Seed morphology of 12 taxa of the genus Thalictrum L. (Thalictroideae, Ranunculaceae) and its systematic implication

Phytotaxa ◽  
2016 ◽  
Vol 283 (3) ◽  
pp. 271 ◽  
Author(s):  
BALKRISHNA GHIMIRE ◽  
HAYAN LEE ◽  
GO EUN CHOI ◽  
MI JIN JEONG ◽  
GANG UK SUH ◽  
...  

The seed morphology and anatomy of 12 species, representing five sections of Thalictrum, were investigated by scanning electron microscopy (SEM) and light microscopy (LM) to evaluate seed features for use in systematic analysis. Considerable differences were observed in seed surface micromorphology and seed coat characteristics both among and within sections of the genus. MANOVA, MDA, and cluster analysis were used to unravel the morphology of seeds among the species. The characteristic seed features for species were found to be seed shape, size, testa thickness, exotestal cells and seed surface sculpture. The results indicated that the most prevalent seed coat sculpture among the studied species was reticulate and some species were reticulate at the margin and rugose in the center. Seed surface was without ornamentation and epidermal cells were mostly polygonal, rectangular or irregularly shaped. The testa thickness varied from two to six cell layers, and the exotesta was well characterized and rectangular to tangentially elongate in most of the species, except T. simplex and T. uchiyamae in which exotesta was poorly represented. It has been observed that species with a non-reticulate or poorly developed reticulate surface sculpture have a less protected seed coat and vice versa. The results of this study indicated that seed morphological features do not, in general, provide strong support to the sectional division of the genus, but that species within sections shared some comparable seed features.

Phytotaxa ◽  
2013 ◽  
Vol 150 (1) ◽  
pp. 41 ◽  
Author(s):  
Somayeh Ghaempanah ◽  
Hamid Ejtehadi ◽  
Jamil Vaezi ◽  
Mohammad Farsi

In order to examine the systematic application of seed-coat characters in Erysimum (Brassicaceae) distributed in Northeast of Iran (Khorassan provinces), the seeds of nine species (14 populations) were examined using the light microscope (LM) and the scanning electron microscope (SEM). According to results of the LM, diagnostic characters at the specific level are seed shape, wing width, epidermal cell-wall shape, and seed-surface sculpture. The SEM investigation at high magnifications reveals that seven types of seed-surface sculpture pattern are distinguishable, including 1) reticulate, the basic type; 2) ocellate; 3) papillate; 4) reticulate-papillate; 5) scalariform; 6) ribbed; and 7) reticulate-ocellate. The seed coat typically consists of four layers, including the epidermis layer, the subepidermis layer, the sclerotic (or palisade) layer, and the parenchymatous layer. Some of the layers may be absent in some species. Finally, an identification key to the investigated taxa is provided based on the seed-coat characters used in this research.


2018 ◽  
Vol 22 (03) ◽  
pp. 69-71
Author(s):  
Binderya G ◽  
Tumenjargal D

The paper presents the results of the study on seed morphology and anatomy of Allium anisopodium Ldb. The seed shape is elliptic, glossy-black in color. The seed surface is scaly and its hilum appears in white color. The seed size is 1.7-2.1 mm long, 1.2-1.4 wide, 0.5-2.1 mm in thick and one thousand seed weight is 1.9 g. The anatomical structure is endospermic one cotyledons seed type. The seed coat thin and cotyledon is emphasized apparently from longitudinal section. The embryo is curved, coiled and black colored embryonic roots are relatively thick. The endosperm is surrounded by seed coat moreover between the cotyledon and embryo.


2019 ◽  
Vol 26 (2) ◽  
pp. 315-324
Author(s):  
Soghra Ramzi ◽  
Shahryar Saedi-Mehrvarz

Seed morphology of 12 Iranian endemic and subendemic species of Veronica was studied using scanning electron microscope (SEM). Seven qualitative and quantitative characters were measured using SEM micrographs and stereomicroscopy. The seed shape of most species is ovate and plano-convex. The size of seeds ranges from 1.25 x 0.75 mm in V. khorassanica to 2.5 x 1.75 mm in V. viscosa Boiss. The ornamentation of seed coat is reticulate-verrucate in V. khorassanica, V. czerniakowskiana, V. mazanderanae and V. rubrifolia, reticulate-rugate in V. acrotheca, V. aucheri, V. viscosa and V. intercedens, rugose in V. microcarpa, V. chionantha and V. rechingeri, and reticulate-porate in V. gaubae. The testa cells are polygonal in ten species and irregular in two species. Micromorphological characters of seeds are useful in specific and subspecific delimitations of Iranian Veronica.


