Laboratory Exercise 14
Rev. 11/13/2012

Purpose:  Semi-endoparasitic nematodes:  morphology, anatomy, biology, feeding habits -- Heterodera, Globodera, Punctodera and other cyst nematodes (Order Rhabditida, Suborder Tylenchina, Tylenchoidea, Heteroderidae).

 1.  Powerpoint presentation and slides of characteristics and damage by cyst nematodes.

 2.  Inspect Brussels Sprouts  roots to observe symptoms and specimens of Heterodera sp.

 3.  Stain Brussels Sprouts roots with acid-fuchsin/lactic acid (see Nemaplex Methods section); mount root pieces between two slides and distinguish various life stages of the cyst nematode.  Observe the syncytial feeding site.

 4.  Hand-pick males and juveniles of Heterodera sp. from Brussels Sprouts,
      Draw the nematodes observing the following characteristic features where appropriate:

          a)   stylet length and morphology
          b)   esophagus, type and anatomy, nature of postcorpus interface with intestine
          c)   male and female reproductive structures
          d)   general shape when heat-relaxed

 5.  Cut off the vulval cone and mount on a slide.  Determine whether the cysts are  bullate or abullate. Determine whether this nematode is Heterodera schachtii or H. cruciferae.

 6.  Examine the range of shapes of cysts of various species of Heteroderidae.

 7.  Note the taxonomic position of these nematodes in the Order Rhabditida, Suborder Tylenchina.

 8.  Examine the descriptive charts of these plant-parasitic nematodes.

 9.  Anhydrobiosis Experiment (continued):

Objective:  To compare the survival of nematodes in soil allowed to dry with that in soil kept moist.

10.  Videotapes:

          a)  Behavior of Heterodera species through the Life Cycle.
          b)  The Development of Heterodera schachtii.
          c)  Soybean Cyst Nematode Management.

11.   Homework Assignment:

        NEMAPLEX Exercise
          Main Menu:
               Select...Biology and Taxonomy
                Select..Phylogenetic Classification
                 Select...Rhabditida then Tylenchina
                           Review Heterodera, including H. schachtii,  
                           Review Globodera, including G. rostochiensis,  and G. pallida.  

 12.  NEMABASE Exercise

         Review the host range of nematodes in the genera Heterodera and Globodera.  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. 


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