While numerous studies have revealed that arbuscular mycorrhizal fungi (AMF) enhance plant performance, the influence of these symbionts on temperate-forest herbaceous species in relation to soil ...physical and chemical properties has been left largely unexplored. Therefore, two perennial herbs, Geum urbanum (Rosaceae) and Senecio ovatus (Asteraceae), were examined in a laboratory pot experiment to determine whether AMF influenced their growth, photosynthetic performance index, and N and P contents in biomass. The treatments, involving three widespread AMF species, were prepared in the soils of two habitats colonised by both plants, namely beech and riparian forests, as follows: (1) control-soils without AMF, (2) Claroideoglomus claroideum, (3) Funneliformis geosporus, and (4) Funneliformis mosseae. Neither shoot mass nor photosynthetic performance index of G. urbanum and S. ovatus was enhanced by AMF. Senecio ovatus root mass was increased compared to control only by F. geosporus. Inconsistent effects were observed in N and P contents in shoots and roots of both species. The direction and magnitude of these responses were dependent on the fungal species and soil type. Although the plant species belong to families whose representatives are usually regularly colonised by and highly responsive to AMF, our study indicates that AMF had only a slight impact on the performance of G. urbanum and S. ovatus at the early stages of their development. The plants being slightly dependent on AMF are thus adapted to colonise temperate-forest soils with a low level of availability of AMF propagules.
Aim
Overstorey tree species influence both soil properties and microclimate conditions in the forest floor, which in turn can induce changes in ground bryophyte communities. The aim of the study was ...to investigate the effect of tree species identity and the most important habitat factors influencing understorey bryophytes.
Methods
We assessed the effect of 14 tree species and related habitat parameters, including soil parameters, vascular plant presence and light intensity on bryophytes in monospecific plots covered by nearly fifty-year-old trees in the Siemianice Experimental Forest (Poland).
Results
The canopy tree species determined bryophyte species richness and cover. The strongest differences were observed between plots with deciduous and coniferous trees. Soils with a more acidic pH and lower content of macronutrients supported larger bryophyte coverage. We also found a positive correlations between vascular plants and availability of light as well as bryophyte species richness.
Conclusion
Tree species identity and differences in habitat conditions in the forest floor lead to changes of ground bryophyte richness, cover and species composition. Consequently, the changes in the dominant tree species in the stand may result in significant repercussions on ground bryophyte communities. We indicated that the introduction of alien tree species, i.e.
Quercus rubra
, has an adverse effect on bryophyte communities and suggested that the selection of tree species that contribute to the community consistent with the potential natural vegetation is highly beneficial for maintaining ground bryophyte biodiversity.
Background and Aims Viola tricolor L. (heartsease, wild pansy) is a valuable medicinal plant obtained for pharmaceutical purposes by cultivation. Given that the species is usually strongly colonized ...by arbuscular mycorrhizal fungi (AMF), we tested in a pot experiment whether these microorganisms were able to influence V. tricolor mass, vitality, and the concentrations of selected elements, phenolic acids and flavonoids. Methods The following treatments were prepared: (1) control: sterile soil without AMF inoculation; (2) Rhizophagus irregularis BEG144; (3) Funneliformis mosseae BEG12; and (4) both isolates. Using a combination of physiological, phytochemical and biophysical methods, we evaluated the effects of these AMF on the performance of heartsease. Results The intensity of mycorrhizal colonization and arbuscule formation was higher when F. mosseae and R. irregularis were introduced separately than when both isolates were present. None of the AMF treatments had an impact either on V. tricolor vitality as expressed by photosynthetic performance index (PI) or on its shoot and root mass. However, in general, a negative correlation was found between the extent of mycorrhizal colonization and shoot mass. We found AMF species specificities in their influence on element, phenolic acid and flavonoid concentrations. Viola tricolor showed no response to F. mosseae. The plants inoculated with R. irregularis had higher concentrations of P, Zn, Mg, and Ca, as well as p-hydroxybenzoic acid and rutin, in comparison to control. Dual AMF species inoculation increased concentrations of Cu, Mg and rutin. Conclusions The enhanced production of secondary metabolites in V. tricolor shoots may be due to improved mineral nutrition by AMF and/or a result of general plant defense reaction to fungal colonization. The tendency towards biomass decrease in AMF treatments could be explained by the allocation of plant carbon both to the maintenance of symbionts and enhanced production of secondary compounds.
