Search results for "Maran"

Ontogenetic and phylogenetic diversification of the hooded staminode in Marantaceae

2010

The flowers of Marantaceae are known for their unique pollination mechanism mediated by an explosive style movement. The mechanism is based on the highly modified elements of the inner androecial whorl, i.e., the single half-fertile anther and the fleshy and hooded staminodes. We investigated 67 species across 24 genera to elucidate which parts of the hooded staminode are shared by all species, thus likely under strong selection pressure, and which are allowed to vary. We treated hooded staminodes as character syndromes and grouped them based on gross similarities. We identified characters underlying the similarity and investigated their diversity and developmental pathways. All hooded stam…

Microwave heating as a tool for coupling Marangoni and Hickman instabilities

2007

The aim of this paper is the linear stability analysis of an evaporating interface in order to justify hydrodynamic behaviors observed during evaporation of water and ethanol simultaneously under microwave irradiation and reduced pressure. In relation to the local character of the thermal conversion of electromagnetic energy, and of the thermal dependency of the dielectric loss, it seems possible under microwave heating to induce a specific hydrodynamic compared to those induced by conventional heating.

Use of Heating Configuration to Control Marangoni Circulation during Droplet Evaporation

2022

The present work presents a numerical study of the evaporation of a sessile liquid droplet deposited on a substrate and subjected to different heating configurations. The physical formulation accounts for evaporation, the Marangoni effect, conductive transfer in the support, radiative heating, and diffusion–convection in the droplet itself. The moving interface is solved using the Arbitrary Lagrangian–Eulerian (ALE) method. Simulations were performed using COMSOL Multiphysics. Different configurations were performed to investigate the effect of the heating conditions on the shape and intensity of the Marangoni circulations. A droplet can be heated by the substrate (different natures and thi…

Studies on Instabilities and Patterns in Evaporating Liquids at Reduced Pressure and/or Microwave Irradiation

1990

This paper summarizes our recent experimental and theoretical work on the instabilities in liquids and at interfaces which form during evaporation at reduced pressure and/or microwave irradiation. We have observed a variety of patterns (Benard rolls, Marangoni waves, Hickman interface deformations) which depend on the value of the reduced pressure and the power of the incident beam.

Breeding system and fruit set in African Marantaceae

2013

Abstract Marantaceae are a pantropically distributed family of perennial herbs and lianas in the understory of tropical rainforests. They are characterized by a unique pollen transfer mechanism. To understand its functional significance and evolution, field investigations have been conducted in Gabon. Data from 28 (of 35) species from Central Africa are achieved. The pollen–ovule ratio (34–140:1; exception Sarcophrynium 2.5:1) falls into the range of facultative autogamous species. All investigated species were proven to be self-compatible; however, only two were autogamous. Natural fruit set was generally low (10.9 ± 10%). The highest natural fruit set was found in Marantochloa purpurea (2…

Pollination syndromes in African Marantaceae

2009

† Background and Aims The Marantaceae (550 spp.) is the most derived family in the order Zingiberales and exhibits a complex explosive pollination mechanism. To understand the evolutionary significance of this unique process of pollen transfer, comparative morphological and ecological studies were conducted in Gabon. † Methods During a total stay of 11 months, 31 species of Marantaceae were investigated at different sites in Gabon. The study included analyses of floral diversity, observations on the pollinator spectrum as well as ecological measurements (e.g. nectar sugar concentration and volume). † Key Results Analyses reveal five flower types based on flower size and pigmentation, spatia…

Phylogeny of Polycnemoideae (Amaranthaceae): Implications for biogeography, character evolution and taxonomy

2013

Molecular markers indicate the phylogenetic identity of southern Brazilian sea asparagus: first record of Salicornia neei in Brazil

2019

Abstract Molecular phylogenetic analyses based on ETS, ITS and atpB - rbcL spacer sequences assessed the phylogenetic status of the southern Brazil sea asparagus species of the genus Salicornia (Salicornioideae, Amaranthaceae). Accessions of Patos Lagoon estuary (32° S) were obtained from wild plants and two pure line lineages, selected from contrasting prostrate (BTH1) and decumbent (BTH2) ecomorphotypes found locally. Patos Lagoon wild plants, BTH1 and BTH2 f4 progenies showed 100% identical sequences for the atpB - rbcL and ITS spacers, only two mutations for ETS. Comparison of the sequences of these three markers with GenBank records confirmed the identity of Brazilian accessions as Sal…

On the hybrid origin of the C2Salsola divaricata agg. (Amaranthaceae) from C3 and C4 parental lineages

2021

AbstractC2 photosynthesis is characterized by recapturing photorespiratory CO2 by RuBisCO in Kranz-like cells and is therefore physiologically intermediate between C3 and C4 photosynthesis. C2 can be interpreted as an evolutionary precursor of C4 and/or as the result of hybridization between a C3 and C4 lineage.We compared the expression of photosynthetic traits among populations of the Salsola divaricata agg. (C2) from humid subtropical to arid habitats on the coasts of the Canary Islands and Morocco and subjected them to salt and drought treatments. We screened for enhanced C4-like expression of traits related to habitat or treatment. We estimated species trees with a transcriptome datase…

Chemical composition and herbicidal activity of the essential oil from a Cistus ladanifer population from Spain

2012

[EN] The essential oil composition of Cistus ladanifer grown in central Spain was analysed by gas chromatography and gas chromatography/mass spectrometry, revealing it to be rich in oxygenated compounds, with trans-pinocarveol (20.00%), bornyl acetate (7.03%) and terpinen-4-ol (6.37%) as the main monoterpene compounds. Viridiflorol (13.59%) and ledol (4.36%) were the main constituents of the oxygenated sesquiterpene fraction. Large amounts of-pinene (4.70%) were found in the hydrocarbonated fractions. To study its possible use as a natural herbicide, the oil was tested invitro against Amaranthus hybridus, Portulaca oleracea, Chenopodium album, Conyza canadensis and Parietaria judaica, compl…