scholarly journals An interactive key (Lucid) for the identifying of the genera of seed plants from the Ducke Reserve, Manaus, AM, Brazil

Rodriguésia ◽  
2012 ◽  
Vol 63 (1) ◽  
pp. 055-064 ◽  
Author(s):  
Volker Bittrich ◽  
Clara Sampaio D. Souza ◽  
Rubens L.G. Coelho ◽  
Milena V. Martins ◽  
Michael J.G. Hopkins ◽  
...  

The identification of Amazonian plants is still difficult for many reasons, one being the lack of collections over large areas of the region. As a consequence of the poor knowledge on the Amazonian flora, many taxonomic publications (revisions and floristic treatments) become out of date within a few years. In this context, the on-line publication of taxonomic treatises has been suggested, since it allows constant data updates; and this type of publication should therefore be more valued by the scientific community. An excellent field guide for the Ducke Reserve (Manaus, central Amazonian Brazil) was published, based exclusively on vegetative characters. However, the presence of reproductive structures in the collected material does not facilitate identification with this type of field guide. Furthermore, as in any printed key, the text cannot be updated, except through a new edition. As an example of a way to facilitate the identification of Amazonian plants, an interactive, multiple-entry key to the seed plant genera that occur in the Ducke Reserve was created using the program Lucid 3.5. The key includes vegetative and reproductive characters and many illustrations, and is available on-line. We discuss here the peculiarities and advantages of this type of electronic publication.

2017 ◽  
pp. 7
Author(s):  
Liz Y. Izquierdo ◽  
Rosalinda Tapia ◽  
Francisco Vergara ◽  
Elena Álvarez-Buylla

A fragment from an homologous sequence of LEAFY (LFY) gene that encodes for a transcription factor involved in early events during inflorescence development was cloned from genomic DNA of P. radiata, a non flowering seed plant. Using PCR technic we amplified an 85 bp fragment flanked by two primers designed from some DNA sequences obtained from different species of angiosperms. The fragment obtained was.highly similar to A. thaliana gene LFY between 5077 and 5143 bases and hybridized with a LFY clone from this species. This result suggests that sorne molecular components of the functional and structural complexity of the development of reproductive structures in higher plants are an ancestral property of seed plants and not a novelty in the angiosperm lineage.


2016 ◽  
Vol 1 (1) ◽  
Author(s):  
D.G. Shah ◽  
D.N. Mehta ◽  
R.V. Gujar

Bryophytes are the second largest group of land plants and are also known as the amphibians of the plant kingdom. 67 species of bryophytes have been reported from select locations across the state of Gujrat. The status of family fissidentaceae which is a large moss family is being presented in this paper. Globally the family consists of 10 genera but only one genus, Fissidens Hedw. has been collected from Gujarat. Fissidens is characterized by a unique leaf structure and shows the presence of three distinct lamina, the dorsal, the ventral and the vaginant lamina. A total of 8 species of Fissidens have been reported from the state based on vegetative characters as no sporophyte stages were collected earlier. Species reported from the neighboring states also showed the absence of sporophytes. The identification of different species was difficult due to substantial overlap in vegetative characters. Hence a detailed study on the diversity of members of Fissidentaceae in Gujarat was carried out between November 2013 and February 2015. In present study 8 distinct species of Fissidens have been collected from different parts of the state. Three species Fissidens splachnobryoides Broth., Fissidens zollingerii Mont. and Fissidens curvato-involutus Dixon. have been identified while the other five are still to be identified. Fissidens zollingerii Mont. and Fissidens xiphoides M. Fleisch., which have been reported as distinct species are actually synonyms according to TROPICOS database. The presence of sexual reproductive structures and sporophytes for several Fissidens species are also being reported for the first time from the state.


Phytotaxa ◽  
2021 ◽  
Vol 502 (3) ◽  
pp. 219-229
Author(s):  
JÉRÉMIE MOREL ◽  
JÉRÔME MUNZINGER

Three endemic species of Xyris (Xyridaceae, Poales) are currently recognized in New Caledonia. A recent multivariate analysis of 18 morphological characters based on 129 specimens of Xyris from New Caledonia, supported by 10 anatomical and micromorphological observations, suggested that three species should be recognized in the New Caledonian archipelago. However, the three published names did not correspond to the three entities identified via the multivariate analyses. The results showed that Xyris neocaledonia Rendle was morphologically distinct but requires lectotypification, Xyris guillauminii Conert was indistinct from X. pancheri Rendle, and that a new morphologically distinct species required description. We therefore propose to clarify the taxonomy of the genus for New Caledonia, by designating a lectotype, making this synonymy and describing the new species. The new species, Xyris desquamatus J.R.Morel & Munzinger, sp. nov., has the remarkable feature of leaves that are shed as the plant senesces, and is reflected in the specific epithet for this new species. Line drawings are provided for the new species, along with colour photos for the three New Caledonian Xyris species and a distribution map. Three identification keys are provided, the first based on vegetative characters, the second on reproductive characters and the third on anatomical features of the leaf. Xyris desquamatus is preliminarily assigned an IUCN risk of extinction assessment of vulnerable.