2014 ◽  
Vol 35 (1) ◽  
pp. 15-18
Author(s):  
Piotr Szkudlarz

Abstract Hypericum elegans is a rare perennial distributed primarily in Central and Eastern Europe. Seed morphology and anatomy in H. elegans was studied on the basis of a seed sample from its only locality in Poland. Scanning electron microscopy revealed that the seed coat of mature seeds is composed basically of 3 cell layers: epidermal, subepidermal and sclerenchymatic. They are documented graphically here.


Phytotaxa ◽  
2018 ◽  
Vol 336 (3) ◽  
pp. 263
Author(s):  
İLKER GENÇ ◽  
ŞÜKRAN KÜLTÜR

A comprehensive study based on seed morphology of perennial Euphorbia (Euphorbiaceae) sect. Pithyusa species occurring in Turkey is presented. A total of 14 species were studied. Seed characteristics were examined using scanning electron microscopy (SEM) as well as dissecting light microscopy. Significant features are: seed size, seed shape, shape of caruncle and seed surface ornamentation. Three different seed surface types (smooth, pitted, and wrinkled) were observed. Four main seed shapes (ovoid, oblong, quadrangular, and globose), as well as seven types of seed coat ornamentation (reticulate-areolate, areolate, alveolate, falsifoveate, pusticulate, colliculate and smooth) were found. The number of testa cells per 100 µm2 and also its range, from 8–12 to 57–63, are given.


VAVILOVIA ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 5-28
Author(s):  
N. B. Alexeeva

The genus Iris in Russia is represented by 41 species. Four species are endemic, 11 are included in the Red Data Book of the Russian Federation and 30 have different regional conservation status. The presented results of the study of the morphology of seeds and of seed coat surface morphology in 40 species from the genus Iris growing in Russia were obtained mainly using light and scanning electron microscopy. Seed shape is round, ovate, oblong or pear‑shaped, with the exception for I. psammocola, in which it is club‑shaped. The smallest seeds in the studied species belong to I. ruthenica and I. uniflora. Morphometric data lead to interesting conclusions regarding the taxonomic relations between some species. For example, the species currently considered as synonyms, e.g., I. biglumis and I. pallasii in I. lactea, and I. maackii in I. pseudacorus, are found different concerning seed morphology. On the other hand, the taxonomically well distinct species such as I. halophila and I. pseudonotha share similar seed morphology. A study of the morphological characteristics of the seed coat surface in 40 species of the genus Iris made it possible to compile an atlas for determining species in the genus Iris in Russia.


2019 ◽  
Vol 126 (1) ◽  
pp. 39-59
Author(s):  
Ulla Neumann ◽  
Angela Hay

Abstract Background and Aims Seeds are dispersed by explosive coiling of the fruit valves in Cardamine hirsuta. This rapid coiling launches the small seeds on ballistic trajectories to spread over a 2 m radius around the parent plant. The seed surface interacts with both the coiling fruit valve during launch and subsequently with the air during flight. We aim to identify features of the seed surface that may contribute to these interactions by characterizing seed coat differentiation. Methods Differentiation of the outermost seed coat layers from the outer integuments of the ovule involves dramatic cellular changes that we characterize in detail at the light and electron microscopical level including immunofluorescence and immunogold labelling. Key Results We found that the two outer integument (oi) layers of the seed coat contributed differently to the topography of the seed surface in the explosively dispersed seeds of C. hirsuta vs. the related species Arabidopsis thaliana where seed dispersal is non-explosive. The surface of A. thaliana seeds is shaped by the columella and the anticlinal cell walls of the epidermal oi2 layer. In contrast, the surface of C. hirsuta seeds is shaped by a network of prominent ridges formed by the anticlinal walls of asymmetrically thickened cells of the sub-epidermal oi1 layer, especially at the seed margin. Both the oi2 and oi1 cell layers in C. hirsuta seeds are characterized by specialized, pectin-rich cell walls that are deposited asymmetrically in the cell. Conclusions The two outermost seed coat layers in C. hirsuta have distinct properties: the sub-epidermal oi1 layer determines the topography of the seed surface, while the epidermal oi2 layer accumulates mucilage. These properties are influenced by polar deposition of distinct pectin polysaccharides in the cell wall. Although the ridged seed surface formed by oi1 cell walls is associated with ballistic dispersal in C. hirsuta, it is not restricted to explosively dispersed seeds in the Brassicaceae.


