Nematology 100: LECTURE 8

Rev. 01/01/2020

Nematodes Parasites of Higher Plants

       Complete Dorylaimida, Triplonchida, Virus Vectoring

Migratory Ecto/Endoparasites - Hoplolaimidae, Pratylenchidae

• Migratory endoparasites - increasing specialization?
• Overlapping esophageal glands.
• What changes in control of behavioral traits required? How is the behavior controlled? What are the signals?
• How inherited? Could the memory/instinct/control be destroyed to result in aberrant behavior - e.g. ectoparasitic feeding?

Hoplolaimidae

• Helicotylenchus multicinctus
• Hoplolaimus columbus
• Scutellonema brachyurum
• Scutellonema bradys

Pratylenchidae

• Pratylenchus
•     P. penetrans
•     P. vulnus

Are there common characteristics?

• The problem of host defense mechanisms - necrosis, hypersensitivity, phenolics.
• Apples - the replant problem
• Peaches - amygdalin, prunasin
• Management - resistance? - not much available, not specialized enough.
• Consider transgenic options with rootstocks: Mycogen corp (San Diego) has Bt gene effective against Pratylenchus.
• Chitinase genes (only effective against eggs?)
• Snowdrop lectin
• Studies with trichosanthin (ribosome inhibiting protein).
• Clean planting stock
• Site preparation - inoculum removal
• Rotation, cropping systems, nematicides
• Therapy - hot water/formalin, corm/rhizome surgery

Slides: