Morphological and Anatomical Variations of Roots, Leaves, Peduncles, and Peduncle Bracts in the Vriesea oligantha Complex (Bromeliaceae): Perspectives for Taxonomy

2020 ◽  
Vol 45 (4) ◽  
pp. 779-793
Author(s):  
Kleber Resende Silva ◽  
Leonardo M. Versieux ◽  
Aline Oriani
Keyword(s):  
Morphological Diversity ◽  
Anatomical Variations ◽  
Reproductive Organs ◽  
Minas Gerais ◽  
Vascular Bundles ◽  
Adaptive Responses ◽  
Channel Diameter ◽  
Species Complexes ◽  
Intraspecific Variations ◽  
Peltate Trichomes

Abstract—Vriesea is one of the genera of Bromeliaceae with the highest morphological diversity, including species of difficult recognition, many of them forming complexes, such as the Vriesea oligantha alliance. Morphological and anatomical comparative studies of vegetative and reproductive organs proved to be useful to solve such species complexes, besides indicating adaptive radiation. We analyzed comparatively the anatomy of roots, leaves, peduncles, and peduncle bracts of different populations found in rocky fields of Minas Gerais and Bahia, Brazil, with a taxonomic goal. In all the individuals studied the roots are composed of a velamen, a heterogeneous cortex, and a polyarch vascular cylinder, features that are common in the family. The leaves are covered by peltate trichomes and exhibit a hypodermis on both sides of the blade and a chlorenchyma composed of arm cells forming air lacunae between the collateral vascular bundles. The presence of subepidermal fiber strands in the leaves differentiates the populations of Minas Gerais from those of Bahia. The peduncle has an atactostele with compactly arranged cells in the cortex and pith. The peduncle bracts exhibit a greater number of peltate trichomes on the abaxial surface and secretory channels occur in the mesophyll. A cluster analysis (UPGMA) based on leaf morphology and tank channel diameter generated a dendrogram with four main clusters, which correspond to V. lancifolia, V. oligantha, and V. pseudoligantha, plus another taxon. Intraspecific variations in the color and margin shape of leaves and peduncle bracts are interpreted as adaptive responses to environmental factors, mainly luminosity.

scholarly journals An Anatomical Study of Scilla (Scilloideae) Section Chionodoxa and Scilla bifolia in Turkey1

2017 ◽  
Vol 35 (0) ◽  
Author(s):  
H. YILDIRIM ◽  
K. YETISEN ◽  
A. ÖZDEMIR ◽  
C. ÖZDEMIR
Keyword(s):  
Numerical Analysis ◽  
Numerical Methods ◽  
Analysis Of Variance ◽  
Leaf Anatomy ◽  
Pearson Correlation ◽  
Anatomical Study ◽  
Anatomical Variations ◽  
Vascular Bundles ◽  
Single Row ◽  
Scilla Bifolia

ABSTRACT In the present study Scilla luciliae, S. forbesii, S. sardensis, S. siehei, Scilla x allenii and S. bifolia are compared anatomically. Some differences have been found in root, scape, and leaf anatomy of the taxa, and commented. S. luciliae, S. forbesii, S. sardensis and S. siehei have a metaxylem at the center of the root, others have 3-4 number metaxylem. Vascular bundles in two row in S. luciliae and S. forbesii in a single row in S. sardensis, Scilla x allenii and S. bifolia though in three rows in S. siehei. Aerenchyma tissue is present in mesophyll of five taxa leaf except S. sardensis. The anatomical variations in the taxa have been investigated by means of numerical methods (Analysis of variance and Pearson correlation). By the analysis of the investigated taxa from 12 anatomy related characters, it has been also found that the results from numerical analysis of anatomy characters can provide additional evidences, which correspond to the anatomy for the recognition of the taxa.

scholarly journals Morphological diversity of fish along the rio das Velhas, Minas Gerais, Brazil

2012 ◽  
Vol 10 (2) ◽  
pp. 417-424 ◽  
Author(s):  
Nara Tadini Junqueira ◽  
Cecília Gontijo Leal ◽  
Carlos Bernardo Mascarenhas Alves ◽  
Paulo Santos Pompeu
Keyword(s):  
Fish Assemblages ◽  
Morphological Diversity ◽  
Minas Gerais ◽  
Two Dimensions ◽  
Anthropogenic Pressures ◽  
Morphological Attributes ◽  
Morphological Organization ◽  
Minas Gerais State ◽  
Major Tributary ◽  
Euclidean Distances

