scholarly journals Introduction of DNA-based Methods to Agriculture Through Molecular Taxonomic Examination of Poa Species

2005 ◽  
pp. 139-142
Author(s):  
Ákos Zubor ◽  
Zsuzsa K. Szabó ◽  
Antónia Nyakas ◽  
Mária Papp ◽  
József Prokisch

biological methods, one among them is AFLP that is well applicable for taxonomic research. Bluegrass species, that are important components of meadow associations, thus their thorough knowledge is necessary in maintaining biodiversity, were examined with bringing this method to perfection.Taxonomic relationship of the members of Poa pratensis aggregation is a controversial issue. Present study aimes to identify the members of this group, with a developed AFLP method through molecular taxonomic examination of Poa species in meadows nearby Debrecen, revealing their genetical distances. Species of the aggregation show a great genetic variability, but their genetic proximity approves the use of the term aggregation. Results established wider geographical investigation of three species of the aggregation. The distinctness of the species based on their morphological features was confirmed according to their genetical basis as well. The method overall turned out to be appropriate for the taxonomic research of bluegrass species like Poa pratensis and its aggregation.

2015 ◽  
Vol 43 (4) ◽  
pp. 567-578 ◽  
Author(s):  
V. Muthusamy ◽  
F. Hossain ◽  
N. Thirunavukkarasu ◽  
S. Saha ◽  
P. K. Agrawal ◽  
...  

2003 ◽  
Vol 99 (1) ◽  
pp. 151-155 ◽  
Author(s):  
Giovani Vandewalle ◽  
Emile Beuls ◽  
Linda Vanormelingen ◽  
Marjan Vandersteen

Object. Knowledge of normal variations in ventricular morphological features is important in endoscopic neurosurgery. Classically, two elevations are described on the medial wall of the occipital horn of the lateral ventricle: an upper bulb and a lower calcar avis. Nevertheless, a third, as yet unreported elevation may be present at the junction of the medial wall and the floor of the occipital horn. The authors report the frequency with which this third elevation was found in a series of cadaveric brains. Methods. The medial wall of the occipital horn of the lateral ventricle was studied in the three orthogonal planes in 45 formalin-fixed cadaveric hemispheres. The underlying structures responsible for the observed intraventricular prominences were exposed by microdissection. A third elevation was present, lying ventrorostral to the calcar avis, in seven (47%) of the 15 single hemispheres, and bilaterally in six (40%) of the 15 whole brains. After microdissection, a fiber bundle from the splenium of the corpus callosum was seen emerging in the occipital horn at the angle between the tail of the hippocampus and the bulb of the occipital horn. The most rostral fibers fanned out inferolaterally along the floor of the collateral trigone. The larger, posterior part protruded into the medial wall along the ventral border of the calcar avis as far as the tip of the occipital horn. Conclusions. Besides its importance as a variation of normal ventricular morphological features, the close relationship of this accessory intraventricular prominence to the tail of the hippocampus should be kept in mind when intervening neurosurgically so that damage to the underlying commissural fibers can be avoided.


2020 ◽  
Author(s):  
James B. Stribling ◽  
Erik W. Leppo

AbstractBiological nomenclature is the entry point to a wealth of information related to or associated with living entities. When applied accurately and consistently, communication between and among researchers and investigators is enhanced, leading to advancements in understanding and progress in research programs. Based on freshwater benthic macroinvertebrate taxonomic identifications, inter-laboratory comparisons of >900 samples taken from rivers, streams, and lakes across the U.S., including the Great Lakes, provided data on taxon-specific error rates. Using the error rates in combination with frequency of observation (FREQ; as a surrogate for rarity), six uncertainty/frequency classes (UFC) are proposed for approximately 1,000 taxa. The UFC, error rates, FREQ each are potentially useful for additional analyses related to interpreting biological assessment results and/or stressor response relationships, as weighting factors for various aspects of ecological condition or biodiversity analyses and helping set direction for taxonomic research and refining identification tools.


HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1036D-1037
Author(s):  
Zhanao Deng ◽  
Jinguo Hu ◽  
Fahrettin Goktepe ◽  
Brady A. Vick ◽  
Brent K. Harbaugh

Cultivated caladiums are valued for their bright colorful leaves and are widely used in containers and landscapes. More than 1500 named cultivars have been introduced during the past 150 years, yet currently only about 100 cultivars are in commercial propagation in Florida. Caladium tubers produced in Florida account for 95% of the world supplies. Loss of caladium germplasm or genetic diversity has been a concern to future improvement of this plant. In addition, the relationship among the available cultivars, particularly those of close resemblance, has been lacking. This study was conducted to assess the genetic variability and relationship in commercial cultivars and species accessions. Fifty-seven major cultivars and 15 caladium species accessions were analyzed using the target region amplification polymorphism marker technique. This marker system does not involve DNA restriction or adaptor linking, but shares the same high throughput and reliability with the amplified fragment length polymorphism system (AFLP). Eight primer combinations amplified 379 scorable DNA fragments among the caladium samples. A high level of polymorphism was detected among the species accessions as well as among cultivars. These markers allowed differentiation of all the cultivars tested, including those hardly distinguishable morphologically. Clustering analysis based on these DNA fingerprints separated the cultivars into five clusters and Caladium lindenii far from other caladium species. The availability of this information will be very valuable for identifying and maintaining the core germplasm resources and will aid in selecting breeding parents for further improvement.


PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0241933
Author(s):  
James B. Stribling ◽  
Erik W. Leppo

Biological nomenclature is the entry point to a wealth of information related to or associated with living entities. When applied accurately and consistently, communication between and among researchers and investigators is enhanced, leading to advancements in understanding and progress in research programs. Based on freshwater benthic macroinvertebrate taxonomic identifications, inter-laboratory comparisons of >900 samples taken from rivers, streams, and lakes across the U.S., including the Great Lakes, provided data on taxon-specific error rates. Using the error rates in combination with frequency of observation (FREQ; as a surrogate for rarity), six uncertainty/frequency classes (UFC) are proposed for approximately 1,000 taxa. The UFC, error rates, FREQ each are potentially useful for additional analyses related to interpreting biological assessment results and/or stressor response relationships, as weighting factors for various aspects of ecological condition or biodiversity analyses and helping set direction for taxonomic research and refining identification tools.


2017 ◽  
Vol 90 (1) ◽  
pp. 7-14 ◽  
Author(s):  
Ann B. Butler

The hippocampus was first named in mammals based on the appearance of its gross morphological features, one end of it being fancied to resemble the head of a horse and the rest of it a silkworm, or caterpillar. A hippocampus, occupying the most medial part of the telencephalic pallium, has subsequently been identified in diverse nonmammalian taxa, but in which the “horse-caterpillar” morphology is lacking. While some strikingly similar functional similarities have been identified, questions of its homology (“sameness”) across these taxa and about the very fundamental relationship of structure to function in central nervous system structures remain open. The hippocampal formation of amniotes participates in allocentric (external landmark) spatial navigation, memory, and attention to novel stimuli, and these functions generally are shared across amniotes despite variation in its morphological features. Substantially greater deviation in its morphology occurs in anamniotes, including amphibians and ray-finned fishes (actinopterygians), but its functions of allocentric spatial navigation and/or memory have been found to be preserved by studies in these taxa. Its shared functional roles cannot be used as evidence of structural homology, but given that other criteria indicate homology of the medial pallial derivative across these clades, the similar functions themselves may be regarded as homologous functions if they are based on the same cellular mechanisms and connections. The question arises as to whether the similar functions are performed by as yet undiscovered, shared morphological features or by different features that accomplish the same results via different mechanisms of neural function.


2008 ◽  
Vol 70 (9) ◽  
pp. 953-959 ◽  
Author(s):  
Barbara Phillips-Bute ◽  
Joseph P. Mathew ◽  
James A. Blumenthal ◽  
Richard W. Morris ◽  
Mihai V. Podgoreanu ◽  
...  

2005 ◽  
pp. 35-39
Author(s):  
Zsuzsa K. Szabó

The Poa pratensis L. and the Poa angustifolia L. are close relative species whose morphological features vary greatly. Our goal was to examine how the inividuals from different soil types of these species differ statistically from one another, whether the morphological features of the variant species differ significantly, and whether they keep their specific features in dissimilar habitats.The quantitative features of the populations developing on distinct soil types wich are statistically separate provide for the different phenotype forming effect of the soil types as variant habitats. There is connection between the soil types and the measurement of the ramets on every soil types. The morphometric values of P. pratensis – that are bigger in all habitats – show that this species genetically widely adapted. Significantly different morphological features were found, but because of the high environmental dependence of the morphological features and of the significantly different characteristics which reveal several overlaps between the two species, these characteristics cannot be considered as reliable identification keys.


2005 ◽  
Vol 25 (03) ◽  
pp. 267-271 ◽  
Author(s):  
G. Nowak ◽  
M. Lopez

SummaryThe structure-activity relationship of dipetalogastin II, the strongest thrombin inhibitor isolated and cloned from the bug Dipetalogaster maximus, was examined by introducing gradual changes into the molecule by means of molecular biological methods. The effect upon its inhibition equilibrium constant was determined after each change by a chromogenic assay. This structural information was fundamental to design new dipetalogastin II-derived inhibitors.Our results suggested that the acidic sequence DEHDHDFEDT corresponding to amino acid residues 49 to 58 of dipetalogastin II reacts with the anion binding exosite (ABE) 1 of thrombin. Based on this finding, we constructed a chimeric molecule consisting of the active site blocking segment of dipetalogastin II (amino acid residues 1 to 48) and the ABE 1 blocking segment of hirudin. This construct showed better thrombin inhibitory activity than both separated segments only after the introduction of a glycine linker between both blocking segments. We thus obtained a thrombin inhibitor called dipetarudin with an inhibition equilibrium constant comparable to that of dipetalogastin II and a molecular mass below that of dipetalogastin.