2020 ◽  
Vol 58 (1) ◽  
pp. 253-276 ◽  
Author(s):  
Dmitry Lapin ◽  
Deepak D. Bhandari ◽  
Jane E. Parker

The EDS1 family of structurally unique lipase-like proteins EDS1, SAG101, and PAD4 evolved in seed plants, on top of existing phytohormone and nucleotide-binding–leucine-rich-repeat (NLR) networks, to regulate immunity pathways against host-adapted biotrophic pathogens. Exclusive heterodimers between EDS1 and SAG101 or PAD4 create essential surfaces for resistance signaling. Phylogenomic information, together with functional studies in Arabidopsis and tobacco, identify a coevolved module between the EDS1–SAG101 heterodimer and coiled-coil (CC) HET-S and LOP-B (CCHELO) domain helper NLRs that is recruited by intracellular Toll-interleukin1-receptor (TIR) domain NLR receptors to confer host cell death and pathogen immunity. EDS1–PAD4 heterodimers have a different and broader activity in basal immunity that transcriptionally reinforces local and systemic defenses triggered by various NLRs. Here, we consider EDS1 family protein functions across seed plant lineages in the context of networking with receptor and helper NLRs and downstream resistance machineries. The different modes of action and pathway connectivities of EDS1 family members go some way to explaining their central role in biotic stress resilience.


2003 ◽  
Vol 46 (2) ◽  
pp. 149-161 ◽  
Author(s):  
Irene Queiro-Tajalli ◽  
Craig Campbell ◽  
John McNutt

Social work is unusual among the professions for its commitment to advocacy on behalf of the poor, the dispossessed and the disadvantaged. International human rights and the promotion of social and economic justice are clearly a part of this mission. The article addresses an emerging aspect of advocacy by examining the nexus between international social and economic justice issues and the social work response. It addresses the revolution in advocacy methods created by information technology. These new techniques can offer a wealth of opportunities to further develop the international advocacy component of the social work profession. The impacts these new methods can have on the creation of justice on a global level are discussed.


2013 ◽  
Vol 40 (4) ◽  
pp. 315 ◽  
Author(s):  
Donald F. Gaff ◽  
Melvin Oliver

In a minute proportion of angiosperm species, rehydrating foliage can revive from airdryness or even from equilibration with air of ~0% RH. Such desiccation tolerance is known from vegetative cells of some species of algae and of major groups close to the evolutionary path of the angiosperms. It is also found in the reproductive structures of some algae, moss spores and probably the aerial spores of other terrestrial cryptogamic taxa. The occurrence of desiccation tolerance in the seed plants is overwhelmingly in the aerial reproductive structures; the pollen and seed embryos. Spatially and temporally, pollen and embryos are close ontogenetic derivatives of the angiosperm microspores and megaspores respectively. This suggests that the desiccation tolerance of pollen and embryos derives from the desiccation tolerance of the spores of antecedent taxa and that the basic pollen/embryo mechanism of desiccation tolerance has eventually become expressed also in the vegetative tissue of certain angiosperm species whose drought avoidance is inadequate in micro-habitats that suffer extremely xeric episodes. The protective compounds and processes that contribute to desiccation tolerance in angiosperms are found in the modern groups related to the evolutionary path leading to the angiosperms and are also present in the algae and in the cyanobacteria. The mechanism of desiccation tolerance in the angiosperms thus appears to have its origins in algal ancestors and possibly in the endosymbiotic cyanobacteria-related progenitor of chloroplasts and the bacteria-related progenitor of mitochondria. The mechanism may involve the regulation and timing of the accumulation of protective compounds and of other contributing substances and processes.


2019 ◽  
Author(s):  
Xin Zhang

AbstractIn the ovule evolution, the integument is the most attention point in discussion as a morphologic character of the seed plants. There are several theories and hypotheses about the origin of the integument were presented in the history. However, the development and function of the ovule envelopes are not so clear until now. The development of thehe basal gymnosperms Cycas and Zamia were to investigated, especially of the integument to complement the existing knowledge in seed plants. The development of ovules of seed plant is documented with morphological and anatomical using LM and SEM.The nucellar beak found in Zamia is a structure that has not been recorded previously. It protrudes from the micropyle at pollination and may be the primary acceptor for pollen. There are striking similarities to the lagenostom or salpinx in Lyginopteridatae. There may be an evolutionary way to interpret the pollination drop existing in the Lyginopteridatae. Probably the nucellar beak of Cycads, even Ginkgoales have the same function with the lagenostom or salpinx of the Lyginopteridatea. Unfortunately, pollen and transport inside the pollination chambers have not been observed. Further analysis of this unusual structure seems to be very important.


