scholarly journals Comparison of different cytological parameters of three species of Ocimum

2020 ◽  
Vol 49 (4) ◽  
pp. 1163-1167
Author(s):  
Trayee Biswas ◽  
Sandip Mukhopadhyay
Keyword(s):  
Coefficient Of Variation ◽  
Chromosome Length ◽  
Chromosome Morphology ◽  
Flowering Plants ◽  
Euclidian Distance ◽  
Total Chromosome Length

Karyomorphological analysis of three species of the genus Ocimum (O. basilicum L., O. americanum L. and O. tenuiflorum L.) was carried out. Gross chromosome morphology of these species are nearly sub metacentric (Sm), nearly metacentric (m) and metacentric (M) in nature. The high values of mean chromosome length, total chromosome length of O. americanum followed by O. basilicum show their primitiveness. Whereas, lower values of these parameters in O. tenuiflorum denotes evolved nature of the species. All the three species of Ocimum showed high values of total forma percentage (TF%) in conjunction with low coefficient of variation (CV), which corresponds to the primitive status in the evolution of flowering plants and was placed in 3A class of Stebbins’ system, indicating the presence of symmetrical karyotype in them. Karyotyping along with UPGMA based dendrogram analysis clearly separated O. basilicum L. and O. americanum L. in one cluster and O. tenuiflorum L. in a separate cluster with greater Euclidian distance.

scholarly journals Variation in actual relationship among descendants of inbred individuals

2012 ◽  
Vol 94 (5) ◽  
pp. 267-274 ◽  
Author(s):  
W. G. HILL ◽  
B. S. WEIR
Keyword(s):  
Coefficient Of Variation ◽  
Chromosome Length ◽  
Total Chromosome Length ◽  
Inbreeding Level ◽  
The Relationship ◽  
Actual Relationship

SummaryIn previous analyses, the variation in actual, or realized, relationship has been derived as a function of map length of chromosomes and type of relationship, the variation being greater the shorter the total chromosome length and the coefficient of variation being greater the more distant the relationship. Here, the results are extended to allow for the relatives’ ancestor being inbred. Inbreeding of a parent reduces variation in actual relationship among its offspring, by an amount that depends on the inbreeding level and the type of mating that led to that level. For descendants of full-sibs, the variation is reduced in later generations, but for descendants of half-sibs, it is increased.

Observations on chromosomes and gametogenesis ofTransversotrema patialense(Trematoda)

Parasitology ◽  
1986 ◽  
Vol 92 (1) ◽  
pp. 245-252 ◽  
Author(s):  
R. Mad Havi ◽  
J. V. Ramanjaneyulu
Keyword(s):  
Chiasma Frequency ◽  
Chromosome Length ◽  
Cytological Data ◽  
Total Chromosome Length ◽  
Diploid Complement ◽  
The Family ◽  
Phylogenetic Status ◽  
Snail Tissue

SUMMARYThe karyotype ofTransversotrema patia1enconsists of 10 pairs of chromosomes (2n= 20) of which 5 pairs are metacentrics and 5 pairs are submetacentrics. The chromosomes are large and range in size from 5 to 12 μm. The total chromosome length of the diploid complement is 16783 μm. Stages of spermatogenesis including the two gonial divisions and two reduction divisions leading to production of spermatozoa occur in cercarial embryos inside snail tissue, while the maturation divisions of the ovum occur in eggs freshly liberated by the fluke. The chiasma frequency is high, being 3888/cell and 388/bivalent. Cytological data indicate an independent phylogenetic status for the family Transversotrematidae.

Redescription of the karyotype of five species of the family Bufonidae (Amphibia: Anura) from central area of Argentina

Biologia ◽  
2011 ◽  
Vol 66 (3) ◽  
Author(s):  
Mariana Baraquet ◽  
Julián Valetti ◽  
Nancy Salas ◽  
Adolfo Martino
Keyword(s):  
Significant Contribution ◽  
Average Length ◽  
Chromosome Complement ◽  
Central Area ◽  
Chromosome Length ◽  
Chromosome Morphology ◽  
Morphometric Parameters ◽  
Classification Rate ◽  
The Family ◽  
Karyotype Formula

