scholarly journals Cytological Studies on Two Species, Xanthium strumarium Linn. and Bidens pilosa Linn. Var. minor (Blume) Sherff (Asteraceae-Heliantheae) from Nepal

2017 ◽  
Vol 5 (1) ◽  
pp. 66-71
Author(s):  
Pushpa Karna
Keyword(s):  
Chromosome Number ◽  
Chromosome Length ◽  
Terminal Region ◽  
Xanthium Strumarium ◽  
Pollen Stainability ◽  
Bidens Pilosa ◽  
Median Region ◽  
Absolute Length ◽  
Karyotype Formula ◽  
Median Point

Karyotype, meiosis and pollen stainability of the taxa Bidens pilosa L. var. minor (Blume) Sherff and Xanthium strumarium L. collected from central part of Nepal was cytologically carried out. Results obtained from this investigation showed that chromosome number in somatic cells were recorded to be 2n=36 in Bidens pilosa and 2n=32 in Xanthium strumarium using aceto-orceine squash technique. Likewise haploid chromosome number in reproductive cells were recorded to be n=18 in Bidens pilosa and n=16 in Xanthium strumarium using aceto-carmine squash technique. The range of chromosome length found to be 0.4 to 2.1 µm in Bidens pilosa and 0.4 to 1.6 µm in Xanthium strumarium. Karyotype formula was M16+m2+sm14+st4 for Bidens pilosa and M18+ sm12+st2 for Xanthium strumarium. Based on the position of the centromeres, the chromosomes were categorized into four types with centromere at median point, median region, sub median region and terminal region in Bidens pilosa whereas three types, namely chromosomes with centromere at median point, sub median region and sub terminal region in Xanthium strumarium . In Bidens pilosa karyotype is asymmetrical and slightly asymmetrical karyotype is found in Xanthium strumarium. Absolute length recorded in Bidens pilosa were 19.2µm and 15.8. µm in Xanthium strumarium . Pollen stainability is found to be 94.0 percent in Bidens pilosa and 92.7 percent in Xanthium strumarium.Int. J. Appl. Sci. Biotechnol. Vol 5(1): 66-71

scholarly journals Karyomorphology, Meiotic Behaviours and Pollen Fertility of Calendula officinalis L. (Calenduleae- Asteraceae)

2021 ◽  
Vol 9 (1) ◽  
pp. 75-79
Author(s):  
Pushpa Karna Mallick
Keyword(s):  
Chromosome Number ◽  
Pollen Fertility ◽  
Somatic Chromosome ◽  
Chromosome Length ◽  
High Fertility ◽  
Calendula Officinalis ◽  
Middle Point ◽  
Central Nepal ◽  
Median Region ◽  
Absolute Length

The present study includes chromosome number, karyomorphology, meiotic behaviors and pollen fertility of   the species Calendula officinalis L.collected from central Nepal was cytologically carried out using two percent aceto-orcein for somatic chromosome determination and one percent aceto-carmine for meiotic study. Pollen fertility was based on stainability test using Muntzing solution. Somatic chromosome number determined for this taxon were 2n=28, haploid chromosome number n=14 and pollen fertility found to be 84.4 percent in the   present study. In karyotype analysis chromosome length ranged from 0.4 to 2.6 µm and mean length was 1.5 µm.  Likewise, absolute length found to be 21.9 µm and karyotype formula obtained was M16+m4+ sm8. Three types of chromosomes centromere at middle point, at median region and at sub –median region were observed. Meiosis with regular and irregular behaviors was observed in this study. The variations in chromosome numbers, irregularities in meiotic behaviors, variations in karyomorphological structure and high fertility rate shows evolve nature of this species which play a great role in evolution. Pollen fertility was also affected by meiotic abnormalities.  Int. J. Appl. Sci. Biotechnol. Vol 9(1): 75-79

Chromosome morphology of Clematis, subsection Viornae (Ranunculaceae)

1976 ◽  
Vol 54 (10) ◽  
pp. 1135-1139 ◽  
Author(s):  
W. Michael Dennis
Keyword(s):  
Chromosome Number ◽  
Somatic Chromosome ◽  
Chromosome Complement ◽  
Chromosome Morphology ◽  
Terminal Region ◽  
Somatic Chromosome Number ◽  
Median Region ◽  
Acrocentric Chromosomes ◽  
Subterminal Region ◽  
Marked Stability

Cytological studies were made on the following taxa: C. addisonii, C. filifera, C. glaucophylla, C. pitcheri, C. reticulata, C. texensis, C. versicolor, and C. viorna. All species were found to have a somatic chromosome number of 16 with a uniform karyotype consisting of five pairs of metacentric chromosomes with centromeres in the median region and three pairs of acrocentric chromosomes, two pairs with centromeres in the terminal region and one pair with centromeres in the subterminal region. These findings agree with reports of chromosome number and karyotype for other species of Clematis and suggest a marked stability of chromosome complement in the genus.

scholarly journals Karyotypic Analysis of four Species of Genus Blumea (Asteraceae) from Nepal

2018 ◽  
Vol 6 (2) ◽  
pp. 115-121
Author(s):  
Pushpa Karna Mallick
Keyword(s):  
Chromosome Number ◽  
Structural Variation ◽  
Chromosome Length ◽  
Evolutionary Significance ◽  
Satellite Chromosome ◽  
Middle Point ◽  
Karyotypic Analysis ◽  
The Family ◽  
Karyotype Formula ◽  
Blumea Lacera

