Laboratory Exercise 15
Rev. 11/15/2012

Purpose:  Sedentary endoparasitic nematodes:  morphology, anatomy, biology, feeding habits -- Meloidogyne (Order Rhabditida, Suborder Tylenchina, Tylenchoidea, Heteroderidae).

1.   Powerpoint presentation and slides of characteristics.

2.   Inspect tomato roots infected with Meloidogyne incognita.  Note hyperplasia, galling.  Examine root surface for presence of egg masses. 

3.   Examine Meloidogyne incognita juveniles and males extracted from soil.  Examine stained roots for presence of other developmental stages.

4.   Dissect adult females from the tomato root system provided.  Place on a microscope slide in a small drop of lactic acid.  Carefully cut the perineal section from the posterior region of the female of each species and mount on a microscope slide for observation under the compound microscope.  Also try the "squash and roll" technique.

5.   Identify species of Meloidogyne from perineal patterns and protein patterns using the keys provided.

6.   Note the taxonomic position of the root-knot nematodes in the Order Rhabditida, Suborder Tylenchina.

7.   Anhydrobiosis Experiment (continued):

Objective:  To compare the survival of nematodes in soil allowed to dry for 5 and 12 days with that in soil kept moist. 
  • Questions:
    Are there differences in the survival rates of different nematode taxa or of nematodes with different feeding habits?
    Other than differential survival in dry and moist soils, are there other explanations for differences among the samples?
    Report findings to the class.

    8.   Videotapes

    9.   Homework Assignment:

         a) Soil Suppressiveness experiment.

    Push two microcosm cylinders into a soil of your choice and cap each end with a small petri dish to preserve an undisturbed core.  Label cylinders and bring to the next lab.

         b)  NEMAPLEX Exercise
              Main Menu:
                   Select...Biology and Taxonomy
                    Select..Phylogenetic Classification
                     Select...Order Rhabditida, Suborder Tylenchina
                    Review Meloidogyne, including M. incognita, M. hapla, M. javanica, and M. arenaria.  
               Return to Main Menu

     10.   NEMABASE Exercise

             Review the host range of nematodes in the genera Meloidogyne.  What are the indicated non-hosts?  Are there resistant cultivars available?
              From the Nemaplex main Menu, select Management and Decision Support, then Nemabase 2012.

             Alternatively, you can access the data from the descriptive page for each nematode. 

    Return to Nematology 100 Menu