2017 ◽  
Vol 54 ◽  
pp. 156-161 ◽  
Author(s):  
K. I. Timchy ◽  
V. T. Smetanin ◽  
O. I. Sidashenko

Introduction. Intensification of various aspects of modern agricultural production, based on the use of a large number of mineral fertilizers and chemical means of plant and animal protection, actualizes the development and mastering of natural-like methods for restoring the quality of soils and bottom deposits of inland water bodies. The goal is their successful use in cultivating cultivated plants and conducting remediation measures. One such approach is vermiculturing – breeding of earthworms of the family Lumbricidae, for biotransformation of depleted soils and organic wastes in order to obtain biohumus. Relevance. Earthworms differ significantly in biological characteristics from animals, traditionally bred in agriculture. When working with them, a selection problem arises to assess their phenotypes – it is difficult to identify individuals and assess their performance. In this regard, the main task of effective selection becomes more complicated. Today in scientific sources on the study of the genetic structure of earthworms natural populations, their karyotypes and morphological features are not few data [3]. But the development of vermiculture, based on breeding and industrial use for biotransformation of earthworms, requires a clear species identification of cultural lines of invertebrate animals of the family Lumbricidae. Research objective. The aim of the study was to investigate the morphological and cytogenetic features of the Eisenia worms population that is being forms. Materials and methods. While forming of the new population, the worms that were purchased by the Department of Biotechnology of the UGHTU in the association "Bioconversion" and previously described as E. foetida were used. Of the array of these animals, 6 worms were selected that became the founders of the new population. After increasing the number of up to 300 animals, we formed groups of 20 individuals, each group irradiated with a laser of the LGN-208b type With a power of 1 mW, a wavelength of 633 nm, a beam diameter of 14 mm, various exposures in time from 5 to 30 min. The control was not irradiated. Irradiated animals were bred in separate groups and studied morphological, biochemical and cytogenetic features. Morphological study of the species affiliation was carried out that was determined and compared with the descriptions of these species given in the works of foreign taxonomy [5]. The intensity of the pigmentation of the integument of the body was determined in animals. All further morpho-metric studies were carried out on worms fixed in 75% ethanol. By the method of microscopy, parameters such as length and diameter of the body, total number of segments, location of the segments of the girdle, pubertal ridges and the first dorsal pore, type of setae were analyzed. Karyological analysis was performed with worms selected at the time of highest sexual activity. Preparations were prepared from the tissue of the seminal sacks by the method previously successfully used to study karyotypes of lumbricids [6]. The worms were injected with 0.1% solution of colchicine into the pre-lobe zone for 19 hours. 20 min to the autopsy. The animals were immobilized in 75% ethanol solution and digested along the median spinal line. Removed spermatic bags hypotone 50 min. in the distillate and fixed in three steps in a mixture of acetic acid and ethanol in a ratio of 1:3. Chromosome preparations were made by imprinting. Genetic markings were performed by electrophoresis in a 7.5% polyacrylamide gel Tris-EDTA • Na2-borate system with pH = 8.5 [7] 1 hour 20 minutes at a voltage of 200 V and a current strength of 140–mA. Extract of enzymes and proteins was obtained by grinding the final segments of the body with a size of 5–10 mm in the distillate in the ratio 1:1. After switching of the electric current, the gel was treated with a solution containing a special substrate that specifically reacts with the enzyme under study, forming spots corresponding to the spectra of the enzymes on the gels. The genotype of the individual according to the locus encoding the enzyme being studied is determined by the nature of the distribution of the spots on the gel [8]. Results of the research. The carried out researches have shown that the groups of animals under study belong to the species E. foetida, and by other attributes to the species E. venetta, which caused the problem of the species affiliation of the earthworm array when working to form a new population. Thus, the morphological indices studied have revealed that animals for all morphological features refer to the species Eisenia foetida. During the study of cytogenetic, it was found that the karyotype of the animals was 36 chromosomes but it should be 22. Just kind of Eisenia foetida is composed of 22 chromosomes and karyotypes of other species of the genus Eisenia have 36 chromosomes. Therefore, biochemical gene marking was carried out on enzyme systems, in particular nonspecific esterases. Nonspecific esterases of different species of the genus Eisenia differ in molecular weight. Esterаs of E. foetida have a lower mass than esterases of E. veneta. Our studies showed that in the place of the locus of spectra of nonspecific esterases, the individuals under study belong to the species E. veneta. Nonspecific esterases of different species of the genus Eisenia differ in molecular weight. Esterases E. foetida have a lower mass than E. veneta esterase. Our studies have shown that individuals at the locus of spectra of non-specific esterases belong to the species E. veneta. Conclusions The research may be a theoretical hypothesis for certain types of animal identification in vermiculture and creating biological diversity in its population. Despite the fact that it originates from 6 individuals obtained from a single array of animals, polymorphism by esterases showed a fairly high level of genetic variability in the forming line that indicates the reserve of its genetic variability and allows it to hope for its successful development in the future.


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