Plant Parasitic Nematodes

• Plant Parasitic Nematodes

  - Thread – like unsegmented worms

  - Elongated and cylindrical in shape
• - Egg masses – located at posterior portion of female
• - With stylet – hollow – needle like spear located at the anterior portion
• - Behind the spear is a muscular esophagous with several digestive glands
• - As the nematode feeds, the stylet is inserted inside the plant cell and the plant juice is extracted by a sucking action
• - May mimic those of nutrient deficiency or drought even adequate mineral and water are available
• - The first symptom that appear is leaf chlorosis, followed by stunting and eventually death
• Galls

  are formed on the roots because of hypertrophy and hyperplasia, it may be formed on the leaves, seeds and floral parts
• Abnormal foliage coloration

  1. typical with mineral deficiency diseases results from root injury and malfunctioning. This inhibits the mineral uptake of the host
• Wilting

  1. results when nematodes injure the roots under a condition of moisture stress
• Leaf spots, distortion, twisting, swelling

  caused by stem and bulb nematodes
• Necrotic lesions

  – in roots and excessive branching result when nematodes feed on the root system

   
• The salivary secretion of nematodes contains enzymes that may be responsible for a variety of host responses such as: dissolution of cell walls and middle lamella, necrosis, hypertrophy, hyperplasia and growth inhibition.
• Disease Complex

  (a physiological malfunctioning caused by two or more pathogens) with fungi, bacteria, viruses and other nematodes.