Fróðskaparrit - 01.07.2004, Síða 35

VAL AV LÍVØKI HJÁ ARBUSKULSOPPUM
í FØROYUM SAMMETT VIÐ AÐRASTAÐNI
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recombinant DNA molecule was trans-
ferred into competent E. coli cells (DH5a
from Gibco BRL Life Technologies). All
steps strictly followed the manufacturers’
manual. The competent cells were grown
on solid medium, forming colonies of iden-
tical clones. At least 16 clones were used
for each sample, giving a total of 244
clones.
RLFP
The clones were grouped by using the en-
zymes Hinfl and Hsp92U (Promega) main-
ly to distinguish between the glomalian
types, while Stul and Hpall were used to
detect amplified ascomycetes. Hpall did
also distinguish between some acaulospora
types. When all the ascomycetes were
omitted, only 127 clones were left.
T-RLFP
The results where an English site (Sour-
hope) is compared with Faroese sites are
obtained by T-RLFP (Liu et al., 1997). The
PCR products were digested with Hinfl and
then run on a Beckman Coulter CEQ8000.
The fragment length was analysed with
Beckman Coulter CEQ8000 software
(from Beckman Coulter).
Sequencing
Representatives for each main glomalean
group were sent for sequencing at the Tech-
nology Facility, University of York, UK.
Only one strand was sequenced. The se-
quencing was done on a Beckman Coulter
CEQ8000 analyser.
Statistics
ClustalX (Thompson et al., 1997) was used
for multiple alignment and neighbour-join-
ing phylogenetic analysis (Saitou and Nei,
1987), using Corallochytrium limacispo-
rum, a putative choanozoan (Cavalier-
Smith and Allsopp, 1996) as the outgroup.
The phylogenetic tree is drawn in TreeView
(Page, 1996). All other statistical analyses
were carried out using SPSS version 11.01.
Results
5 main types of AM fungi were found in
Agrostis capillaris roots (Table 1). A fur-
ther 10 types were found which only oc-
curred once or twice in total. Two of the
main types were mainly found at high alti-
tude, and two other were only found at low
altitude.
In total 16 types were found, although
not all of them are sequenced, and therefore
there might still be some ascomycetes in
the group. The unsequenced clones are 12
in total, so their importance is low com-
pared with the main group. To avoid a high
Shannon index due to undetected as-
comycetes, all the unsequenced clones
were omitted from the calculations, result-
ing in a Shannon index ranging from 0 to
1.19 (Table 1). However, if we remove the
altitude factor and only consider the aspect,
then the Shannon index is 1.63 on north-
facing slopes, 0.45 on south-facing (Table
2).
The very low diversity at south-facing
high altitude arises because only one of the
main types is found. This is “Glo3” which
seems to be a very competetive colonisator,
present in all studies mentioned in this