Karyotypic Studies in Artificial Hybrids of Solanum Sections Anarrhichomenum and Basarthrum (Solanaceae)

1999 ◽  
Vol 47 (1) ◽  
pp. 147 ◽  
Author(s):  
Laura Stiefkens ◽  
Gabriel Bernardello ◽  
Gregory J. Anderson
Keyword(s):  
Wild Species ◽  
Parental Species ◽  
Statistical Analyses ◽  
The Other ◽  
Genome Length ◽  
Mitotic Chromosomes ◽  
Chromosome Change ◽  
Centromere Position ◽  
Taxonomic Methods

Mitotic chromosomes of seven artificial hybrids fromSolanum L. sect.AnarrichomenumBitter &Basarthrum (Bitter) Bitter were studied(S. caripense Humb. & Bonpl. ex Dunal ×S. basendopogon Bitter,S. caripense × S. muricatumAiton, S. muricatum ×S. basendopogon, S. muricatum× S. caripense,S. muricatum× S. cochoae G.J. Anderson & Bernardello, S. sodiroi Bitter ×S. brevifolium Humb. & Bonpl., andS. sodiroi ×S. caripense).All are wild species except S. muricatum, which is knownonly as a domesticate (‘pepino dulce’). All hybrids were diploidwith 2n = 24. We compare the karyotypes ofparental species and their hybrids to understand chromosome change as acomponent of the evolution of these sections. Statistical analyses ofchromosomes, genome length and centromere position yielded estimates ofkaryotype composition and asymmetry. Comparisons were made by means of ANOVAsand numerical taxonomic methods. Statistical comparisons among the hybridspooled showed much karyotypic similarity among them. Karyotypes of theparental species revealed sharper differences among them. The karyotypes ofthe hybrids except for one combination were not intermediate. In general, thekaryotypes of the hybrids showed relatedness to the karyotype of one parentalspecies. The hybrids involving S. muricatum havechromosomal features closer to it than to the other parental species. Previousstudies showed S. caripense among the wild species to bemost similar to S. muricatum and, as expected, therewere the fewest differences between these species and the hybrids betweenthem. The karyotype of S. sodiroi×S. brevifolium is the most different from the karyotypeof either of its parental species.

Taxonomy and the Direct Historical Approach

1942 ◽  
Vol 8 (2) ◽  
pp. 170-172 ◽  
Author(s):  
W. C. McKern
Keyword(s):  
The Other ◽  
Historical Approach ◽  
Taxonomic Methods

It seems apparent from Julian Steward's latest statement on The Direct Historical Approach to Archaeology that he still conceives of a basic conflict, or at least an inherent competition, between the direct historical and midwestern taxonomic methods, in spite of his initial statement to the contrary. He manifests a conviction that the latter is being overemphasized at the expense of the former. If his fears are well founded (and there are instances of malpractice which might be cited in support of his position), I should be among the first to join his crusade in defense of the direct historical “approach.” However, in that case, his criticism should be directed against the culprits who are misusing methods rather than against any given method itself. Instead, Steward adopts the tone of one who sets out to compare the respective values of two conflicting methods, to the glorification of one and the general degradation of the other.

scholarly journals Analysis of genetic relationships of genotypes of the genus Rosa L. from the collection of Nikita Botanical Gardens using ISSR and IRAP DNA markers

2020 ◽  
Vol 24 (5) ◽  
pp. 474-480
Author(s):  
I. I. Suprun ◽  
S. A. Plugatar ◽  
I. V. Stepanov ◽  
T. S. Naumenko
Keyword(s):  
Genetic Diversity ◽  
Bayesian Methods ◽  
Dna Markers ◽  
Wild Species ◽  
Genetic Similarity ◽  
Genetic Relationships ◽  
Issr Markers ◽  
The Other ◽  
Clustering Methods ◽  
Botanical Gardens

