TABLE CONTENTS

SESSION FORTY-SEVEN – NEMATODE BARCODING, BIODIVERSITY
AND ECOLOGY
CONVENORS: ANTOINETTE SWART & TOM POWERS
A New Globodera Cyst from South Africa
Knoetze, R. (1) & A. Swart (2)
(1) Directorate Plant Health, Department of Agriculture, Private Bag X5015, Stellenbosch, 7599 South Africa;
(2) Biosystematics Division, ARC-PPRI, Private Bag X134, Queenswood, 0121, South Africa
Nematode cysts from potato fields in the Sandveld area in South Africa were collected during
a delimiting survey for the presence of potato cyst nematodes in the region. Morphological
and molecular analysis of the cysts confirmed the presence of G. rostochiensis, as well as an
unknown Globodera species in the samples. The rDNA Internal Transcribed Spacer Region
of the nematodes were amplified by PCR and sequenced. The sequences obtained from some
populations were almost identical to G. rostochiensis sequences obtained from Genbank,
while sequences from other populations were not similar to either G. rostochiensis or G.
pallida., containing 38 point mutations and 12 insertions when compared to G. rostochiensis.
Morphologically the cysts of the unknown Globodera sp. varies in colour from yellow to
brown and are subspherical with a protruding neck. The vulval region is circumfenestrate and
in 50% of the cysts small or large cuticular thickenings (bullae or vulval bodies) are present
around the vulval basin, sometimes stretching to the anus and beyond. In some aspects this
species resemble G. rostochiensis (presence in potato fields and some aspects of the
morphology of the J2 and cyst), G. pallida (presence in potato fields and aspects of the
morphology of the J2 and cyst), G. achilleae (stylet of J2 and morphology of the cyst) and G.
millefolii (morphology of the cyst, especially the presence of bullae). The unknown cysts
showed no signs of hatching when incubated in potato root exudate at 20°C. Inoculation of
germinating potato tubers with larvae from the unknown Globodera sp. and incubation at
20°C did not result in any reproduction after 14 weeks. Low numbers of these cysts were
found in the soil and no damage was reported in this area. A number of indigenous plants and
weeds were screened as possible hosts of the cyst.
Connecting MOTUs and Morphology: Results from a Neotropical
Rainforest
Powers, T. (1), A. Esquivel (2), R. Giblin-Davis (3), P. Mullin (1), D. Neher (4), S.P. Stock
(5), M. Mora (6) & L. Uribe (6)
(1) Department of Plant Pathology, University of Nebraska, Lincoln, USA; (2) Facultad de Ciencias Agrarias,
Universidad Nacional Autónoma , Heredia, CR; (3)Institute of Food and Agricultural Sciences, University of
Florida, Fort Lauderdale, USA; (4) Plant and Soil Science Department, University of Vermont, Burlington,
USA; (5) Department of Entomology, University of Arizona, Tucson, USA; (6)Centro de Investigación en
Biologia Celular y Molecular, Universidad de Costa Rica, San José, CR
In March of 2005 nematode collections were made at La Selva Biological Research Station,
located near the Caribbean coast of Costa Rica. The objective was to determine the nematode
species diversity in the humid rainforest and to explore the possibility that nematode
communities were stratified among soil, litter, and understory habitats. An 18S ribosomal
barcode was used to generate 167 molecular operational taxonomic units (MOTUs) from 360
5 th International Congress of Nematology, 2008 172