2015 ◽  
Vol 33 (4) ◽  
pp. 699-705 ◽  
Author(s):  
M. ÖZKAN ◽  
E. AKTOKLU ◽  
C. ÖZDEMIR

ABSTRACT The seed (nutlet) morphology of four Onobrychis Miller (Fabaceae: subfamily Papilionoideae, Section Hymenobrychis DC.) taxa from Turkey, including three endemic taxa, was examined using scanning electron microscopy. Onobrychis tournefortii, O. galegifolia, O. cappadocica, O. albiflora. The seed examined exhibited variation in size, shape, colour, and surface sculpturing. Seed size ranged between 4.0-5.2 mm length and 2.0-3.6 mm width. Observed shapes included; ellipticus anguste asymmtricus reniformis, Ovatus anguste asymmetricus reniformis and ellipticus reniformis. Seed surface sculpturing revealed two distinct types: reticulate and rugulate. Species of Onobrychisare generally similar and confused with those of Hedysarumduring the identification process. Seed surface micromorphology can suggest taxonomical diagnostic characters for distinguishing species. Many of these characteristics are diagnostic at both the generic and specific levels.


2020 ◽  
Vol 45 (3) ◽  
pp. 478-482
Author(s):  
Steven R. Manchester

Abstract—The type material on which the fossil genus name Ampelocissites was established in 1929 has been reexamined with the aid of X-ray micro-computed tomography (μ-CT) scanning and compared with seeds of extant taxa to assess the relationships of these fossils within the grape family, Vitaceae. The specimens were collected from a sandstone of late Paleocene or early Eocene age. Although originally inferred by Berry to be intermediate in morphology between Ampelocissus and Vitis, the newly revealed details of seed morphology indicate that these seeds represent instead the Ampelopsis clade. Digital cross sections show that the seed coat maintains its thickness over the external surfaces, but diminishes quickly in the ventral infolds. This feature, along with the elliptical chalaza and lack of an apical groove, indicate that Ampelocissites lytlensis Berry probably represents Ampelopsis or Nekemias (rather than Ampelocissus or Vitis) and that the generic name Ampelocissites may be useful for fossil seeds with morphology consistent with the Ampelopsis clade that lack sufficient characters to specify placement within one of these extant genera.


2007 ◽  
Vol 55 (6) ◽  
pp. 618 ◽  
Author(s):  
Kim N. Hamilton ◽  
Sarah E. Ashmore ◽  
Rod A. Drew ◽  
Hugh W. Pritchard

Combinational traits of seed size and seed-coat hardness in Citrus garrawayi (F.M.Bailey) (syn. of Microcitrus garrowayi) were investigated as markers for estimation of seed morphological and physiological maturity. Seed size (length) and coat hardness correlated well with changes in seed coat and embryo morphological development, dry-weight accumulation, decreases in moisture content and a significant increase in germinability. Seed moisture content decreased from 82 ± 1% in immature seeds to 40 ± 1% at seed maturation. The outer integument of immature seeds consisted of thin-walled epidermal fibres from which outgrowths of emerging protrusions were observed. In comparison, mature seed coats were characterised by the thickening of the cell walls of the epidermal fibres from which arose numerous protrusions covered by an extensive mucilage layer. Immature seeds, with incomplete embryo and seed-coat histodiffereniation, had a low mean germination percentage of 4 ± 4%. Premature seeds, with a differentiated embryonic axis, were capable of much higher levels of germination (51 ± 10%) before the attainment of mass maturity. Mature seeds, with the most well differentiated embryonic axis and maximum mean dry weight, had the significantly highest level of germination (88 ± 3%).


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