The rio das Velhas, located in central Minas Gerais State (Brazil), is a major tributary of the rio São Francisco. Despite several anthropogenic pressures, this basin supports more than 115 fish species. The aim of this study was to compare the morphological space occupied by fish assemblages in four regions (headwaters, upper, middle, and lower course) along the channel of the rio das Velhas. We try to answer the following question: Is there a change in the morphological organization of the fish along the longitudinal gradient of the river? Individuals from 67 species, collected at several sites in the basin from 1999 to 2008, were measured for 11 morphological attributes related to swimming behavior and habitat use. Through the graphs, the first two dimensions of the PCA suggest that the morphological volume occupied by the headwaters region is smaller than the other sections, because of the low richness of the site. However, morphological hypervolumes of the four reaches analyzed by Euclidean distances were not statistically different. The results indicated that only the density of morphological types increases along the rio das Velhas, and there is no difference between the headwaters and upper courses. Therefore, in order to use functional groups related to the morphology of the species as tools to take measures for the conservation and revitalization of the rio das Velhas, it is necessary analyze the density of species within these groups, as well as their composition.

Shifting functional roles and the evolution of conifer pollen-producing and seed-producing cones

Paleobiology ◽  
2011 ◽  
Vol 37 (4) ◽  
pp. 587-602 ◽  
Author(s):  
Andrew B. Leslie
Keyword(s):  
Biotic Interactions ◽  
Morphological Diversity ◽  
Reproductive Organs ◽  
Sensu Stricto ◽  
Morphological Data ◽  
Strong Interactions ◽  
Geologic History ◽  
Functional Roles ◽  
Primary Driver ◽  
Reproductive Evolution

Exploring patterns in the evolution of seed plant reproductive morphology within a functional context offers a framework in which to identify and evaluate factors that potentially drive reproductive evolution. Conifers are a particularly useful group for studies of this kind because they have a long geologic history and their reproductive organs are borne on separate structures with discrete functions. Multivariate analysis of morphological data collected from pollen-producing and seed-producing cones of Paleozoic, Mesozoic, and extant conifer species shows that seed cones underwent a significant expansion of morphological diversity that began during the Early-Middle Jurassic and has continued into the present day. In contrast, pollen cones show significantly lower levels of morphological diversity and exhibit similar basic morphologies throughout conifer evolutionary history. The increase in seed cone diversity through time is primarily the result of two novel structural and organizational features that evolved independently in different conifer families during the Mesozoic: robust, tightly packed cones in members of Araucariaceae, Cupressaceae sensu lato, and Pinaceae, and highly reduced, fleshy cones or solitary seeds in Podocarpaceae, Taxaceae, and some members of Cupressaceae sensu stricto. In extant conifers, these cone morphologies are associated with species that have strong interactions with vertebrate seed predators, seed dispersers, or a combination of both. This suggests that increases in the strength and complexity of biotic interactions in the Jurassic and Cretaceous were a primary driver of conifer reproductive evolution, and that patterns of character evolution relate to the increasing importance of cone tissue in seed protection and seed dispersal through time.

scholarly journals Reproductive Ontogeny and the Evolution of Morphological Diversity in Conifers and Other Plants

2019 ◽  
Vol 59 (3) ◽  
pp. 548-558 ◽  
Author(s):  
A B Leslie ◽  
J M Losada
Keyword(s):  
Morphological Evolution ◽  
Morphological Diversity ◽  
Developmental Rate ◽  
Reproductive Organs ◽  
Developmental Trajectory ◽  
Evolutionary Significance ◽  
Developmental Patterns ◽  
Functional Roles ◽  
Form And Function ◽  
And Function

Abstract Biologists often study morphological evolution through form and function relationships. But biological structures can perform multiple functional roles, complicating efforts to understand the evolutionary significance of any one relationship. Plant reproductive organs perform multiple roles in a sequence, however, which provides a unique opportunity to understand how structures evolve to meet multiple functional demands. Using conifers as a study group, we discuss how a shared developmental trajectory links the performance of sequential functional roles. Variation in development among lineages can underlie morphological diversity; pollination-stage seed cones in Pinaceae conifers function similarly but show diverse forms reflecting differences in developmental rate. As cones develop further, the morphologies that they use to perform later functional roles are influenced by the specific developmental patterns used to meet earlier demands, which may ultimately limit morphological diversity. However, we also show how selective pressures relating to the final functional stage (seed dispersal) may influence cone anatomy and morphology over all previous stages, highlighting the complex linkages among form, function, and development. We end by discussing the potential relationships between functional ontogeny and morphological disparity in plant reproductive structures more broadly, suggesting that the complex functional roles associated with seed plant reproduction probably underlie the high disparity in this group.

scholarly journals Morphological characterization of seeds in Portulacaceae

Phytotaxa ◽  
2013 ◽  
Vol 141 (1) ◽  
pp. 1 ◽  
Author(s):  
Gilberto Ocampo
Keyword(s):  
Cell Walls ◽  
Individual Cell ◽  
Morphological Diversity ◽  
Morphological Characterization ◽  
Seed Morphology ◽  
Important Variation ◽  
Species Complexes ◽  
Multiple Samples

