Nematode Extraction Methods:Root Extraction Techniques

Kavitha GovindasamyJimmy R.RichMaria L .Mendes

A Plant-Parasitic Nematode

Sampling for Nematodes

Sampling and extracting for nematodes serves two purposes:

Diagnosis a current problem Predict a future problem

Objectives of sampling and extracting nematodes

Identify the nematode Population estimation Diagnose a nematode disease Make management decisions Regulatory purposes Research and surveys

Some Common Nematode Extraction Methods

Root Samples Jar incubation and sieving Blending and sieving Soil samples Baermann funnel Modified Baermann funnel Foliar samples Punching and incubating Scissors technique

Root Extraction Techniques:Jar Method

Principle

Nematodes are extracted based on their active migration from roots

Materials required

Glass jars and caps 325 or finer mesh sieve Labels and rubber bands Dark chamber

Sample ready for processing

Wash the roots

Damp dry the roots

Weigh the damp-dried roots

Place roots in jars, add water

Place jars in tray

Store in the dark for 72 hours

Following incubation, remove from storage and add water

Collect nematodes on sieve

Rinse nematodes from sieve

Nematode samples ready for observation

Advantages and Limitations

Advantages Extracts migratory endoparasitic nematodes Few materials needed Simple procedure to follow

Limitations Not useful for ectoparasitic nematodes Lack of aeration can be a problem Sieves are needed to concentrate nematodes

Root Extraction Techniques:Blending and Sieving

Principle

Nematodes are released from roots due to maceration.

Materials required

Blender 40 and 325 or 500 mesh sieves Pan or bowl Wire mesh Filter paper Squeeze bottle Weighing balance Scissors

Wash roots well

Cut roots

Damp dry the roots

Weigh roots

Place roots into blender, cover roots with water

Blend at low speed for 10-20 seconds

Pour the roots into 325 or finer mesh sieve

Set up a Baermann tray

Place filter paper on the Baermann tray

Add water to Baermann tray

Transfer the blended roots into the filter paper

Incubate for 24 hours

Remove roots from the pan

Pour the water in the dish through a 325 or fine mesh sieve

Concentrate nematodes for observation

Advantages and Limitations

Advantages Fast method to extract nematodes from roots Foliar nematodes can also be easily extracted

Limitations Chemicals released from the roots can be injurious to nematodes Blending for long time may damage nematodes

Acknowledgments

Janete Brito, Department of Plant Industry, Gainesville, Florida

Frank Woods, Nematode Assay Lab, University of Florida, Gainesville, Florida

Joey Orajay, Entomology and Nematology Department, University of Florida, Gainesville, FL

For additional information or comments, please contact:

Kavitha_nem@yahoo.com jimmyr@ufl.edu mlmendes@ufl.edu