Nematology 100
Final Examination, December 14, 1987
(2 hour exam, 100 points total)
I found the first 3 questions on a page labelled "Plant Nematology 118,
Examination May 28, 1958". It predates even my association with the
field, but I thought the questions were interesting.
(15 points)
1. Ditylenchus dipsaci, Ditylenchus destructor, and Ditylenchus angustus
are parasites of plants. Name at least one host plant of each and
indicate the part of the plant where you would expect to find each of the
nematode species.
(10 points)
2. A plant variety resistant to a Fusarium sp loses its resistance when
planted in a particular field in Louisiana. The resistant variety
performs well and retains its resistance in this field when the soil is
treated with Chloropicrin. Describe in detail the experiments that you
would undertake to determine the cause of the loss of resistance.
(10 points)
3. Assuming that Radopholus similis was found attacking citrus on 100
acres of citrus trees in groves in widely separated parts of California,
what measures would you take against this parasite if you were in charge
of a project designed to limit its spread and eliminate it from infested
groves? (Ferris addendum: what do you think about such a program?)
(16 points)
4. Briefly describe the technique that you would use to detect the
following nematodes:
a. Globodera rostochiensis in fallow soil
b. Meloidogyne incognita on cotton at mid growing season
c. Pratylenchus vulnus on bare root walnut nursery stock
d. Meloidogyne spp in fallow soil
e. Anguina tritici in wheat seed
f. Xiphinema americanum in an apple orchard
g. Ditylenchus dipsaci in garlic cloves
h. Mesocriconema xenoplax in a peach orchard
(30 points)
5. Briefly discuss the economic importance, distribution, host range,
injury to host, relation to host tissue, biology as influenced by
physical environment, and control of the following:
a. Bursaphelenchus xylophilus
b. Hemicycliophora arenaria
c. Xiphinema index
(20 points)
6. Match the following. (Some letters may be used several times, others
may not be used at all. There may be several answers to each question).
_________1. Animal parasite a) Caenorhabditis elegans
_________2. Can be cultured axenically b) Xiphinema index
_________3. Predator c) Ditylenchus destructor
_________4. Microbivorous d) Acrobeloides spp
_________5. Chemically mediated sex e) Seinura sp
attraction f) Pseudomonas solanacearum
_________6. Virus transmission g) Radopholus similis
_________7. A-rated pest (California) h) Trichinella spiralis
_________8. Migratory endoparasite i) Globodera rostochiensis
_________9. Order Tylenchida j) Ascaris suum
_________10.Nematode/bacterium interaction
(4 points)
7. Match the following:
_________1. W.B. Hewitt, D.J. Raski, a) 1913-1932 leader in the field of
and A.C. Goheen nematology in U.S.
_________2. N.A. Cobb b) reported the occurrence of a
_________3. B.G. Chitwood cyst nematode on sugarbeet in
_________4. J.R. Christie and V. Perry Germany in 1859.
_________5. M.J. Berkeley c) Pictorial key of plant nematodes.
_________6. H. Schacht d) First report of transmission of
_________7. J.N. Sasser plant viruses by nematodes.
_________8. W.F. Mai e) First demonstrated pathogenicity
of the ectoparasite, Trichodorus.
f) Separated Meloidogyne spp on the
basis of host differentials.
g) Separated Meloidogyne spp on the
basis of cuticular markings.
h) Reported galls on cucumber roots
in England.
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