Portulacaceae is a monogeneric family with around 100 species distributed around the world. Seed morphology is diverse in this group, and its variation has been used for taxonomic and identification purposes. However, documentation of seed morphology has focused on a few species complexes or has been limited to specific countries and geographic areas. Moreover, the terminology employed in different investigations is heterogeneous, thus complicating analyses of seed morphological diversity in Portulacaceae. In this study, the seed morphology of 58 samples representing 49 species, 9 subspecies, and 2 cultivars of Portulaca was documented with the use of scanning electron microscopy (SEM). Based on the examination of the resulting images, a set of morphological features for describing the general shape of the seeds and their individual cell features is proposed; in addition, morphological descriptions for all taxa included in this study are provided. The results indicate that the shape of the seeds was constant within species, contrary to the characters that describe individual cell features, which showed important variation even within the same seed sample. In particular, the outline of the cells and the curvature of the anticlinal cell walls (ACW) were very variable, so a combination of character states was needed to describe the overall diversity of a sample. Conversely, the relief of the periclinal cell walls (PCW) was relatively constant throughout the seeds of the same species, but the relief of the cells of the lateral and peripheral faces was dissimilar in a number of taxa. In addition, other studies provide evidence that the relief of the PCW may vary in widely distributed species. Increased taxon sampling and multiple samples of species with wide geographical ranges will facilitate the study of patterns of variation, and may provide insights into the role of environmental variables on seed diversity of Portulacaceae.

Six new species of Agalliopsis from Southeastern Brazil (Insecta: Hemiptera: Cicadellidae: Agalliinae)

Zootaxa ◽  
2009 ◽  
Vol 2014 (1) ◽  
pp. 1-18 ◽  
Author(s):  
ANA CLARA GONÇALVES ◽  
GABRIEL MEJDALANI1 ◽  
LUCI B. N. COELHO
Keyword(s):  
New Species ◽  
Atlantic Forest ◽  
New Taxa ◽  
Color Pattern ◽  
Minas Gerais ◽  
Southeastern Brazil ◽  
Male And Female ◽  
Species Complexes ◽  
Minas Gerais State

Six new species of Agalliopsis Kirkaldy, 1907 are described from the Atlantic Forest of Southeastern Brazil (Minas Gerais State): A. variegata sp. nov., A. dutrai sp. nov., A. chaelata sp. nov., A. pentaspinata sp. nov., A. mutabilis sp. nov., and A. felixi sp. nov. Illustrations of external features and male and female genitalic characters that distinguish the new taxa are given. Variation in the color pattern and male genitalic characters of A. mutabilis is recorded. The new taxa are assigned to species complexes within Agalliopsis.

scholarly journals Response of phytohormone homeostasis to heat stress and the roles of phytohormones in rice grain yield: a review

2019 ◽  
Author(s):  
Chao Wu ◽  
She Tang ◽  
Ganghua Li ◽  
Shaohua Wang ◽  
Shah Fahad ◽  
...  
Keyword(s):  
Heat Stress ◽  
Grain Yield ◽  
Grain Filling ◽  
Reproductive Organs ◽  
Reproductive Stage ◽  
Grain Weight ◽  
Rice Grain ◽  
Vascular Bundles ◽  
Rice Varieties ◽  
Heat Effects

Rice is highly susceptible to heat stress at the reproductive stage. In this review, we first summarize recent progress in heat effects on rice grain yield during different reproductive stages. Different responses of yield traits of rice to heat stress during different reproductive stages are identified. The number of spikelets per panicle is reduced by heat stress during the early reproductive stage but is not affected by heat stress during the mid-late reproductive stage. Spikelet sterility induced by heat stress can be attributed primarily to physiological abnormalities in the reproductive organs during flowering but attributed to structural and morphological abnormalities in reproductive organs during panicle initiation. The lower grain weight caused by heat stress during the early reproductive stage was due to a reduction in non-structural carbohydrates, undeveloped vascular bundles, and a reduction in grain length and width, while a shortened grain filling duration, reduced grain filling rate, and decreased grain width affect grain weight when heat stress occurs during grain filling. Phytohormones play vital roles in regulating plant adaptations against heat stress. We discuss the processes involving phytohormone homeostasis (biosynthesis, catabolism, deactivation, and transport) in response to heat stress. It is currently thought that biosynthesis and transport may be the key processes that determine phytohormone levels and final grain yield in rice under heat stress conditions. Finally, we prospect that screening and breeding rice varieties with comprehensive tolerance to heat stress throughout the entire reproductive phase could be feasible to cope with unpredictable heat events in the future. Studies in phytohormone homeostatic response are needed to further reveal the key processes that determine phytohormone levels under heat condition.

