229 research outputs found
The hidden world within plants: ecological and evolutionary considerations for defining functioning of microbial endophytes
All plants are inhabited internally by diverse microbial communities comprising bacterial, archaeal, fungal, and protistic taxa. These microorganisms showing endophytic lifestyles play crucial roles in plant development, growth, fitness, and diversification. The increasing awareness of and information on endophytes provide insight into the complexity of the plant microbiome. The nature of plant-endophyte interactions ranges from mutualism to pathogenicity. This depends on a set of abiotic and biotic factors, including the genotypes of plants and microbes, environmental conditions, and the dynamic network of interactions within the plant biome. In this review, we address the concept of endophytism, considering the latest insights into evolution, plant ecosystem functioning, and multipartite interactions.EU Cost Action [FA1103, 312117]; FWF (Austrian Science Foundation) [P26203-B22, P24569-B25]; Portuguese FCT (Foundation for Science and Technology) [SFRH/BPD/78931/2011]info:eu-repo/semantics/publishedVersio
An overview of the taxonomy, phylogeny, and typification of nectriaceous fungi in Cosmospora, Acremonium, Fusarium, Stilbella, and Volutella
A comprehensive phylogenetic reassessment of the ascomycete genus
Cosmospora (Hypocreales, Nectriaceae) is undertaken using
fresh isolates and historical strains, sequences of two protein encoding
genes, the second largest subunit of RNA polymerase II (rpb2), and a
new phylogenetic marker, the larger subunit of ATP citrate lyase
(acl1). The result is an extensive revision of taxonomic concepts,
typification, and nomenclatural details of many anamorph- and
teleomorph-typified genera of the Nectriaceae, most notably
Cosmospora and Fusarium. The combined phylogenetic analysis
shows that the present concept of Fusarium is not monophyletic and
that the genus divides into two large groups, one basal in the family, the
other terminal, separated by a large group of species classified in genera
such as Calonectria, Neonectria, and Volutella. All accepted
genera received high statistical support in the phylogenetic analyses.
Preliminary polythetic morphological descriptions are presented for each
genus, providing details of perithecia, micro- and/or macro-conidial
synanamorphs, cultural characters, and ecological traits. Eight species are
included in our restricted concept of Cosmospora, two of which have
previously documented teleomorphs and all of which have
Acremonium-like microconidial anamorphs. A key is provided to the
three anamorphic species recognised in Atractium, which is removed
from synonymy with Fusarium and epitypified for two macroconidial
synnematous species and one sporodochial species associated with waterlogged
wood. Dialonectria is recognised as distinct from Cosmospora
and two species with teleomorph, macroconidia and microconidia are accepted,
including the new species D. ullevolea. Seven species, one with a
known teleomorph, are classified in Fusicolla, formerly considered a
synonym of Fusarium including members of the F. aquaeductuum
and F. merismoides species complex, with several former varieties
raised to species rank. Originally a section of Nectria,
Macroconia is raised to generic rank for five species, all producing
a teleomorph and macroconidial anamorph. A new species of the
Verticillium-like anamorphic genus Mariannaea is described
as M. samuelsii. Microcera is recognised as distinct from
Fusarium and a key is included for four macroconidial species, that
are usually parasites of scale insects, two of them with teleomorphs. The four
accepted species of Stylonectria each produce a teleomorph and micro-
and macroconidial synanamorphs. The Volutella species sampled fall
into three clades. Pseudonectria is accepted for a perithecial and
sporodochial species that occurs on Buxus. Volutella s. str.
also includes perithecial and/or sporodochial species and is revised to
include a synnematous species formerly included in Stilbella. The
third Volutella-like clade remains unnamed. All fungi in this paper
are named using a single name system that gives priority to the oldest generic
names and species epithets, irrespective of whether they are originally based
on anamorph or teleomorph structures. The rationale behind this is
discussed
Human-Mediated Emergence as a Weed and Invasive Radiation in the Wild of the CD Genome Allotetraploid Rice Species (Oryza, Poaceae) in the Neotropics
BACKGROUND: The genus Oryza is being used as a model in plant genomic studies although there are several issues still to be resolved regarding the spatio-temporal evolution of this ancient genus. Particularly contentious is whether undated transoceanic natural dispersal or recent human interference has been the principal agent determining its present distribution and differentiation. In this context, we studied the origin and distribution history of the allotetraploid CD rice genome. It is endemic to the Neotropics but the genus is thought to have originated in the Paleotropics, and there is relatively little genetic divergence between some orthologous sequences of the C genome component and their Old World counterparts. METHODOLOGY/PRINCIPAL FINDINGS: Because of its allotetraploidy, there are several potential pitfalls in trying to date the formation of the CD genome using molecular data and this could lead to erroneous estimates. Therefore, we rather chose to rely on historical evidence to determine whether or not the CD genome was present in the Neotropics before the arrival of Columbus. We searched early collections of herbarium specimens and studied the reports of explorers of the tropical Americas for references to rice. In spite of numerous collectors traveling inland and collecting Oryza, plants determined as CD genome species were not observed away from cultivated rice fields until 1869. Various arguments suggest that they only consisted of weedy forms until that time. CONCLUSIONS/SIGNIFICANCE: The spatio-temporal distribution of herbarium collections fits a simple biogeographical scenario for the emergence in cultivated rice fields followed by radiation in the wild of the CD genome in the Neotropics during the last four centuries. This probably occurred from species introduced to the Americas by humans and we found no evidence that the CD genome pre-existed in the Old World. We therefore propose a new evolutionary hypothesis for such a recent origin of the CD genome. Moreover, we exemplify how an historical approach can provide potentially important information and help to disentangle the timing of evolutionary events in the history of the Oryza genomes
Plantarum, in Horto medico Bonnensi nutritarum, Icones selectae
edi curaverunt et illustraverunt C. G. Nees ab Esenbeck et Th. Fr. L. Nees ab Esenbec
Die Evangelische Gemeine zu Boppard und Die schlechte Presse
DIE EVANGELISCHE GEMEINE ZU BOPPARD UND DIE SCHLECHTE PRESSE
Die Evangelische Gemeine zu Boppard und Die schlechte Presse ( - )
Einband ( - )
Werbung ( - )
Titelseite (1)
Text (3)
Werbung ( -
- …