TABLE CONTENTS

Comparison of Nematode Fauna of Plantings of Eucalyptus Species in the
Fleurieu Peninsula of South Australia.
Nobbs, J.M.
Plant and Soil Health, South Australian Research and Development Institute, South Australia 5001.
Soil was sampled randomly from five small plantings of Eucalyptus globulus (Tasmanian
Blue gum) present on a property located in Back Valley, Fleurieu Peninsula South Australia.
These plantations were 7, 5 and 3 years old and planted either close (2m) or wide (4m) apart.
The original vegetation consisted of mainly small stands of remnant pink gum (Eucalyptus
fasciculosa) with braken as the understory. The braken was sprayed before cultivation in
preparation for planting. Nematodes were extracted from the soil and the nematode fauna
observed and counted. The nematodes were separated into 5 main trophic groups (free-living
dorylaims, predators, bacterial feeders, fungal feeder and plant parasites). Nematodes within
each trophic groups was further separated into general morphological groups depending on
genera or sub-family. The nematode fauna was then compared between plantings and
significant differences were found. A diversity index was also calculated. The highest
numbers and diversity of nematodes was found in the 7 year old stand of wide spaced trees.
The lowest number and diversity was found in one of the 3 year old closely spaced plantings.
Comparisons were also made between the plantings of Eucalyptus globulus and 5 year old
stands of wide spaced trees of Eucalyptus saligna (Sydney blue gum), Corymbia maculata
(Spotted gum), Eucalyptus occidentalis (Flat top yate), Eucalyptus cladocalyx (Sugar gum)
and Eucalyptus fasciculosa (Pink gum). There were significant differences between all stands
of gums and the numbers and composition of the different nematode groups. There was a
gradual increase in nematodes the older the plantings of trees although there was also an
effect seen of topography and soil within the sample area.
Development of PCR-DGGE for Nematode Community Analysis: Selection
of a PCR Primer Set
Oba, H. (1), H. Okada (1) & W. Abe (1,2)
(1) National Institute for Agro-Environmental Sciences, 3-1-3, Kan'nondai, Tsukuba-city, Ibaraki, 305-8604,
Japan; (2) University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
To develop PCR-DGGE for nematode community analysis, we compared four primer sets
(nem1-nem2 ( gnem1 h): Foucher and Wilson 2002, NEMF1-NEM896r ( gNEM h):
Waite et al. 2003, MN18F-22R ( gMN h): Bhadury et al. 2006 and SSU18A-SSU9R/GC
( gSSU h): Okada and Oba, in press). A database survey showed that SSU and nem1 had
no remarkable mismatches between any nematode sequences, while not less than three bases
mismatches were found in NEM and MN. In addition, no amplification from several species
of order Rahabditida was observed with NEM. Next, we tested bands resolution on DGGE
gel. SSU and NEM produced clear bands. However, nem1 and MN produced faint band.
Profiles of cloning library of four nematode samples constructed with SSU and NEM were
compared to conventional method (hCONV h). Three families (Nordiidae, Nygolaimidae,
Leptolaimidae) observed by CONV were not detected with both primer sets, but these taxon
were minor. Four families of the order Chromadorida and Rahabditida were not detected with
NEM. NEM had another disadvantage: it produced multiple bands even from cloned single
sequence, probably because the degenerate sequence in the primer design. To examine
quantitative performance of SSU, we prepared artificial communities by mixing nine species
5 th International Congress of Nematology, 2008 270