The document provides a detailed overview of nematodes, including their classification, life cycle, feeding habits, and examples of various types such as migratory ectoparasites and endoparasites. It outlines symptoms caused by nematode infestations on plants, including discoloration, distortion, galls, and lesions. Key examples highlight the impact of different nematode species on various crops and the associated morphological symptoms.

1. Presented By:
MOHD SHARIQ
2014BTM15

2. Nematodes (from Greek nema
which means ‘thread’ and Latin
oid which means ‘like’) are
ubiquitous, thread like worm,
bilaterally symmetrical,
vermiform, unsegmented,
pseudocoelomate
animal.

3. 1. Invertebrate
2. Pseudocoelomate
3. Round in cross section
4. Vermiform
5. Heterotrophic
6. Non-segmented
7. Triploblastic
8. Motile

6.  Spend thier entire life cycle in soil, all life cycle stages,
including eggs in soil.
 Only stylet is inserted into roots, body remains outside.
 A vast majority of ectoparasites feed on root hairs and
epidermal cells.
Migratory ectoparasites
 Feed outside of root, move cell-to-cell but do not enter
inside the root.
 Remain vermiform, eggs are scattered in soil.
Examples:
Sting nematode - Belonolaimus
Dagger nematode - Xiphinema
Needle nematode - Longidorus
Stubby root nematode –Trichodorus,
Paratrichodorus

8.  Feed at a particular site for long time.
 Very sluggish in movement.
 May secrete an adhesive plug to fix their stylet at a particular
feeding point.
Examples:
Sheath nematode - Hemicycliophora arenaria
Sessile nematode - Cacopaurus pestis

10.  The anterior portion of the body of nematode is inserted inside
the plant tissue and the posterior part extents free into the soil.
Migratory semi-endoparasites
 Remain vermiform
 Do not establish a permanent feeding site in plant tissues and
move from one site to another frequently.
 Eggs are not deposited in masses.
Examples:
Spiral nematode - Helicotylenchus
Lance nematode - Hoplolaimus
Stunt or Stylet nematode - Tylenchorhynchus

12.  Establish a permanent feeding site inside plant tissues.
 Do not move after infection.
 Eggs are deposited in masses around the female body
on root surface.
 The posterior portion of the female body outside the roots
becomes swollen to varying degrees.
Examples:
Citrus nematode – Tylenchulus semipenetrans
Reniform nematode - Rotylenchulus reniformis

14.  The entire nematode is found inside the plant tissue.
 Complete their entire life cycle inside plant tissues.
Migratory endoparasites:
 These nematodes move in the cortical parenchyma of host
root.
 While migrating they feed on cells, multiply and cause
necrotic lesions.
 Eggs are scattered within the cortex.
 Remain vermiform
Examples:
Lesion nematode - Pratylenchus
Rice root nematode - Hirschmanniella
Burrowing nematode – Radopholus similis

16.  These nematodes establish a permanent feeding site
inside plant tissues.
 Do not move after infection
 Eggs are deposited in masses around the body of
females on root surface
Examples:
• Root-knot nematode – Meloidogyne spp.
• Cyst nematode – Heterodera,
Globodera

18. A. Above ground symptoms
B. Underground symptoms
A-Above ground symptoms
 Discolouration of foliage:
• G. rostochiensis infested potato
plants show light green foliage.

19.  Dead or devitalized buds:
• Aphelenchoides besseyi on
strawberry cause killing and dropping
off of flower buds
 Crinkled or distorted stem and foliage:
• The wheat seed gall nematode,
Anguina tritici infests the growing
point of wheat seedling as a result
distortions in stem and leaves take
place.

20.  Seed galls:
• Anguina tritici producing seed galls
in wheat.
 Leaf spots:
• Aphelenchoides fragariae
forms angular spots on the leaf
of strawberry.

21.  Root galls:
• Galling of roots is the most characteristic
symptom of attack of root knot nematodes,
Meloidogyne spp.
 Root lesion:
• Hirschemanniella cause brown lesion on
rice root.

22. Reduced root system:
Nematode feeding on the root tips may kill the growing point
and stop the further elongation of root.
• Belonolaimus longicaudatus infecting
maize resulting in coarse roots.
• Xiphinema cause curling of roots
known as “Fish hook” symptom.
.

23.  Excessive root branching:
• Meloidogyne hapla on tomato.
 Root rot:
• Ditylenchus destructor cause
root rot in potato.