Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme IV: POPULATION DYNAMICS AND ECOLOGY Posters
942 - Effect of arbuscular mycorrhiza (AM) on
seedlings of six endemic Mimosa species from semiarid
south-central Mexico
S.L. Camargo-Ricalde 1* , S.S. Dhillion 1 , C. Jiménez-
González 2 & R. González-Gómez 2
1 Agricultural University of Norway (NLH), Dept. Biology
and Nature Conservation (IBN), P.O. Box 5014, N-1432,
Ås, Norway. - 2 Universidad Autónoma Metropolitana-
Iztapalapa (UAMI), Dept. Biología, Apdo. POstal 55-535,
09340, D. F., Mexico. - E-mail: sara.camargo@ibn.nlh.no
We report on the effects of arbuscular mycorrhiza (AM) on
the growth of seedlings of six endemic Mimosa species: M.
adenantheroides, M. calcicola, M. lacerata, M. luisana, M.
polyantha and M. texana var. filipes. Seeds were collected
directly from plants. In the greenhouse, germination was
carried out in pots containing the soil of the localities
where the species occur. Ten seedlings per treatment per
species were examined. Treatments were applied once per
week: control, benomyl (B), phosphorus (P) and B+P.
Shoot length was measured twice per week. Plants were
harvested after seven months. Both root and shoot length
were measured, dry biomass quantified and shoot
phosphorus content; and AM root colonization percentage.
Seedlings treated with B had a significant lower growth
and less biomass than the other seedlings. Phosphorus
content was higher in the seedlings treated with P and P+B.
The highest AM colonization percentage was registered on
the seedlings treated with P and in the control. We found a
higher number of nodules in the seedlings treated with P.
Based on other parallel studies, after germination, which
takes place during the wet season, a fast growth favored by
AM symbiosis, may increase the survival probability of
seedlings in a harsh environment such as semiarid
ecosystem.
943 - Molecular ecology of root endophytes in an alpine
Bistorta vivipara - Kobresia myosuroides tundra plant
community
T.A. Carlsen * , K. Høiland & T. Schumacher
Div. of Botany and Plant Physiology, Dept. of Biology,
University of Oslo, P.O. Box 1045 Blindern, 0316 Oslo,
Norway. - E-mail: torac@bio.uio.no
A total of 210 endophyte axenic cultures from root tips of
22 plant species, including the ectomycorrhizal herb
species Bistorta vivipara and Kobresia myosuroides were
grouped according to culture morphology and HinfI and
HaeIII restricted ITS-RFLP groups. nrDNA ITS sequences
(98) from representative isolates of the 23 ITS-RFLP
groups were obtained. More than 90 % of the sequences
had affinities to the Helotiales (Ascomycota) and were
subjected to phylogenetic analyses in PAUP* with 47
sequences from GenBank. Altogether 39.5 % of the total
sample of root endophytes were referable to
Leptodontidium orchidicola. Phialophora finlandia was
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Book of Abstracts
recorded in four herbaceous plant species, i.e. Bartsia
alpina, Carex atrata, K. myosuroides and B. vivipara, and
most often in association with the ectomycorrhizal root tips
of B. vivipara and K. myosuroides. Axenic cultures of
Phialocephala fortinii were obtained from ectomycorrhizal
root tips of B. vivipara and K. myosuroides only. The L.
orchidicola ITS genotypes (31) were unevenly distributed
in four plots investigated. Hypotheses for host specificity
for fungal endophytic strains and possibilities of a common
fungal network are proposed.
944 - Effect of binucleate and multi-nucleate
Rhizoctonia spp. on seed germination and growth of
Anoectochilus formosanus Hayata
D.C.N. Chang * , L.C. Chou & G.C. Lee
National Taiwan University(NTU), Dept. of Horticulture,
Taiwan. - E-mail: hyha@ccms.ntu.edu.tw
Anoectochilus formosanus Hayata is a medical and
ornamental orchid in Taiwan. It was considered as a 'King
medicine'. Asymbiotic germination of A. formosanus in
Hyponex # 3 agar medium (H3A) was 65%. While
symbiotic germinations inoculated with binucleate
Rhizoctonia sp. (R02) or multi-nucleate Rhizoctonia sp.
(R04) in oat meal agar (OMA) medium were 42% and 31%
respectively. But the growth of symbiotic seedlings were
faster than those in asymbiotic medium (H3A). Both
binucleate (R02) and multi-nucleate (R04 and R05 )
Rhizoctonia spp. could enhance the growth of A.
formosanus plantlets in vivo. The binucleate Rhizoctonia
sp. R02 could be Rhizoctonia callae. By hyphal
anastomosis tests, the results showed that multi-nucleate
Rhizoctonia spp. (R04, R05, R06, R07, R09) belong to
AG-6 group. From RAPD data, using UPGMA clustering,
and light microscopy observation showed that that R03 and
R08 were Fusarium spp., and the other multi-nucleate
Rhizoctonia spp. were Rhizoctonia solani. It was suggested
that the inoculation of binucleate or multi-nucleate
Rhizoctonia spp. for A. formosanus plantlets in vivo could
promote their growth in practical use.
945 - Ecology of micro-fungi in mangrove sediments of
the Ganges river estuary in India
S. Chaudhuri * & A. Sengupta
Department of Plant Pathology,BCKV(Agriculture
University), Kalyani-741235, West Bengal, India. - E-mail:
mycolab@yahoo.com
Tidally inundated riverine sediments in the tropics at
outfall are inhabited by mangroves, the climax formation of
hydro-halophytes. Population dynamics and ecology of
micro-fungi in surface sediments of four floristically
different, nutrient limited mangrove succession stages at
the Ganges river estuary in India are reported. Population
density and species diversity of micro-fungi were inversely