AbstractIn this study karyotypic features of the five species of the family Bufonidae from the central area of Argentina are described. The species are Rhinella achalensis, Rhinella arenarum, Rhinella fernandezae, Rhinella schneideri and Melanophryniscus stelzneri. The metaphases were obtained from intestinal and testis cells, using conventional techniques. Twenty metaphasic figures per individual were analyzed and the total length of each chromosome and the length of the four arms were measured. The obtained measurements were processed using Excel 2000 to obtain the average length of the arms p and q, the arm ratio, the centromeric index, the relative chromosome length and the relative arm length. All species showed karyotype 2n = 22, and karyotype formula of 6: 5. Pairs one to six were large, with a relative chromosome length between 18.64–7.59%; pairs seven to eleven were small, with a relative chromosome length between 7.18–2.42%. In all species the chromosome morphology was metacentric or submetacentric. Karyotype and ideograms were made for all species, based on morphometric parameters of the chromosome complement. Finally, discriminant analysis was used to separate the five species analyzed, with a highly significant classification rate of 80% and P < 0.0001. These results agree, in general, with those presented by other authors, however, in M. stelzneri detailed karyological studied have not been made so far, thus this work represents a significant contribution to the karyotypic decryption features of this species and the Rhinellla species from central area of Argentina.

scholarly journals Nucleic acid content and Chromosome morphology in Chrysanthemum

1969 ◽  
Vol 13 (3) ◽  
pp. 241-250 ◽  
Author(s):  
G. J. Dowrick ◽  
A. S. El Bayoumi
Keyword(s):  
Nucleic Acid ◽  
Chromosome Number ◽  
Dna Content ◽  
Chromosome Numbers ◽  
Chromosome Length ◽  
Chromosome Morphology ◽  
Nucleic Acid Content ◽  
Chromosome Size ◽  
Dna Contents ◽  
The Relationship

1. The DNA contents of twenty-eight different species and forms of Chrysanthemum have been measured by photometry. It is shown that there are large differences in DNA content between some species with identical chromosome numbers.2. The DNA contents of natural polyploids are frequently not those expected when comparison is made with diploid forms of the same species. The DNA contents of induced polyploids are those expected.3. Chromosome length and volume are positively correlated with DNA content.4. The relationship between chromosome number, chromosome size, DNA content and gene number is considered, and it is suggested that the differences in DNA content may result from the presence of differing amounts of genetically inactive DNA in the chromosomes.

TRISOMICS OF AVENA STRIGOSA

1975 ◽  
Vol 17 (2) ◽  
pp. 151-166 ◽  
Author(s):  
Tibor Rajhathy
Keyword(s):  
Transmission Rate ◽  
Extra Chromosome ◽  
Chromosome Length ◽  
Chromosome Morphology ◽  
Balance Theory ◽  
Primary Trisomics ◽  
Qualitative And Quantitative ◽  
Dosage Effects ◽  
Avena Strigosa ◽  
Small Seed

A set of seven primary trisomics and seven derived types were produced in Avena strigosa Schreb., a diploid oat species. Each trisomic type had a distinct phenotype. The primary trisomics were identified on the basis of plant and chromosome morphology. Although fertility (seed-set) and the frequency of transmission of the extra chromosome varied among selfed progenies of the various trisomics, each trisomic can be maintained. The trisomics occurred at a higher frequency in small seed fractions than in samples of large seeds. No straightforward relationship was apparent between chromosome length and trivalent formation but some association between trivalent formation and transmission rate was observed.Several qualitative and quantitative traits were compared between the primary telotri-somics, between these and the disomic and between opposite arm telotrisomics and their corresponding primary trisomic. It was concluded that the results are more compatible with dosage effects than with the gene balance theory.

Giemsa C-banded karyotypes of Hordeum taxa from North America

1986 ◽  
Vol 28 (1) ◽  
pp. 42-62 ◽  
Author(s):  
I. Linde-Laursen ◽  
Roland von Bothmer ◽  
Niels Jacobsen
Keyword(s):  
Diagnostic Marker ◽  
Marker Chromosome ◽  
Chromosome Length ◽  
Chromosome Morphology ◽  
Banding Patterns ◽  
C Banding ◽  
Close Relationship ◽  
Partial Inactivation ◽  
Pattern Polymorphism ◽  
Nucleolus Organizers

Giemsa C-banding patterns of Hordeum pusillum, H. intercedens, H. brachyantherum (2x, 4x, 6x), H. jubatum, H. arizonicum, and H. depressum (2x and 4x) were rather similar, with mostly small to very small bands with no preferential disposition. The use of C-banding patterns did not improve the level of identification of taxa beyond that reached by the use of chromosome morphology. Widespread banding-pattern polymorphism prevented a reliable identification of homologues among populations based on this character alone. Chromosome length did not differentiate taxa. The ratio longest/shortest chromosome was remarkably constant over taxa, only differentiating the race of H. brachyantherum (4x) from Newfoundland, H. arizonicum, and H. depressum (4x). Marker chromosome morphology suggested the presence of one genome common to all taxa. A further but different genome was common to the perennial polyploids, indicating an alloploid origin and a close relationship calling into question the biological relevance of some sectional divisions in Hordeum. A number of intraspecific chromosome polymorphisms were observed rendering the number of marker chromosomes, a poor diagnostic marker. A pair of relatively shorter submetacentrics than previously reported in Hordeum distinguished the genomes of H. arizonicum and H. brachyantherum (4x) from Newfoundland. A partial inactivation of the nucleolus organizers of one parental genome in interspecific hybrids is considered more common than generally appreciated.Key words: C-banding, karyotype, Hordeum.

