•The phalanx type of clonal growth dominates in the studied populations.•Genetic diversity decreases with decreasing genet population size.•Ramet fine-scale spatial genetic structure is high and ...affected by clonality.•Fine-scale spatial genetic structure is stronger in small populations.
Small populations often show a low degree of genetic diversity. In distylous clonal plants, genetic diversity may also be influenced by other factors, such as floral morph aggregation, clonality and spatial genetic structure. Nevertheless, the relationships between population size, genetic diversity and spatial genetic structure are poorly understood. We tested for the effects of population size on genetic diversity and fine-scale spatial genetic structure (FSGS) in the clonal, distylous aquatic herb Menyanthes trifoliata. To investigate genetic diversity and structure, we used microsatellite markers and genotyped a total of 510 ramets from nine populations in southern Belgium. The populations showed a relatively high degree of genetic diversity (HEc=0.80; A12=4.45), even if both expected heterozygosity and allelic richness significantly decreased with decreasing population size (genet numbers). Populations were significantly genetically differentiated (FST=0.14), indicating reduced gene flow among populations. Morph ratio for genets did not deviate from 1:1. The phalanx type of clonal growth dominated in the studied populations. Ramet FSGS (which was strongly affected by clonality) was significant in all populations. Sp statistic significantly decreased with increasing population size, indicating higher FSGS in smaller populations. Consequently, small populations may suffer from a higher rate of geitonogamous pollination (between ramets of the same genet). Since M. trifoliata is a strongly self-incompatible herb, no inbred seeds can be produced from self- (and geitonogamous) pollination. In this case, reproductive success of small and more spatially structured populations of M. trifoliata may be reduced due to clogging of stigmas with incompatible pollen. We conclude that understanding genetic diversity and fine-scale clonal structure is crucial for conservation of self-incompatible plant species with extensive clonal propagation.
Two new species of Amanitasect.Phalloideae are described from tropical Africa (incl. Madagascar) based on both morphological and molecular (DNA sequence) data.
Amanitabweyeyensis
sp. nov.
was ...collected, associated with
Eucalyptus
, in Rwanda, Burundi and Tanzania. It is consumed by local people and chemical analyses showed the absence of amatoxins and phallotoxins in the basidiomata. Surprisingly, molecular analysis performed on the same specimens nevertheless demonstrated the presence of the gene sequence encoding for the phallotoxin phallacidin (PHA gene, member of the MSDIN family). The second species,
Amanitaharkoneniana
sp. nov.
was collected in Tanzania and Madagascar. It is also characterised by a complete PHA gene sequence and is suspected to be deadly poisonous. Both species clustered together in a well-supported terminal clade in multilocus phylogenetic inferences (including nuclear ribosomal partial LSU and ITS-5.8S, partial
tef1
-α,
rpb2
and β-tubulin genes), considered either individually or concatenated. This, along with the occurrence of other species in sub-Saharan Africa and their phylogenetic relationships, are briefly discussed. Macro- and microscopic descriptions, as well as pictures and line drawings, are presented for both species. An identification key to the African and Madagascan species of Amanitasect.Phalloideae is provided. The differences between the two new species and the closest
Phalloideae
species are discussed.
is a lamellate genus in the family Boletaceae that has been recently described from China based on
, the only known species. Typical characters of
are reddish-orange to yellowish-red basidiomata, ...including lamellae, bright yellow basal mycelium and smooth, broadly ellipsoid, ellipsoid to nearly ovoid basidiospores. During our survey on diversity of Boletaceae in Thailand, several yellowish-orange to reddish- or brownish-orange lamellate boletes were collected. Based on both morphological evidence and molecular analyses of a four-gene dataset (
6,
1,
2 and
3), they were recognised as belonging in
and different from the already known species. Two new species,
and
are therefore introduced from Thailand with detailed descriptions and illustrations. Moreover, two previously described
species,
and
, were also revised and recombined in
. A key to all known
species is provided.
Pulveroboletus fragrans
, a new bolete species with a strong aromatic odor, was found in forests dominated by
Castanopsis
and
Lithocarpus
(Fagaceae) in Northern Thailand. The species is introduced ...with macroscopic and microscopic descriptions and illustrations, as well as a three-gene phylogenetic analysis that confirms its position within the
Pulveroboletus
clade of Boletaceae.
Pulveroboletus fragrans
can be easily distinguished from all other
Pulveroboletus
species by its strong aromatic odor, the violaceous to purple color of the uppermost part of the stipe, and viscid general veil covering the pileus and stipe. The nature of the general veil is discussed.
