580 Pflanzen (Botanik)
Refine
Year of publication
Document Type
- Article (3191)
- Part of Periodical (573)
- Book (60)
- Review (33)
- Working Paper (32)
- Doctoral Thesis (31)
- Report (29)
- Part of a Book (25)
- Periodical (14)
- Contribution to a Periodical (10)
Language
- German (2629)
- English (1206)
- French (52)
- Spanish (48)
- Multiple languages (36)
- cze (17)
- Latin (11)
- Portuguese (5)
- Italian (4)
- mis (2)
Is part of the Bibliography
- no (4013)
Keywords
- Pflanzengesellschaften (66)
- phytosociology (38)
- syntaxonomy (34)
- Festuco-Brometea (33)
- succession (28)
- Pflanzengesellschaft (27)
- conservation (27)
- species richness (24)
- Mitteleuropa (22)
- Bryophyta (21)
Institute
- Extern (101)
- Biowissenschaften (96)
- Institut für Ökologie, Evolution und Diversität (53)
- Senckenbergische Naturforschende Gesellschaft (39)
- Biodiversität und Klima Forschungszentrum (BiK-F) (29)
- Präsidium (13)
- SFB 268 (9)
- Universitätsbibliothek (8)
- Geowissenschaften / Geographie (7)
- Exzellenzcluster Makromolekulare Komplexe (5)
Phyllanthus novofriburgensis J.C.R.Mendes, J.M.A.Braga & Fraga sp. nov. and P. pedrosae J.C.R.Mendes, J.M.A.Braga & Fraga sp. nov. are new species of Phyllanthaceae described from the Brazilian Atlantic Forest and Brazilian Cerrado, respectively. Phyllanthus novofriburgensis resembles P. acutifolius Poir. ex Spreng., P. hypoleucus Müll.Arg. and P. lilliputianus J.C.R.Mendes, J.M.A.Braga & Fraga, sharing ovate, elliptical, and lanceolate leaf blades. However, it can be distinguished by its pendulous habit, often with sinuous branches and lanceolate leaf blades with characteristically revolute margins. Phyllanthus pedrosae exhibits morphological similarities with P. claussenii Müll.Arg. due to its subshrubby and prostrate habit. It is distinghuished by the unisexual inflorescence with cymules composed of one or two staminate flowers proximally positioned in the axil of the branches and solitary pistillate flowers distally situated, and the 5-merous calyx in the staminate and pistillate flowers. Both new species are classified in Phyllanthus subgen. Phyllanthus sect. Phyllanthus subsect. Clausseniani G.L.Webster, primarily due to the deeply emarginate anthers. Notes on their geographical distribution and habitat are provided, as well as a key to the species of Phyllanthus from Southeastern Brazil.
The fossil record of the diverse subfamily Passifloroideae (>750 species and 17 genera) is relatively poor. Despite the distinctiveness of its leaves (glandular and often emarginate), most of the fossils from this group have been described from seeds. Fossil seeds have been recovered from Europe, and North and South America. A lack of information on seed morphology for all the genera and tribes of this subfamily has prevented a tribe-level identification of the fossils and a better understanding of their biogeographic patterns. The Passifloroideae is divided into three tribes: Passifloreae with 10 genera, Paropsieae with six genera and the monotypic Jongkindieae. This study provides new descriptions for 15 species from 5 genera from the mostly Afrotropical tribe Paropsieae based on herbarium material, and introduces an online seed database and a key for 100 species of Passifloroideae compiled from literature and direct observations. Our study shows a low morphological diversity among the seeds of Paropsieae in comparison to a much larger diversity within Passifloreae. Some rare morphologies are only present in Passifloreae and can be used to assign seeds to this tribe. Within the Paropsieae, Androsiphonia has seed that are very distinct from those in the other genera in the tribe and also from the rest of the subfamily. The genus Paropsia exhibits two main morphotypes, while the genera Barteria, Paropsiopsis and Smeathmannia have very similar seeds with a highly conserved morphology. These results suggest that living or fossil Paropsieae cannot be identified confidently based solely on seed characters.