Taxonomy, palynology, and seed morphology of Paepalanthus decumbens, a new species of Eriocaulaceae from Minas Gerais, Brazil

2018 ◽  
Vol 151 (2) ◽  
pp. 252-261
Author(s):  
Marcelo Trovó ◽  
Wellerson L. Picanço ◽  
Vânia Gonçalves-Esteves
Keyword(s):  
New Species ◽  
Pollen Grains ◽  
Morphological Diversity ◽  
Minas Gerais ◽  
Seed Morphology ◽  
Morphological Description ◽  
Campos Rupestres ◽  
Floral Characters ◽  
First Time ◽  
A New Species

Background and aims – Paepalanthus is the largest genus of Neotropical Eriocaulaceae and the largest genus of Brazilian monocots. Much of its taxonomic and morphological diversity remains unknown. A new species is described, with details on pollen and seed morphology.Methods – The morphological description of the vegetative and floral characters was made using a stereoscopic microscope with camera. Pollen and seed samples from the new species and from two related taxa were studied under light microscopy and scanning electron microscopy.Key results – Paepalanthus decumbens is described and illustrated, including details of pollen grains and seeds. The species is restricted to a small area in the campos rupestres of Serra de São José (Minas Gerais, Brazil), and therefore should be considered as critically endangered. The decumbent stem, falciform leaves with long trichomes along the margins, the numerous and sericeous scapes of roughly the same size of the leaves, and the dark castaneous involucral bracts are useful features for the recognition of the new species. Paepalanthus decumbens is placed in P. subsect. Polyactis and compared with P. microphyllus and P. stannardii, which have their pollen grains and seeds also herein described for the first time.

scholarly journals Leaf anatomy and its contribution to the systematics of Aechmea subgenus Macrochordion (de Vriese) Baker (Bromeliaceae)

2012 ◽  
Vol 84 (4) ◽  
pp. 961-971 ◽  
Author(s):  
Ana Paula G. de Faria ◽  
Ana Claudia M. Vieira ◽  
Tânia Wendt
Keyword(s):  
Leaf Anatomy ◽  
Epidermal Cells ◽  
External Morphology ◽  
Vascular Bundles ◽  
Valuable Data ◽  
Anatomical Adaptations ◽  
Peltate Trichomes ◽  
Air Channels

The leaf anatomy of the species Aechmea subgenus Macrochordion was analyzed to obtain valuable data on their taxonomic delimitation and to identify anatomical adaptations to their respective habitats and habits. All leaves of these species are hypostomatic, and present: peltate trichomes on both surfaces; stomata sunk in epidermal depressions; small epidermal cells with thick walls and inclusions of silica bodies; a mechanical hypodermis; an aquiferous parenchyma; chlorenchyma with fibrous clusters and air channels; and vascular bundles surrounded by a parenchymatic sheath and a cap of fibers. The results are evaluated within an adaptive and taxonomic context. Variations in hypodermic thickening, amount of water parenchyma, position of the air channels and shape of the cells filling the air channels are useful for delimiting groups of species, strengthening the relationships suggested by their external morphology.

scholarly journals Structure of floral nectaries in Aesculus hippocastanum L.

2017 ◽  
Vol 76 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Elżbieta Weryszko-Chmielewska ◽  
Mirosława Chwil
Keyword(s):  
Electron Microscopy ◽  
Morphological Diversity ◽  
Aesculus Hippocastanum ◽  
Vascular Bundles ◽  
Fluorescence And Electron Microscopy ◽  
The Family ◽  
Floral Nectaries ◽  
Light Fluorescence ◽  
Parenchymal Cells ◽  
First Time

Abstract Representatives of the family Sapindaceae exhibit high morphological diversity of the nectary structure. The present paper shows for the first time the results of micromorphological, anatomical, and ultrastructural analyses of floral nectaries in Aesculus hippocastanum. We have also described the forage and signal attractants of these flowers, which are important for the ecology of pollination. Using light, fluorescence, and electron microscopy, we demonstrated that the A. hippocastanum nectary forming a lobed disc is histologically differentiated into the epidermis with stomata, nectariferous parenchyma, subglandular parenchyma, and vascular bundles reaching the basal part of the nectariferous parenchyma. The use of histochemical assays revealed the presence of insoluble polysaccharides, lipids, terpenoids, and polyphenols including coumarins in the nectary tissues. Nectar is exuded onto the nectary surface via stomata and the permeable cuticle. As indicated by the observation of the ultrastructure of the nectary cells, transport of pre-nectar into parenchymal cells may proceed via the symplast and apoplast. We have also demonstrated that nectar transfer outside the protoplasts of parenchymal cells has a character of granulocrine secretion. A. hippocastanum flowers produce nectar abundantly; one flower secreted on average 2.64 mg of nectar and the concentration of sugars in the nectar was 33%.

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