scholarly journals Karyotype Variation in Eight Cultivars of Indian Dessert Banana (Musa acuminata L.) of Section Eumusa From Odisha, India

Caryologia ◽  
2021 ◽  
Vol 74 (1) ◽  
pp. 23-31
Author(s):  
Shomina Dehury ◽  
Subrat Kumar Dehery ◽  
Anath Bandhu Das
Keyword(s):  
Chromosome Number ◽  
Chromosome Length ◽  
Basic Chromosome Number ◽  
Small Chromosome ◽  
Market Demand ◽  
Ploidy Levels ◽  
Total Chromosome Length ◽  
Size Diversity ◽  
Cytogenetic Characterization ◽  
Important Cash Crop

Banana (Musa spp.) cultivars especially dessert banana are important cash crop with high market demand all over the world as an integral part of the diet. The need for assessment of cytogenetic characters in Musa cultivars is inevitable as out of thousands of cultivars, cytogenetic characterization of most of them remains unresolved due to difficulties like small chromosome size, diversity in ploidy levels and high cultivar diversity which behave differently to standardized cytogenetic protocols. In this report, somatic chromosome number, detailed karyotype analysis including total chromosome length, volume, form percentage, Interphase Nuclear Volume (INV) were accessed on eight dessert type of Musa accessions from different places of Odisha. All the cultivars studied were found triploid (2n = 33) with a basic chromosome number of x=11. The karyotype formulae were assigned to each cultivar by grouping the chromosome according to their shared characteristics. The total chromosome length ranged from 54.95 µm in cv. Robusta to 81.5 µm in cv. Kathia with symmetric karyotype in all the studied cultivar. Karyotype formula revealed structural alteration of chromosome with Total Form percentage (TF%) variation from 35.65% in cv. Amritapani to 41.68% in cv. Patakpura that confirms more number of nearly median constricted chromosome as compared to sub-median chromosome. The total chromosome volume recorded from 10.78 µm3 in cv. Robusta to 15.99 µm3 in cv. Khatia and the INV varied from 1336.44 µm3 in cv. Dwarf Cavendish to 2048.37 µm3 in cv. Patakpura. The recorded structural variation might be due to differential genome specific condensation of chromosome. Chromosome length and volume found statistically significant among the cultivars. 

CHROMOSOME MORPHOLOGY OF POA TRIVIALIS L.

1972 ◽  
Vol 14 (2) ◽  
pp. 287-291 ◽  
Author(s):  
M. K. Ahmed ◽  
G. Jelenkovic ◽  
W. R. Dickson ◽  
C. R. Funk
Keyword(s):  
Chromosome Number ◽  
Chromosome Complement ◽  
Chromosome Length ◽  
Chromosome Morphology ◽  
Length Ratio ◽  
Poa Trivialis

The chromosome complement in six turf-type genotypes of Poa trivialis was studied. The chromosome number was 2n = 2x = 14. On the basis of chromosome length, ratio between arm lengths, centromeric indices, and presence of constrictions all seven pairs were identified and characterized.

scholarly journals Karyotypes and genome size of Adonis amurensis and Adonis apennina (Ranunculaceae) from Asian Russia

2021 ◽  
Vol 11 (1) ◽  
pp. 163-170
Author(s):  
E.Yu. Mitrenina ◽  
A.S. Erst ◽  
W. Wang
Keyword(s):  
Coefficient Of Variation ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Chromosome Length ◽  
Asymmetry Index ◽  
Amur Oblast ◽  
Altai Republic ◽  
Karyotype Asymmetry ◽  
Karyotype Formula

The karyotypes of Adonis amurensis from Amur Oblast,' and Adonis apennina from Altai Republic, Khakassia Republic, and Irkutsk Oblast' have been investigated. The karyotype formula was obtained as 2n = 2x =16 = 8m + 8sm(4sat) for all specimens. We estimated karyotype asymmetry through the calculation of the Coefficient of Variation of Chromosome Length (CVCL), Coefficient of Variation of Centromeric Index (CVCI), and Mean Centromeric Asymmetry (MCA), and determination of Stebbins asymmetry index. The chromosome set of Adonis amurensis was found to be more symmetrical than the chromosome set of Adonis apennina. The average absolute nuclear DNA content (2C–value) was originally determined for Adonis amurensis and Adonis apennina by flow cytometry and attained on average 20.38 pg and 17.29 pg, respectively.

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