Hypericum perforatum L. (St. John’s-wort, Hypericaceae) is a valuable medicinal plant species cultivated for pharmaceutical purposes. Although the chemical composition and pharmacological activities ...of H. perforatum have been well studied, no data are available concerning the influence of arbuscular mycorrhizal fungi (AMF) on this important herb. A laboratory experiment was therefore conducted in order to test three AMF inocula on H. perforatum with a view to show whether AMF could influence plant vitality (biomass and photosynthetic activity) and the production of the most valuable secondary metabolites, namely anthraquinone derivatives (hypericin and pseudohypericin) as well as the prenylated phloroglucinol—hyperforin. The following treatments were prepared: (1) control—sterile soil without AMF inoculation, (2) Rhizophagus intraradices (syn. Glomus intraradices), (3) Funneliformis mosseae (syn. Glomus mosseae), and (4) an AMF Mix which contained: Funneliformis constrictum (syn. Glomus constrictum), Funneliformis geosporum (syn. Glomus geosporum), F. mosseae, and R. intraradices. The application of R. intraradices inoculum resulted in the highest mycorrhizal colonization, whereas the lowest values of mycorrhizal parameters were detected in the AMF Mix. There were no statistically significant differences in H. perforatum shoot mass in any of the treatments. However, we found AMF species specificity in the stimulation of H. perforatum photosynthetic activity and the production of secondary metabolites. Inoculation with the AMF Mix resulted in higher photosynthetic performance index (PItotal) values in comparison to all the other treatments. The plants inoculated with R. intraradices and the AMF Mix were characterized by a higher concentration of hypericin and pseudohypericin in the shoots. However, no differences in the content of these metabolites were detected after the application of F. mosseae. In the case of hyperforin, no significant differences were found between the control plants and those inoculated with any of the AMF applied. The enhanced content of anthraquinone derivatives and, at the same time, better plant vitality suggest that the improved production of these metabolites was a result of the positive effect of the applied AMF strains on H. perforatum. This could be due to improved mineral nutrition or to AMF-induced changes in the phytohormonal balance. Our results are promising from the biotechnological point of view, i.e. the future inoculation of H. perforatum with AMF in order to improve the quality of medicinal plant raw material obtained from cultivation.
As a result of phylogenomic, phylogenetic, and morphological analyses of members of the genus
, four potential new glomoid spore-producing species and
, a new order, Entrophosporales, with one ...family, Entrophosporaceae (=Claroideoglomeraceae), was erected in the phylum Glomeromycota. The phylogenomic analyses recovered the Entrophosporales as sister to a clade formed by Diversisporales and Glomeraceae. The strongly conserved entrophosporoid morph of
, provided with a newly designated epitype, was shown to represent a group of cryptic species with the potential to produce different glomoid morphs. Of the four potential new species, three enriched the Entrophosporales as new
species,
, and
, which originated from Argentina, Sweden, Oman, and Poland. The fourth fungus appeared to be a glomoid morph of the
epitype. The physical association of the
entrophosporoid and glomoid morphs was reported and illustrated here for the first time. The phylogenetic analyses, using nuc rDNA and
concatenated sequences, confirmed the previous conclusion that the genus
in the family Entrophosporaceae sensu Oehl et al. is an unsupported taxon. Finally, the descriptions of the Glomerales, Entrophosporaceae, and
were emended and new nomenclatural combinations were introduced.