Boletus longipes
was described in 1909 by George Massee from a specimen collected in Singapore. The species was not mentioned again until E.J.H. Corner’s book in 1972 on Malaysian boletes. Corner had ...collected it many times during his tenure in Singapore, and he synonymized
Boletus tristis
with
B. longipes
described nine years after
B. longipes
by Patouillard and Baker from the same site. Among the distinguishing characters of
B. longipes
were deep vinous red spore deposit, red oxidation reaction of the hymenophore when bruised, and spores that displayed a strong violet color reaction in contact with KOH. C.B. Wolfe ultimately moved both species to a new genus
Austroboletus
. During recent efforts to circumscribe
Austroboletus
in Australasia using morphological and molecular phylogenetic inferences, it became clear that
B. longipes
was neither in harmony with
Boletus
,
Porphyrellus
, nor
Austroboletus
. Rather, it is a new genus, which we describe here as
Ionosporus
, allied to
Borofutus
,
Spongiforma
, and
Rhodactina
of subfamily Leccinoideae. In addition, recent collections from Queensland and New South Wales, Australia, that are morphologically similar to
I. longipes
, are inferred to be a separate new species,
I. australis
.
The genus Agaricus includes cultivated species of nutritional and medicinal interest, such as A. bisporus and A. subrufescens. The latter and A. flocculosipes were the only species of the A. sect. ...Arvenses that have been reported from Thailand. In this section, we introduce Agaricus subtilipes, a new species from North Thailand. Bayesian and maximum likelihood phylogenetic analyses of internal transcribed spacer (ITS) ribosomal RNA gene showed that this new species is sister to A. flocculosipes. A comparison of Agaricus subtilipes with tropical species of A. sect. Arvenses led us to revisit the species A. bambusae. Unexpectedly, A. bambusae var. bambusae which was described from Africa was shown to be a synonym of Agaricus subrufescens based on molecular data. In contrast, A. bambusae var. australis which was described from New Zealand was not closely related to A. subrufescens, but was a sister species to A. subantarcticus, also described from this country; this variety is therefore raised to species rank and renamed as A. horakianus. In experimental cultivation, an isolate of A. subtilipes fructified on compost substrate with conditions used for A. subrufescens cultivation. This first fruiting test showed that A. subtilipes can be domesticated, however further investigations are required to optimize conditions for industrial yields.
•A new species, Agaricus subtilipes was described from north Thailand.•A wild strain of A. subtilipes fructified at 25 °C and 95% humidity.•Agaricus bambusae var. bambusae was synonymized with A. subrufescens.•Agaricus bambusae var. australis was renamed as A. horakianus.
•We identified the S-genotype of 13 North Western European pear cultivars.•All described cultivars differed by their S-genotypes.•Several identified S-alleles were rare alleles.
Due to the ...gametophytic self-incompatibility of European pear (Pyrus communis), S-compatible cultivars that flower synchronically are required in commercial pear orchards to ensure effective pollination and fruit production. The gametophytic self-incompatibility is controlled by a single locus (S-locus) encoding a polymorphic stylar ribonuclease (S-RNase) and pollen-specific expressed F-box genes (SFBB). Both the S-RNase and the SFBB genes are multi-allelic and are ideal markers for molecular S-genotyping. In the present study, we genotype the S-locus of thirteen North Western European pear cultivars by sequencing their S-RNases. All the described cultivars diverged by their S-allele combinations and six of them had unique S-genotype so that they are at least semi-compatible with all the 150 previously described cultivars and could be potentially interesting pollinator cultivars for commercial orchards.
This paper sorts out the taxonomy of species affiliated with
Pulveroboletusravenelii
in the Guineo-soudanian and Zambezian woodlands of Africa. Morphological and genetic characters of African
...Pulveroboletus
collections were studied and compared to those of North American and Asian species. A phylogenetic analysis showed that the African specimens form a subclade, sister to the Asian and American taxa. Although clamp connections have previously never been reported from
Pulveroboletus
, all specimens of the African subclade show very small clamp connections. Two new African species,
Pulveroboletusafricanus
sp. nov.
and
P.sokponianus
sp. nov.
, are described and illustrated. Comments concerning morphology and identification, as well as distribution and ecology, are given for both species.
Ganoderma sichuanense ( Ganodermataceae ) is a medicinal mushroom originally described from China and previously confused with G. lucidum . It has been widely used as traditional medicine in Asia ...since it has potential nutritional and therapeutic values. We collected 8 specimens of Ganoderma species from Thailand and show that they represent the first record of G. sichuanenese for Thailand. In this paper, we describe our specimens of Ganoderma sichuanense based on fresh basidiomes, and provide line drawings and photographs. The data from macro- and microscopic features are consistent with the characteristics of the species. Analysis of ITS sequence data indicates that the Thai collections cluster in same species clade as the epitype of G. sichuanense .
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