In connection with the development of breeding and the creation of new plant varieties, the problem of their genotyping and identification is becoming increasingly important, therefore the use of molecular methods to identify genetic originality and assess plant genetic diversity appears to be relevant. As part of the work performed, informative ISSR and IRAP DNA markers promising for the study of genetic diversity of the Rosa L. genus were sought and applied to analysis of genetic relationships among 26 accessions of the genus Rosa L. from the gene pool collection of Nikita Botanical Gardens. They included 18 cultivated varieties and 8 accessions of wild species. The species sample included representatives of two subgenera, Rosa and Platyrhodon. The subgenus Platyrhodon was represented by one accession of the species R. roxburghii Tratt. Cultivated roses were represented by varieties of garden groups hybrid tea, floribunda, and grandiflora. The tested markers included 32 ISSRs and 13 IRAPs. Five ISSR markers (UBC 824, ASSR29, 3A21, UBC 864, and UBC 843) and three IRAPs (TDK 2R, Сass1, and Сass2) were chosen as the most promising. They were used for genotyping the studied sample of genotypes. In general, they appeared to be suitable for further use in studying the genetic diversity of the genus Rosa L. The numbers of polymorphic fragments ranged from 12 to 31, averaging 19.25 fragments per marker. For markers UBC 864 and UBC 843, unique fingerprints were identified in each accession studied. The genetic relationships of the studied species and varieties of roses analyzed by the UPGMA, PCoA, and Bayesian methods performed on the basis of IRAP and ISSR genotyping are consistent with their taxonomic positions. The genotype of the species R. roxburghii of the subgenus Platyrhodon was determined genetically as the most distant. According to clustering methods, the representative of the species R. bengalensis did not stand out from the group of cultivated varieties. When assessing the level of genetic similarity among the cultivated varieties of garden roses, the most genetically isolated varieties were ‘Flamingo’, ‘Queen Elizabeth’, and ‘Kordes Sondermeldung’; for most of the other varieties, groups of the greatest genetic similarity were identified. This assessment reflects general trends in phylogenetic relationships, both among the studied species of the genus and among cultivated varieties.

scholarly journals GENOME SIZE IN THREE SPECIES OF Glandularia AND THEIR HYBRIDS

2019 ◽  
Vol 30 (2) ◽  
pp. 47-54
Author(s):  
M.R. Ferrari ◽  
E.J. Greizerstein ◽  
L. Poggio
Keyword(s):  
Genome Size ◽  
Dna Content ◽  
High Frequency ◽  
Parental Species ◽  
The Other ◽  
F1 Hybrids ◽  
Homoeologous Pairing ◽  
The Relationship ◽  
Species Being ◽  
Homoeologous Chromosomes

In this work the relationship between genome size of Glandularia species and the meiotic configurations found in their hybrids are discussed. Glandularia incisa (Hook.) Tronc., growing in two localities of Corrientes and Córdoba provinces, Argentina, with different ecological conditions, showed inter-population variability of the 2C-value. The DNA content found in the Corrientes locality (2.41 pg) was higher than that obtained in the Córdoba locality (2.09 pg) which has more stressful environmental conditions than the former. These values are statistically different from those that were found in Glandularia pulchella (Sweet) Tronc. from Corrientes (1.43 pg) and in Glandularia perakii Cov. et Schn from Córdoba (1.47 pg). The DNA content of the diploid F1 hybrids, G. pulchella × G. incisa and G. perakii × G. incisa, differed statistically from the DNA content of the parental species, being intermediate between them. Differences in the frequency of pairing of homoeologous chromosomes were observed in the hybrids; these differences cannot be explained by differences in genome size since hybrids with similar DNA content differ significantly in their meiotic behavior. On the other hand, the differences in the DNA content between the parental species justify the presence of a high frequency of heteromorphic open and closed bivalents and univalents with different size in the hybrids. Key words: Intra-specific DNA content variability, homoeologous pairing, heteromorphic bivalents

Hybrids between Schistosoma mansoni and S. rodhaini: characterization by cercarial emergence rhythms

Parasitology ◽  
1989 ◽  
Vol 99 (2) ◽  
pp. 225-228 ◽  
Author(s):  
A. Thèron
Keyword(s):  
Schistosoma Mansoni ◽  
Parental Species ◽  
Genetic Determinism ◽  
The Other ◽  
Relative Importance ◽  
Emergence Rhythm ◽  
Cercarial Emergence

SummaryHybridization between Schistosoma mansoni, with a diurnal cercarial emergence rhythm and S. rodhaini, with a nocturnal cercarial shedding pattern leads to F1 and F2 generations, hybrid schistosomes whose chronobiological phenotype of cercariae is characterized by two unequal emergence peaks, one diurnal and the other nocturnal. The relative importance of diurnal and nocturnal peaks depends upon which S. mansoni strain (early or late) is used for the hybridization with S. rodhaini. The results are compared and discussed with those resulting from crosses between intraspecific sympatric and allopatric chronobiological variants (early and late) of S. mansoni. The genetic determinism of the cercarial emergence of schistosomes and the significant differences observed between cercarial shedding patterns of parental species and their hybrids allow the use of this behavioural marker in biological and genetical studies in schistosome populations.