Three new species of arbuscular mycorrhizal fungi of the genus Diversispora (phylum Glomeromycota) were described based on their morphology and molecular phylogeny. The phylogeny was inferred from ...the analyses of the partial 45S rDNA sequences (18S-ITS-28S) and the largest subunit of RNA polymerase II (rpb1) gene. These species were associated in the field with plants colonizing maritime sand dunes of the Baltic Sea in Poland and formed mycorrhiza in single-species cultures.
Examination of fungal specimens collected in the Atlantic rain forest ecosystems of Northeast Brazil revealed many potentially new epigeous and semihypogeous glomerocarp-producing species of the ...phylum Glomeromycota. Among them were two fungi that formed unorganized epigeous glomerocarps with glomoid spores of almost identical morphology. The sole structure that distinguished the two fungi was the laminate layer 2 of their three-layered spore wall, which in spores of the second fungus crushed in PVLG-based mountants contracted and, consequently, transferred into a crown-like structure. Surprisingly, phylogenetic analyses of sequences of the 18S-ITS-28S nuc rDNA and the
gene indicated that these glomerocarps represent two strongly divergent undescribed species in the family Glomeraceae. The analyses placed the first in the genus
, and the second in a sister clade to the monospecific generic clade
with
. The first species was described here as
sp. nov. Because
is the first glomerocarp-forming species in
, the generic description of this genus was emended. The very large phylogenetic distance and the fundamental morphological differences between the second species and
suggested us to introduce a new genus, here named as
gen. nov., and name the new species
sp. nov. In addition, our analyses also focused on an arbuscular mycorrhizal fungus originally described as
, later transferred to the genus
. The analyses indicated that this species does not belong to any of these two genera but represents a new clade at the rank of genus in the Glomeraceae, here described as
gen. nov.
Studies of the morphology and the 45S nuc rDNA phylogeny of three potentially undescribed arbuscular mycorrhizal fungi (phylum Glomeromycota) grown in cultures showed that one of these fungi is a new ...species of the genus
in the family Diversisporaceae; the other two fungi are new
species in Scutellosporaceae.
sp. nov. came from maritime sand dunes of the Vistula Spit in northern Poland, and
sp. nov. and
sp. nov. originally inhabited the Mediterranean dunes of the Peloponnese Peninsula, Greece. In addition, the morphological description of spores of
, originally described in 1988, was emended based on newly found specimens, and the so far unknown phylogeny of this species was determined. The phylogenetic analyses of 45S sequences placed this species among
species with atypical phenotypic and histochemical features of components of the two inner germinal walls.
Phylogenetic analyses of sequences of the nuc rDNA small subunit (18S), internal transcribed spacer (ITS1-5.8S-ITS2 = ITS), and large subunit (28S) region (= 18S-ITS-28S), as well as sequences of ...this region concatenated with sequences of the largest subunit of RNA polymerase II (
RPB1
) gene, proved that the species originally described as
Acaulospora polonica
(phylum
Glomeromycota
) represents a new genus and a new family of the ancient order Archaeosporales, here introduced into the
Glomeromycota
under the names
Polonospora
and
Polonosporaceae
, respectively. The phylogenetic analyses and BLASTn queries also indicated that the
Polonosporaceae
with
P. polonica
comb. nov. still contains several morphologically undescribed taxa at the ranks of genus and species, which have a worldwide distribution.
Morphological analyses of three glomoid spore-producing fungi suggested that two of them were undescribed species of
Glomeraceae
(phylum
Glomeromycota
), and the third differed slightly from
...Dominikia glomerocarpica
and
Epigeocarpum crypticum
, recently described in
Glomeraceae
. The first two fungi originated from the Mediterranean Sea sand dunes of the Peloponnese, Greece, and the third was originally found in a tree plantation in Yokohama City, Japan. Phylogenetic analyses of sequences of the 45S nuc rDNA region and the
RPB1
gene showed that (i) the three fungi belonged to
Glomeraceae
; (ii) the first two represented a new genus, here described as
Complexispora
gen. nov. with
C. multistratosa
sp. nov. and
C. mediterranea
sp. nov. and (iii) the third enlarged the monospecific genus
Epigeocarpum
, as
E. japonicum
sp. nov.
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