Different type of nematodes & their symptoms

On the basis of feeding habitat, the nematode can be divided into following types that is ectoparasites, semi-endoparasites and endoparasites.

1. Presented By: MOHD SHARIQ 2014BTM15 DIFFERENT TYPES OF NEMATODES & THEIR SYMPTOMS

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

4. Types of Nematodes

5. Ectoparasites 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

6. Migratory ectoparasites

7. Sedentary ectoparasites 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

8. Sedentary ectoparasites

9. Semi- endoparasites 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

10. Migratory semi- endoparasites

11. Sedentary semi- endoparasites 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

12. Sedentary semi- endoparasites

13. Endoparasites 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

14. Migrat ory endoparasites

15. Sedentary endoparasites 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

16. S edentary endoparasites

17. Symptoms caused by nematodes Above ground symptoms Underground symptoms A-Above ground symptoms Discolouration of foliage: G. rostochiensis infested potato plants show light green foliage.

18. Continue… 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.

19. Continue… Seed galls: Anguina tritici producing seed galls in wheat. Leaf spots: Aphelenchoides fragariae forms angular spots on the leaf of strawberry.

20. B-Underground symptoms 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.

21. Continue… 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. .

22. Continue… Excessive root branching: Meloidogyne hapla on tomato. Root rot: Ditylenchus destructor cause root rot in potato .

23. Thank you.