Identification of two species of alpha motoneurons in cat's plantaris pool

1977 ◽  
Vol 40 (1) ◽  
pp. 16-25 ◽  
Author(s):  
D. A. Harris ◽  
E. Henneman
Keyword(s):  
Visual Inspection ◽  
Repetitive Stimulation ◽  
Ventral Root ◽  
Statistical Analyses ◽  
The Other ◽  
Small Samples ◽  
The Relationship ◽  
Decerebrate Cats ◽  
Two Populations ◽  
Stimulation Of

1. Single units of the plantaris pool were isolated in ventral root filaments of decerebrate cats and their critical firing levels (CFLs) were determined. Motoneurons of similar size, as judged by their CFLs and other criteria, were compared in firing rate (FR) during repetitive stimulation of the plantaris nerve. 2. Such units either differed very little or quite widely, suggesting that they were sampled randomly from two populations, one firing rapidly, the other slowly. The relationship between the two rates remained approximately constant, regardless of the intensity or rate of input the units received, as long as both of them discharged rhythmically. 3. In single experiments 10-15 of the smallest units in the pool (all with CFLs in the 0-8% range) were isolated and compared. Statistical analyses and visual inspection of these small samples again suggested the existence of two species of motoneurons. 4. Statistical analyses also indicated that the FRs of units in single experiments were not sampled from any one of a variety of parametric, single-modal distributions. This suggests that the data were sampled from a distribution having more than one mode, indicating the existence of separate populations or species of motoneurons among the small units of the pool (0-8% range of CFL). 5. Pooling of the normalized data from different experiments revealed a bimodal histogram, reinforcing the conclusion that there are two species of small alpha motoneurons in the plantaris pool.

scholarly journals Central Tokyo’s Low Response Rate to the 2015 Population Census and Its Related Factors

SAGE Open ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 215824402096308
Author(s):  
Tomoya Hanibuchi ◽  
Masakazu Yamauchi
Keyword(s):  
Online Survey ◽  
Response Rate ◽  
Statistical Analyses ◽  
The Other ◽  
Population Census ◽  
Single Family ◽  
Data Reliability ◽  
Middle Aged ◽  
Related Factors ◽  
Nationwide Study

Recently, there has been an increase in the number of “unreported” cases in the Population Census of Japan caused by nonresponses to the survey. Subsequently, this has led to data reliability challenges. In light of this problem, the factors related to the low response rate of the 2015 Population Census in the central Tokyo area are examined in the present study. An online survey was conducted among individuals residing in the three Special Wards of Tokyo to inquire about their responses (submitted or not submitted) to the previous census. The statistical analyses demonstrated that particularly in central Tokyo, middle-aged (35–49 years) people and those who did not own a single-family residence were more likely to be nonrespondents, while most of the other characteristics were similar to the results reported in a previous nationwide study. However, further studies are required to fully understand the high rates of unreported cases in central Tokyo.

Progenèse et Gémellité

1952 ◽  
Vol 1 (2) ◽  
pp. 159-169 ◽  
Author(s):  
R. Turpin ◽  
M. P. Schützenberger
Keyword(s):  
Statistical Analyses ◽  
The Other ◽  
Congenital Defects ◽  
Maternal Factors ◽  
Other Hand ◽  
Hereditary Factors

