There are several types of feeding strategies used by plant-parasitic nematodes. Some nematodes feed externally as ectoparasites using a long stylet, while others penetrate plant roots and form permanent feeding sites as semi-endoparasites or sedentary endoparasites. The most damaging nematodes are sedentary endoparasites like cyst nematodes and root-knot nematodes, which form specialized feeding cells that damage plant roots and reduce nutrient absorption. Other nematodes feed as they migrate within plant tissues as migratory endoparasites or infect aerial plant parts as stem, bulb, seed gall, or foliar nematodes, reducing plant health. Proper identification of nematode feeding strategies is important

1. Plant-nematode interactions
Anurag Kerketta
Assistant Professor/Scientist
CHRS, Jagdalpur

2. introduction
• feed on all parts of the plant, including roots, stems, leaves, flowers
and seeds.
• All use a specialized spear called a stylet. Note the differences in
stylet length and shape.
• Belonolaimus and Longidorus feed deep within the while
Helicotylenchus feeds on the exterior of the root or partially
burrows.

3. • Some nematodes do not kill the plant cells they feed upon but
“trick” the plant cells to enlarge and grow, thus producing one or
more nutrient-rich feeding cells for the nematode.
• Many plant-parasitic nematodes feed on the roots of plants.
The feeding process damages the plant's root system and
reduces the plant's ability to absorb water and nutrients.

4. Feeding strategy/behaviour
• There are seven major types of nematode feeding strategies used by
plant parasitic nematodes :
1. Ectoparasites.
2. Semi-endoparasites.
3. Migratory endoparasite
4. Sedentary endoparasite.
5. Stem and bulb nematodes.
6. Seed gall nematodes
7. Foliar nematodes.

5. Ectoparasites
• Can graze on numerous plants.
• have extremely long stylet.

6. • Xiphinema (dagger nematode),

7. Semi-endoparasites
• Usually the head of the nematode penetrates into the root and allows
the nematode to form a permanent feeding cell .
• Rotylenchulus reniformis, the reniform (kidney-shaped) nematode.
• Tylenchulus semipenetrans, the citrus nematode

8. Migratory endoparasites
• These nematodes cause massive plant tissue necrosis because of
their migration and feeding .
• No permanent feeding cells.
• Second-stage juvenile and starts feeding on the plant.
• Pratylenchus (lesion nematode), Radopholus(burrowing
nematodes) and Hirschmanniella (rice root nematode).

10. Sedentary endoparasites
• The most damaging nematodes in the world.
• Cyst nematodes (Heterodera and Globodera) and the root-knot
nematodes (Meloidogyne).
• Feeding cells of root-knot nematodes (giant cells) form by
repeated nuclear division in the absence of cell division.
• Cyst nematodes form by the incorporation of neighboring cells.
• The J2 nematodes inject secretions into and around the plant cells
to stimulate the formation of large feeder cell

11. Soybean cyst nematode (Heterodera glycines) .
Their remarkable persistence is due to their ability to produce a cyst.

13. Stem and bulb nematodes
• Ditylenchus spp. are, as their name suggests, attack the upper and
lower parts of plants.
• More damaging under wet conditions.
• Infectious stage -fourth stage juvenile.
•
• feed as migratory endoparasites .
•
• Fluffy masses of dried (cryptobiotic) Ditylenchus can be seen on
the surface of bulbs and are known as "nematode wool."

15. • Bursaphelenchus xylophilus (pine wood nematode)
• Nematodes are carried into pine tree in the tracheae of bark
beetles.
• Causing pine wilt disease.
• Able to feed on fungi in the tree.
• J3s are attracted to beetle larvae.

16. Seed gall nematodes
• Anguina spp. were the first plant-parasitic nematodes to be
described in the scientific literature in 1743.
• J2 feed as ectoparasites at the tips of leaves.
• J2 penetrates the floral primordia and starts to feed on the
developing seed.
• feed, and eventually kills the seed to form a blackened "cockle"
(seed gall) .

18. Foliar nematodes
• Genus Aphelenchoides.
• Adult penetrates through natural opening (Sromatoa) .
• Causes characteristic interveinal chlorosis and necrosis of the leaf,
ultimately killing it.

20. Summary of Plant Parasitic Nematode Feeding Strategies

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