scholarly journals Spore morphology of Taenitis, Syngramma, and Austrogramme species (Pteridoideae, Pteridaceae) from South-Eastern Asia and Oceania. II

Turczaninowia ◽  
2021 ◽  
Vol 24 (3) ◽  
pp. 36-51
Author(s):  
Alexey V. Vaganov ◽  
Irina I. Gureyeva ◽  
Alexander I. Shmakov ◽  
Alexander A. Kuznetsov ◽  
Roman S. Romanets

This paper continues consideration of the spores of three paleotropical fern genera – Taenitis, Syngramma, and Austrogramme (Pteridoideae, Pteridaceae) from South-Eastern Asia and Oceania. At the second stage, we carried out a comparative scanning electron microscopy study of spores of three species of Austrogramme, four species of Syngramma, and six species of Taenitis and added information about previously studied spores of seven species of these genera. Spores of all examined species are trilete, tetrahedral or tetrahedral-globose with convex to hemispherical distal side and plane, convex or conical proximal side. The spores of Austrogramme species are the smallest, simplest in ornamentation and similar to each other. Sculpture of the proximal and distal sides are microverrucate, the surface of the spores is covered by granular deposits. Spores of most Syngrammaspecies are very similar to spores of Austrogramme species in shape and surface sculpture: their distal and proximal surfaces are microverrucate, whereas the spores of S. borneensis and S. cartilagidens have the low-tuberculate sculpture. Spores of Taenitis species are very different from the spores of Austrogramme and Syngramma. Seven of nine studied species have spores with well-expressed cingulum (T. blechnoides, T. cordata, T. diversifolia, T. interrupta, T. luzonica, T. obtusa, and T. requiniana), three species (T. cordata, T. hookeri, and T. pinnata) have spores with prominent laesural ridges. The spores have well-expressed ornamentation – tuberculate, baculate, rugate, tuberculate-rugate. The most conspicuous character of the ornamentation of spore surfaces is the presence of rodlets associated with sculpture elements. The densest rodlets are characteristic of Taenitis diversifolia, T. luzonica, T. obtusa, and T. requiniana. Spore size (equatorial diameter) ranges on average between 22 μm and 37 μm in Austrogramme, between 27 μm and 41 μm in Syngramma, and between 26 and 51 μm in Taenitis species.

2017 ◽  
Vol 7 (4) ◽  
pp. 231-233
Author(s):  
A. V. Vaganov ◽  
I. I. Gureyeva ◽  
A. A. Kuznetsov ◽  
R. S. Romanets

A comparative study of spores of two species of Vaginularia (Vittarioideae, Pteridaceae) from South-Eastern – Vaginularia paradoxa (Fée) Mett. ex Miq. and V. trichoidea Fée – was performed by the method of scanning electronic microscopy (SEM). Spores are tetrahedral, trilete; they are very similar to each other in smooth surface and relatively narrow laesura arms. Differences between species are in shape of spores in proximal position (triangular with narrowly-rounded corners and concave sides in V. paradoxa and triangular with broadly-rounded corners and slightly concave sides in V. trichoidea), in length of laesura arms relative to the radius of the spore (laesura arms are about 0.75 of spore radius in V. paradoxa, and riches corners of spore in V. trichoidea) and in size of spore (spore of V. paradoxa are about 1.5 times more in equatorial diameter and 1.7 times more in polar axis length).


Author(s):  
Julie A. Martini ◽  
Robert H. Doremus

Tracy and Doremus have demonstrated chemical bonding between bone and hydroxylapatite with transmission electron microscopy. Now researchers ponder how to improve upon this bond in turn improving the life expectancy and biocompatibility of implantable orthopedic devices.This report focuses on a study of the- chemical influences on the interfacial integrity and strength. Pure hydroxylapatite (HAP), magnesium doped HAP, strontium doped HAP, bioglass and medical grade titanium cylinders were implanted into the tibial cortices of New Zealand white rabbits. After 12 weeks, the implants were retrieved for a scanning electron microscopy study coupled with energy dispersive spectroscopy.Following sacrifice and careful retrieval, the samples were dehydrated through a graduated series starting with 50% ethanol and continuing through 60, 70, 80, 90, 95, and 100% ethanol over a period of two days. The samples were embedded in LR White. Again a graduated series was used with solutions of 50, 75 and 100% LR White diluted in ethanol.


2014 ◽  
Vol 48 ◽  
pp. 57-65 ◽  
Author(s):  
S. I. Genkal ◽  
M. I. Jarushina

A rare species Sellaphora hustedtii, which is also new for the flora of Russia, has been found in waterbodies of the Messoyakha River basin (south-western part of the Gydan Peninsula, Western Siberia). The scanning electron microscopy study revealed variability of the main quantitative and qualitative diagnostic features of the species (length and width of the valve, number of striae and areolae in 10 μm, shape of the valve and structure of the raphe). New data on the ecology and distribution of the species allowed us to specify its diagnosis.


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