SummaryUnder the name of “Progenesis” (from the prefix “pro “, in front, and of the Greek “genesis “, generation) a new conception and classification of the factors of development were proposed by R. Turpin, the progenesis grouping “the whole of the hereditary and non hereditary factors that preexist to the fecundation and that concur to the formation of the being and to its development”.This conception has the advantage of designating indifferently, to all progenitic factor, hereditary as well as non hereditary, a place marked in advance; it has the advantage of showing beside the paternal maternal factors, the characteristic progenetical factors of the couple; it has the advantage to draw the attention on factors which were before neglected (age of mother, age of father, rank of birth, sex of the preceding pregnancy, interval between pregnancies, number of pregnancies, etc.) and whose importance increases in proportion as the gathering of the facts is abundant enough to lend itself to the statistical analyses; it has lastly the advantage of leading to an etiological prevention of the congenital defects, trying to draw the most advantage from the surrounding factors, without discarding, when they are imposed by the circumstances, the possibilities brought to their right proportion of the eugenic selection.To illustrate this progenesic conception of the ontogenesis a simple example, the gemellity, deserves to be retained.If we consider the gemellity as a deviation in regard to the simple pregnancies, it constitutes at the same time the more frequent and the best registered of anomalies. It lends itself to the study of its relations with divers progenesic factors which the authors regard by turns with the complement of their personal researches : age of the progenitors, rank of the pregnancy, sex of the product of the anterior last conception.If on the other hand, we consider the gemellity itself as a progenesic factor, we can study on the development, and for instance, which the authors have done, on the rate of masculinity. This study has lead them to put in value the phenomenon of diminution of the masculinity in relation to the degree of the multiplicity of pregnancy.

Taxonomic status of the genus Spermophilus (Mammalia: Rodentia) in Turkey and Iran with description of a new species

Zootaxa ◽  
2007 ◽  
Vol 1529 (1) ◽  
pp. 1-15 ◽  
Author(s):  
ŞAKIR ÖNDER ÖZKURT ◽  
MUSTAFA SÖZEN ◽  
NURI YIĞIT ◽  
IRFAN KANDEMIR ◽  
REYHAN ÇOLAK ◽  
...  
Keyword(s):  
New Species ◽  
Taxonomic Status ◽  
Statistical Analyses ◽  
The Other ◽  
Diagnostic Characters ◽  
Taurus Mountains ◽  
Spermophilus Citellus ◽  
Morphologic Data ◽  
First Time ◽  
A New Species

We report a new species of Spermophilus ( Rodentia: Sciuridae), here designated as S. torosensis sp. nov., distributed in the Taurus Mountains in southern Anatolia, Turkey. A total of 161 specimens of the genus Spermophilus from Turkey and Iran were analyzed for their morphological, morphometric, and karyological characteristics. Uni- and multi-variate statistical analyses of morphologic data for 95 adult specimens yielded 4 distinct groups. Taxonomic evaluations classified the specimens into 4 species Spermophilus citellus, S. xanthopymnus, S. fulvus and S. torosensis sp. nov. Morphometrics, coat coloration, a brush-shaped tail, and a NFa value of 72 are diagnostic characters that distinguish S. torosensis sp. nov. from the other species. In Turkey, S. torosensis sp. nov. was found in 6 locations. The karyotype of S. fulvus also is described for the first time as 2n= 36, NFa= 70 and NFa= 66; new karyotypic data is reported for S. xanthoprymnus from Iran and Turkey.

SEARCHING FOR SCALING IN THE PENNA BIT-STRING MODEL OF BIOLOGICAL AGING

2000 ◽  
Vol 11 (02) ◽  
pp. 309-315 ◽  
Author(s):  
K. MALARZ
Keyword(s):  
Computer Simulation ◽  
String Model ◽  
The Other ◽  
Biological Aging ◽  
Control Parameters ◽  
Genome Length ◽  
Model Control

In this paper the Penna bit-string model of biological aging with different lengths of bit-strings genome is considered. We show from computer simulation that changes in genome length may be crucial for determining population characterization and seem to be irreversible by scaling the other model control parameters.

Immunofluorescence of Aeromonas hydrophila as measured by fluorescence photometric microscopy

1980 ◽  
Vol 26 (2) ◽  
pp. 161-168 ◽  
Author(s):  
C. B. Fliermans ◽  
T. C. Hazen
Keyword(s):  
Fluorescence Microscopy ◽  
Aeromonas Hydrophila ◽  
Statistical Analyses ◽  
The Other ◽  
Aquatic Habitats

Strain-specific fluorescent antibodies were prepared for three isolates of Aeromonas hydrophila. These antisera were reacted with 255 other A. hydrophila isolates, and their immunofluorescence was measured quantitatively by photometric fluorescence microscopy. Only 27.5% of the isolates reacted with the prepared antisera which indicated that other undetected serogroups are present. Statistical analyses indicated that the A. hydrophila isolated from aquatic habitats were distinct from the other isolates as measured by immunofluorescence.

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