Forest wildflowers bloom earlier as Europe warms: lessons from herbaria and spatial modelling
(2022)
Today plants often flower earlier due to climate warming. Herbarium specimens are excellent witnesses of such long-term changes. However, the magnitude of phenological shifts may vary geographically, and the data are often clustered. Therefore, large-scale analyses of herbarium data are prone to pseudoreplication and geographical biases.
We studied over 6000 herbarium specimens of 20 spring-flowering forest understory herbs from Europe to understand how their phenology had changed during the last century. We estimated phenology trends with or without taking spatial autocorrelation into account.
On average plants now flowered over 6 d earlier than at the beginning of the last century. These changes were strongly associated with warmer spring temperatures. Flowering time advanced 3.6 d per 1°C warming. Spatial modelling showed that, in some parts of Europe, plants flowered earlier or later than expected. Without accounting for this, the estimates of phenological shifts were biased and model fits were poor.
Our study indicates that forest wildflowers in Europe strongly advanced their phenology in response to climate change. However, these phenological shifts differ geographically. This shows that it is crucial to combine the analysis of herbarium data with spatial modelling when testing for long-term phenology trends across large spatial scales.
Field work in the Kibira National Park (Burundi), located in the Kivu-Ruwenzori system of the Afromontane Region, revealed the existence of a new species clearly belonging to the Argocoffeopsis-Calycosiphonia clade (Coffeeae, Rubiaceae). The species shows striking heterophylly: the plagiotropous branches have several nodes bearing reduced or even scaly leaves. For the rest, it shares characters with Calycosiphonia and Kupeantha. Therefore, a morphological comparison with the clade is done, as well as molecular phylogenetic analyses. The morphology of the novelty is closer to Kupeantha than to Calycosiphonia, inter alia because the anthers have no transverse septa, in contrast to the multilocellate anthers of Calycosiphonia. However, the molecular data advocate for a position in Calycosiphonia – a result weakening the morphological distinction between Calycosiphonia and Kupeantha. The former genus is no longer restricted to species with transverse septa in the anthers and with placental outgrowths around the seed. The new species is formally described as Calycosiphonia albertina Ntore & Robbr. sp. nov. Nomenclaturally, this placement is also the most conservative option. A taxonomic treatment, illustrations, a geographical distribution map, and a preliminary conservation assessment are provided. The previous inclusion of Calycosiphonia pentamera in Kupeantha based on morphology is here corroborated by molecular analyses.
Diospyros L. is a large genus of flowering plants predominantly distributed in the tropics. It comprises over 700 species globally and around 300 are believed to occur in South-East Asia. Many species are economically important and exploited for the production of ebony wood and persimmons, yet taxonomic information on the genus is incomplete and inconsistent due to its morphological and nomenclatural complexity. Revisions of Diospyros in continental and insular South-East Asia were conducted independently by different authors, occasionally with different names used for the same species, or different species being given the same name in different countries. During our ongoing study of the genus Diospyros in Indochina (Cambodia, Laos, Thailand and Vietnam), we identified several such instances. Here, we clarify the most commonly misidentified species, including 1) D. apiculata Hiern, D. strigosa Hemsl. and D. tamiriensis Lecomte; 2) D. bejaudii Lecomte and D. retrofracta Bakh.; 3) D. dictyoneura Hiern and D. hasseltii Zoll.; 4) D. borneensis Hiern and D. fecunda H.R.Fletcher. Lectotypifications are also made for D. brachiata King & Gamble var. lanceolata H.R.Fletcher, D. fecunda, D. similis Craib and D. strigosa.
