Handbook Part 2 - International Mycological Association

S49PS2 - 0128
Morphological and molecular observations of Manglicola guatemalensis, a poorly known ascomycete
Satinee Suetrong, Jariya Sakayaroj, Souwalak Phongpaichit, E.B. Gareth Jones
1 Biotec Central Research Unit, Phathumthani, Thailand, 2 Department of Microbiology, Prince of Songkhla University,
Songkla, Thailand
Two collections of the poorly known ascomycete Manglicola guatemalensis from Trang and Trat (Koh Chang National
Park) Provinces, Thailand, were made in 2005 on the palm Nypa fruticans. This fungus is only known from two previous
collections (Kohlmeyer and Kohlmeyer, 1971; Hyde, 1988). This paper reports on the morphological characteristics and
molecular phylogeny of this unique marine bitunicate ascomycete. Manglicola guatemalensis has large clavate to
obtusely fusiform ascomata, wide ostiole surrounded by long hyaline hairs, bitunicate asci, deliquescing early to
release, unequally one-septate ascospores, constricted at the septum, apical cell larger, chestnut-brown and a small
light brown basal cell. Ascospores germinate readily, always from the basal smaller cell, which yield 8 isolates. Four
strains (from the different locations) were selected for the phylogenetic study. Kohlmeyer and Kohlmeyer (1971)
concluded that M. guatemalensis belonged in the Pleosporaceae / Venturiaceae, while Huhndorf (1992) erected a
new family, the Hypsostromataceae, for the genera Hypsostroma and Manglicola. Different regions of the rRNA gene
including SSU, ITS1-5.8S-ITS2 and LSU were sequenced. SSU sequences positioned M. guatemalensis in the Jahnulales
clade, but with weak bootstrap support (58%) based on the maximum parsimony analysis. Common features with the
Jahnulales include: stipitate ascomata, bitunicate asci, reticulate pseudo-paraphyses, bicelled brown ascospores.
Ascospores of M. guatemalensis superficially resemble Katumotoa bambusicola, assigned by Harada et al (2005) to
the Pleosporales. Manglicola guatemalensis differs from other bitunicate ascomycetes by large ascomata (1250 mm
X 425-500 mm) wide ostiole surrounded by long hyaline, straight hairs, large unequally bicelled ascospores and its
mangrove habitat growing on Rhizophora mangle and the frond base of N. fruticans. No clear phylogenetic resolution
can be advanced for the ITS and LSU rDNA sequences, as few are available for phylogenetic comparison.
1030-1230
SYMPOSIUM 50 - Mycetozoan Biodiversity
S50IS1 - 0155
Global diversity of cellular slime molds
J. C. Landolt 1, S. L. Stephenson 2, J. C. Cavender 3
1 Shepherd University, Shepherdstown, WV, United States, 2 University of Arkansas, Fayetteville, AR, United States,
3 Ohio University, Athens, OH, United States
In his 1984 monograph, Kenneth Raper listed approximately 50 described species of cellular slime molds (or
dictyostelids) that were assigned to three genera (Dictyostelium, Polysphondylium and Acytostelium). In 1989, just a
few years later, H. Hagiwara added a several more taxa to the group in his treatment of Japanese dictyostelids. Since
then, the number of dictyostelid taxa described in the literature has doubled, and additional forms likely to represent
new taxa are currently under analysis. The explanations for this expansion of dictyostelid biodiversity include such
things as a greater intensity of sampling in survey efforts by a number of researchers, sampling of habitats and
environments not previously surveyed, and an increasing body of evidence that some dictyostelid isolates previously
assigned to a species as a variation of a type are now, by virtue of being represented by additional isolates,
considered to deserve treatment as separate, distinct taxa. The utilization of molecular characters as well as
morphological ones has also contributed to supporting an increase in apparent variation in the group. This report will
attempt to summarize what is known about the biodiversity of dictyostelids throughout the world.
S50IS2 - 0142
A global perspective on myxomycete biodiversity
S. L. Stephenson
University of Arkansas, Fayetteville, Arkansas, United States
The myxomycetes (also called plasmodial slime molds or myxogastrids) are the largest and best known of the
eumycetozoans. Members of the group have been known from their fruiting bodies since at least the middle of the
seventeenth century. There are approximately 875 recognized species of myxomycetes, many of which have been
described in the past half century. The majority of species are probably cosmopolitan, but a few species seem to be
confined to the tropics or subtropics and some others have been collected only in temperate regions of the world.
Myxomycetes appear to be particularly abundant in temperate forests, but at least some species apparently occur
in any terrestrial ecosystem with plants (and thus plant detritus) present. Field-based studies carried out in many
different regions of the world over the past two decades have generated a considerable body of information that
has provided evidence for a number of ecological patterns not reported previously for myxomycetes while also
continuing to substantiate patterns or general observations that have long been suspected. Among the more
important of these are that (1) temperature and moisture are the two most important factors determining the
distribution and occurrence of myxomycetes in nature, (2) certain species of myxomycetes are invariably associated
with particular microhabitats such coarse woody debris or the bark surface of living trees, (3) species-rich temperate
deciduous forests are characterized by a level of myxomycete biodiversity that is as high or even higher than that of
tropical forests, (4) in tropical forests, distinct assemblages of myxomycetes are associated with microhabitats such as
aerial litter and the inflorescences of large herbaceous plants that have no counterparts in temperate forests, (5) the
assemblage of myxomycetes found in deserts is more diverse than realized previously, and (6) in spite of the fact that
the spores of myxomycetes would appear to have a high potential for dispersal, some species are much more
common in one region of the world than another, even when climate and vegetation of the two regions being
compared are fairly comparable. Although our knowledge of the biogeography, ecology and global distribution of
myxomycetes has increased considerably, there is still a need for additional research.
344