2018 ◽  
pp. 18-24
Author(s):  
V. Doronin ◽  
Yu. Kravchenko ◽  
V. Dryga ◽  
M. Budovsky ◽  
V. Doronin

In the intensive arable farming the productivity of sugar beets depends on many factors: soil-climatic conditions, introduction of highly productive hybrids, quality pre-sowing seed treatment, use of updated machinery and technologies, fertilizers, reliable plant protection, high technological processing at sugar mills and others. All the mentioned factors can reduce the productivity of sugar beets considerably, but it is not possible to reach a maximum potential of crop productivity without the use of good-quality seeds of the latest hybrids. The quality of sugar beet seeds is formed during the growth, and it depends on several factors, and first of all on the quality of mother root crops – their mass, sizes, turgor, disease damage and others. Laboratory trials were carried out at the Institute of bio-energy crops and sugar beets of Ukraine’s NAAS, field trials were carried out in the conditions of Ivanivka research-breeding station in the years of 2016–2018. The trial scheme envisaged the planting of root crops, which were not damaged with root rot and damaged with root rot, a focal point of rot being removed before planting. During vegetation, seed plants were treated with fungicides at a bud stage (one–time treatment) and at a bud stage and the beginning of flowering (two–time treatment). Fungicides were not used in the control. Mother root crops, seed plants and seeds of a sugar beet hybrid, developed on the basis of cytoplasm male sterility Romul, were the object of the research. In the field trials the following was determined: viability of the root crops (the number of the emerged crops as to the number of the panted root crops) and the seed plant density at a full emergence stage and before harvesting. Agro-biological evaluation of the seed plant condition was made before harvesting – the number of non-productive seed plants (dried, infertile ones and others), the number of disease-damaged plants and the degree of their development. A record plot area of one replication was 20 m2 in field trials, a fourfold replication. The technology of seed plant cultivation is conventional, in accordance with the recommendations of the Institute of bio-energy crops and sugar beets of Ukraine’s NAAS. The paper covered some peculiarities of the yield formation and the quality of sugar beet seeds, depending on the quality of mother root crops. It was proved that the use of the root crops, partially damaged with rot during storage, and even when a focal point of rot was removed before harvesting, had an effect on the root crop viability (which was by 4.4 % lower), the formation of more non-productive plants – by 1.6–1.8 times – due to the increase of prematurely dried plants and infertile ones, which resulted in a serious yield decease – by 0.09-0.13 t/ha and seed quality – viability by 4 % and emergence by 6 %, as compared with the variants where health root crops were planted. Two-time spraying of the seed plants with fungicides resulted in the increase of the yield capacity and the seed quality in the variants where only partially rot-damaged root crops were planted. A tendency to the increase of the mentioned indicators, both in the variants with healthy root crops planted and with partially damaged root crops planted, was recorded under one-time spraying of the seed plants with fungicides. The research of the seeds gathered from the seed plants, which were grown from the root crops, disease-damaged and healthy ones, confirmed the results of the field trials. The viability of the seeds, received from the healthy (not disease-damaged) root crops was higher by 9 %, emergence – by 5 %, as compared with the root crops, partially rot-damaged, focal points of which were removed before planting. Key words: mother root crops, rot, productive seed plants, yield capacity, viability, germination.


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Upendo Lupanga ◽  
Rachel Röhrich ◽  
Jana Askani ◽  
Stefan Hilmer ◽  
Christiane Kiefer ◽  
...  

The V-ATPase is a versatile proton-pump found in a range of endomembrane compartments yet the mechanisms governing its differential targeting remain to be determined. In Arabidopsis, VHA-a1 targets the V-ATPase to the TGN/EE whereas VHA-a2 and VHA-a3 are localized to the tonoplast. We report here that the VHA-a1 targeting domain serves as both an ER-exit and as a TGN/EE-retention motif and is conserved among seed plants. In contrast, Marchantia encodes a single VHA-isoform that localizes to the TGN/EE and the tonoplast in Arabidopsis. Analysis of CRISPR/Cas9 generated null alleles revealed that VHA-a1 has an essential function for male gametophyte development but acts redundantly with the tonoplast isoforms during vegetative growth. We propose that in the absence of VHA-a1, VHA-a3 is partially re-routed to the TGN/EE. Our findings contribute to understanding the evolutionary origin of V-ATPase targeting and provide a striking example that differential localization does not preclude functional redundancy.


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