Nematode disease symptoms

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Nematode disease symptoms signs of nematodes

• Above ground symptoms
• a) Stunted growth
• b) Chlorosis and necrosis
• c) Incipient wilting
• d) Reduced plant stand
• e) Lesions on leaves
• f) Malformed floral parts, seed, leaves and
  stems

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Aphelenchoides
Anguina tritici in wheat
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Pratylenchus in American boxwood (chlorosis,
stunt)
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Turf-nematode, chlorosis
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Nematode in Corn, chlorosis and stunt
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Soybean cyst nematode chlorosis, stunt
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Nematode disease symptoms signs of nematodes

2) Below ground symptoms a) Stunted or
abbreviated roots b) Galls c) Lesions
d) Rotted e) Abbreviations of tubers f)
Hairy roots
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Nematode disease symptoms signs of nematodes

3) Signs of nematodes a) Cyst forms b)
Egg masses c) Female nematodes in roots
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????? ??
????? ??
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Secretory and excretory system

• Function removal of waste product
• (assumed to function in
  osmoregulation)
• 2. Forms
• 1) Tubular (Secernentea)
• - numerous cells
• - lateral excretory canals
• - terminal duct lined with cuticle
• 2) Glandular (Adenophorea)
• - single excretory gland cell
• - excretory duct not lined with cuticle

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Types of excretory system
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Nematode development

• ltThree stagesgt
• Embryogenesis(????)
• Post embryogenesis(????)
• Gametogenesis(?????)

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• Embryogenesis (???)
• ??? first stage juvnile(J1)

1) Determinate cleavage 2) Nondeterminated
cleavage 3) Meroblastic (???) 4) Holoblastic
(??)
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Egg laying
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Egg embryogenesis
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2. Post embryogenesis(????) J1 adult
Genital primordium (???? ????)
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Fourth molt of female
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Fourth molt of male
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3. Gametogenesis ??? ??(male and female)
1) Males 2) Females 3) Hermaphrodite(????) 4)
Intersex(??)
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Female intersex Morphologically appears as
female, but exhibit
secondary male characteristics,
e.g., spicules or bursa (not functional)
Ditylenchus triformis
Male intersex Morphologically appears as male,
but exhibit secondary female
characteristics, e.g.,
vulva or vagina (not functional)
Meloidogyne javanica
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Nematode life cycle
Molt1
J1
J2
Molt 2
embryogenesis
Egg

J3
Molt 3
Male or female
J4
Molt 4
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Four types of reproduction
1) Amphimixis 2) Parthenogenesis 3) Automixis
4) Pseudofertilization
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Amphimix ( Cross fertilization), ???? ??? ???
?? ? ??? ??? ??? ??? ?????? ??? ???? ???? ???
???? ???  Parthenogenesis , ????(????) ????
??? ??? ??? ???? ?? ?? ?? ???? ??? ??? ?????
???
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Automix ( Hermaphroditism, self
fertilization), ????? ????? ??? ??? ? ??? ???
??? ??? ?? ???? ????? ??? ??? ??? ???
Pseudofertilization (Pseudogamy) ??? ??? ?? ??
??? ??? ??? ??? ??? ????? ?? (??? ??? ??), ???
?? ???? ? ?? ??? ?? ? ???? ??. ??? ?? ???
??? ??? ???? ?? activator ??? ??.
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Nematoda (Phylum)

• Secernentea (??)
• Phasmid present
• Many celled excretory system
• Usuallly one testis
• Many eggs
• Stomatostylet
• Papilla on lips
• Plant parasitic, animal parasitic nematodes

• Adenophorea (??)
• 1) Phasmids absence
• 2) One-celled excretory
• system
• 3) Usually two testes
• 4) Few eggs
• 5) Odontostylet
• 6) Setae on lips
• 7) Marine nematodes,
• few plant, insect
• parasitic nematodes