Abstract
Natural plant populations often harbour substantial heritable variation in DNA methylation. However, a thorough understanding of the genetic and environmental drivers of this epigenetic variation requires large-scale and high-resolution data, which currently exist only for a few model species. Here, we studied 207 lines of the annual weed Thlaspi arvense (field pennycress), collected across a large latitudinal gradient in Europe and propagated in a common environment. By screening for variation in DNA sequence and DNA methylation using whole-genome (bisulfite) sequencing, we found significant epigenetic population structure across Europe. Average levels of DNA methylation were strongly context-dependent, with highest DNA methylation in CG context, particularly in transposable elements and in intergenic regions. Residual DNA methylation variation within all contexts was associated with genetic variants, which often co-localized with annotated methylation machinery genes but also with new candidates. Variation in DNA methylation was also significantly associated with climate of origin, with methylation levels being lower in colder regions and in more variable climates. Finally, we used variance decomposition to assess genetic versus environmental associations with differentially methylated regions (DMRs). We found that while genetic variation was generally the strongest predictor of DMRs, the strength of environmental associations increased from CG to CHG and CHH, with climate-of-origin as the strongest predictor in about one third of the CHH DMRs. In summary, our data show that natural epigenetic variation in Thlaspi arvense is significantly associated with both DNA sequence and environment of origin, and that the relative importance of the two factors strongly depends on the sequence context of DNA methylation. T. arvense is an emerging biofuel and winter cover crop; our results may hence be relevant for breeding efforts and agricultural practices in the context of rapidly changing environmental conditions.
Author summary
Variation within species is an important level of biodiversity, and it is key for future adaptation. Besides variation in DNA sequence, plants also harbour heritable variation in DNA methylation, and we want to understand the evolutionary significance of this epigenetic variation, in particular how much of it is under genetic control, and how much is associated with the environment. We addressed these questions in a high-resolution molecular analysis of 207 lines of the common plant field pennycress (Thlaspi arvense), which we collected across Europe, propagated under standardized conditions, and sequenced for their genetic and epigenetic variation. We found large geographic variation in DNA methylation, associated with both DNA sequence and climate of origin. Genetic variation was generally the stronger predictor of DNA methylation variation, but the strength of environmental association varied between different sequence contexts. Climate-of-origin was the strongest predictor in about one third of the differentially methylated regions in the CHH context, which suggests that epigenetic variation may play a role in the short-term climate adaptation of pennycress. As pennycress is currently being domesticated as a new biofuel and winter cover crop, our results may be relevant also for agriculture, particularly in changing environments.
Abstract
Natural plant populations often harbour substantial heritable variation in DNA methylation. However, a thorough understanding of the genetic and environmental drivers of this epigenetic variation requires large-scale and high-resolution data, which currently exist only for a few model species. Here, we studied 207 lines of the annual weed Thlaspi arvense (field pennycress), collected across a large latitudinal gradient in Europe and propagated in a common environment. By screening for variation in DNA sequence and DNA methylation using whole-genome (bisulfite) sequencing, we found significant epigenetic population structure across Europe. Average levels of DNA methylation were strongly context-dependent, with highest DNA methylation in CG context, particularly in transposable elements and in intergenic regions. Residual DNA methylation variation within all contexts was associated with genetic variants, which often co-localized with annotated methylation machinery genes but also with new candidates. Variation in DNA methylation was also significantly associated with climate of origin, with methylation levels being higher in warmer regions and lower in more variable climates. Finally, we used variance decomposition to assess genetic versus environmental associations with differentially methylation regions (DMRs). We found that while genetic variation was generally the strongest predictor of DMRs, the strength of environmental associations increased from CG to CHG and CHH, with climate-of-origin as the strongest predictor in about one third of the CHH DMRs. In summary, our data show that natural epigenetic variation in Thlaspi arvense is significantly associated with both DNA sequence and environment of origin, and that the relative importance of the two factors strongly depends on the sequence context of DNA methylation. T. arvense is an emerging biofuel and winter cover crop; our results may hence be relevant for breeding efforts and agricultural practices in the context of rapidly changing environmental conditions.
