NEMATOLOGY 100

Laboratory Exercise 13

Rev. 10/13/2008

Purpose:  Semi-endoparasitic nematodes:  morphology, anatomy, biology, feeding habits.

1.   Slide presentation of characteristics.

2.   Inspect citrus roots to observe symptoms and specimens of Tylenchulus semipenetrans.

3.   Hand-pick various life stages of Tylenchulus semipenetrans.
      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

4.   Examine stained citrus and grape roots to locate and recognize various life stages of these nematodes.

5.   Examine prepared slides of Rotylenchulus and Nacobbus spp.

6.   Note the taxonomic position of these nematodes in the order Tylenchida, suborder Tylenchina.

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

8.  Continue Lab Project:

• Count the nematodes that you extracted from your soil samples.
• Divide the suspension in half, save one half for future lab periods and centrifuge the other half. 
• Siphon off the supernatant and resuspend the pellet in the small volume of water remaining. 
• Place suspension on a microscope slide, immobilize nematodes with gentle heat, apply coverslip and seal. 
• Categorize 100 nematodes into functional guilds per lab handouts and instruction.
• Record data on sheet provided.

 

9.  Study photographs of characteristics and damage by citrus, reniform and false root-knot nematodes.

10.  Videotapes: a) The Citrus Nematode, Tylenchulus semipenetrans.

                        b) Heterodera schachtii feeding on rape seedlings.

11.   Homework Assignment:

        NEMAPLEX Exercise
         Main Menu:
               Select...Biology and Taxonomy
                Select..Phylogenetic Classification
                 Select...Tylenchida
               Select...Tylenchulidae
                           Review Tylenchulus, including T. semipenetrans.  
                           Review Cacopaurus, Trophonema and Sphaeronema.  
               Select...Hoplolaimidae
                           Review Rotylenchulus, including R. reniformis.
               Select...Pratylenchidae
                           Review Nacobbus, including N. aberrans.
           Return to Main Menu
           

   12.   NEMABASE Exercise

           Main Menu
            Select Decision Support

                       Select Host Status Database

 

Determine the host range for the genera Tylenchulus and Rotylenchulus.

In Nemabase select "All Plants" and "Genus" Tylenchulus and Rotylenchulus. 

Also examine the host range of individual species.
Set "Host" filter to Host.  Process.

 

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