to use a local strain as
antagonistic organism.
 Applying this method may be lessen early
nematode damage
 Using a nematicide as a means for controlling
nematode should be done by a professional
person.
 Seed moisture is a critical factor to success the
control method
 Application nematicide may be conducted if
the nematode has reached its economic injury
level (if the EIL has been calculated)
 If the IEL has not been calculated, management
decisions are often based on the presence of the
nematode and previous problems
Trap crop or green manure
Organic soil amendment
Antagonistic organism
Seed treatment
Nematicide
Some example of Economic Injury Level of Plant Parasitic Nematode
nematodes
Meloidogyne incognita
Economic Injury Level (EIL)
1250 or more nematode per plant for Dioscorea
rotundata
two eggs and larvae per 1 cc soil.
300 indv/100 cm3 soil
1
Heterodera schachtii 2
Heterodera glycine 3
Source:
1. http://www.apsnet.org/pd/PDFS/1983/PlantDisease67n07_814.PDF
2. http://info.ag.uidaho.edu/Resources/PDFs/CIS1072.pdf
3. http://nematode.unl.edu/extpubs/nemakan.htm
8