Author Summary: Variation within species is an important level of biodiversity, and it is key for future adaptation. Besides variation in DNA sequence, plants also harbour heritable variation in DNA methylation, and we want to understand the evolutionary significance of this epigenetic variation, in particular how much of it is under genetic control, and how much is associated with the environment. We addressed these questions in a high-resolution molecular analysis of 207 lines of the common plant field pennycress (Thlaspi arvense), which we collected across Europe, propagated under standardized conditions, and sequenced for their genetic and epigenetic variation. We found large geographic variation in DNA methylation, associated with both DNA sequence and climate of origin. Genetic variation was generally the stronger predictor of DNA methylation variation, but the strength of environmental association varied between different sequence contexts. Climate-of-origin was the strongest predictor in about one third of the differentially methylated regions in the CHH context, which suggests that epigenetic variation may play a role in the short-term climate adaptation of pennycress. As pennycress is currently being domesticated as a new biofuel and winter cover crop, our results may be relevant also for agriculture, particularly in changing environments.
Tilletia caries and T. laevis, which are the causal agents of common bunt, as well as T. controversa, which causes dwarf bunt of wheat, threaten especially organic wheat farming. The three closely related fungal species differ in their teliospore morphology and partially in their physiology and infection biology. The gene content as well as intraspecies variation in these species and the genetic basis of their separation is unknown. We sequenced the genome of four T. caries, five T. controversa, and two T. laevis and extended this dataset with five publicly available ones. The genomes of the three species displayed microsynteny with up to 94.3% pairwise aligned regions excluding repetitive regions. The majority of functionally characterized genes involved in pathogenicity, life cycle, and infection of corn smut, Ustilago maydis, were found to be absent or poorly conserved in the draft genomes and the biosynthetic pathway for trimethylamine in Tilletia spp. could be different from bacteria. Overall, 75% of the identified protein-coding genes comprising 84% of the total predicted carbohydrate utilizing enzymes, 72.5% putatively secreted proteins, and 47.4% of effector-like proteins were conserved and shared across all 16 isolates. We predicted nine highly identical secondary metabolite biosynthesis gene clusters comprising in total 62 genes in all species and none were species-specific. Less than 0.1% of the protein-coding genes were species-specific and their function remained mostly unknown. Tilletia controversa had the highest intraspecies genetic variation, followed by T. caries and the lowest in T. laevis. Although the genomes of the three species are very similar, employing 241 single copy genes T. controversa was phylogenetically distinct from T. caries and T. laevis, however these two could not be resolved as individual monophyletic groups. This was in line with the genome-wide number of single nucleotide polymorphisms and small insertions and deletions. Despite the conspicuously different teliospore ornamentation of T. caries and T. laevis, a high degree of genomic identity and scarcity of species-specific genes indicate that the two species could be conspecific.
Due to massive energetic investments in woody support structures, trees are subject to unique physiological, mechanical, and ecological pressures not experienced by herbaceous plants. Despite a wealth of studies exploring trait relationships across the entire plant kingdom, the dominant traits underpinning these unique aspects of tree form and function remain unclear. Here, by considering 18 functional traits, encompassing leaf, seed, bark, wood, crown, and root characteristics, we quantify the multidimensional relationships in tree trait expression. We find that nearly half of trait variation is captured by two axes: one reflecting leaf economics, the other reflecting tree size and competition for light. Yet these orthogonal axes reveal strong environmental convergence, exhibiting correlated responses to temperature, moisture, and elevation. By subsequently exploring multidimensional trait relationships, we show that the full dimensionality of trait space is captured by eight distinct clusters, each reflecting a unique aspect of tree form and function. Collectively, this work identifies a core set of traits needed to quantify global patterns in functional biodiversity, and it contributes to our fundamental understanding of the functioning of forests worldwide.