In this study chromosome number determination and karyotype analysis of four species of genus Blumea from the family asteraceae was carried out. The specimen plants were collected from central parts of Nepal, namely  Blumea fistulosa (Roxb.) Kurz, Blumea lacera var.glandulosa (DC.) Hook, Blumea lacera (Buem f.) DC. and  Blumea laciniata DC were observed. The chromosome number in somatic cells were recorded to be 2n= 22 in Blumea fistulosa; 2n= 32 in  Blumea lacera var.glandulosa; 2n=18 in Blumea lacera and Blumea laciniata. The range of chromosome length found to be 0.6 to 1.6 µm in  Blumea fistulosa, 0.6 to 1.6µm in Blumea lacera var.glandulosa, 0.6 to 1.7 µm in Blumea lacera and 0.8 to 1.6 µm in Blumea laciniata. Karyotype formula for Blumea fistulosa is M12+ sm10, for Blumea lacera var. glandulosa is M14+sm14+ st4, for Blumea lacera is M14+ st2  and for Blumea laciniata is M12+ sm6 in  Blumea laciniata. In this investigation a pair of satellite chromosome found in  only one species Blumea  fistulosa at the end of shot arm of chromosome. Mainly three types of chromosomes observed in this study  having centromere at middle point, at sub-median region and at sub-terminal region. Numerical and structural variation in chromosome are evolutionary significance.  Similarity in size of chromosomes and karyomorphology indicates the homogeneity of the taxa within this tribe. Int. J. Appl. Sci. Biotechnol. Vol 6(2): 115-121

scholarly journals Chromosome counts of eight Iranian endemic species of Nepeta L. (Lamiaceae)

Caryologia ◽  
2021 ◽  
Vol 74 (1) ◽  
pp. 53-61
Author(s):  
Maryam Hasaninejad ◽  
Ziba Jamzad ◽  
Saeid Afsharzadeh ◽  
HojJatollah Saeidi
Keyword(s):  
Chromosome Number ◽  
Species Group ◽  
Chromosome Length ◽  
Basic Chromosome Number ◽  
Chromosome Counts ◽  
Ploidy Levels ◽  
Study Results ◽  
Karyotypic Diversity ◽  
Karyotype Formula ◽  
First Time

In this survey, the chromosome counts of eight Nepeta L. species were investigated and the karyotypic diversity among these species was studied. The examined species belong to N. cephalotes Boiss. species group, namely N. eremokosmos Rech.f., N. gloeocephala Rech. f., cephalotes Boiss., N. pungens (Bunge) Benth., N. ispahanica Boiss., N. mahanensis Jamzad & Simonds, N. hormozganica Jamzad and N. denudata Benth. collected from different habitats in Iran. The ploidy levels, karyotype formula, chromosome length range, total karyotype length, several karyotype asymmetries values and Stebbins classification were determined in this study. Results showed the same chromosome number, 2n = 2x= 18 for all studied species. The basic chromosome number for the above mentioned species are x = 9. Also, the smallest chromosome length is 1.02 μm in N. mahanensis. The largest chromosome length is 2.3 μm in N. ispahanica. The chromosomes of species were metacentric or submetacentric. According to the Stebbins classification, these species were located into three classes 1A, 2A and 3A. The chromosome numbers for six of studied species are reported here for the first time.

Karyological notes on another eight species of Achillea (Asteraceae) from Turkey

Biologia ◽  
2008 ◽  
Vol 63 (3) ◽  
Author(s):  
Yasar Kiran ◽  
Turan Arabaci ◽  
Ahmet Sahin ◽  
Ismail Turkoglu
Keyword(s):  
Chromosome Number ◽  
B Chromosomes ◽  
Natural Habitats ◽  
Median Region ◽  
Median Point

AbstractThe chromosome number and morphology in eight species of the sections Ptarmica (Mill.) W. D. J. Koch, Anthemoideae (DC.) Heimerl, Arthrolepis Boiss., Santolinoideae (DC.) Heimerl and Achillea of the genus Achillea L. (Asteraceae) were investigated using karyological techniques. Sample plants and seeds of A. biserrata M. Bieb., A. fraasii var. troiana Aschers. & Heimerl, A. multifida (DC.) Boiss., A. brachyphylla Boiss. & Hausskn., A. pseudaleppica Hub.-Mor., A. cretica L., A. latiloba Ledeb. ex Nordm., and A. kotschyi Boiss. subsp. kotschyi) were collected from natural habitats in 2003 and 2004. The chromosome number found in seven species was 2n = 18, while only A. kotschyi had 2n = 36. All chromosomes had median point (M), median region (m), and submedian (sm) centromers. In addition, only A. biserrata species had one subterminal (st) chromosome. An increase in asymmetry was not observed in the karyotypes of the species studied. None of the studied species had any B chromosomes.

scholarly journals Chromosome and pollen morphology of the rare endemic Centaurae lycopifolia Boiss. & Kotschy

2011 ◽  
Vol 39 (2) ◽  
pp. 223-228 ◽  
Author(s):  
AN Gomurgen ◽  
I Potoglu Erkara ◽  
H Altnozlu
Keyword(s):  
Electron Microscope ◽  
Chromosome Number ◽  
Scanning Electron Microscope ◽  
Pollen Morphology ◽  
Chromosome Length ◽  
Exine Ornamentation ◽  
Karyotype Formula ◽  
Rare Endemic ◽  
Haploid Karyotype ◽  
Scanning Electron

Chromosome and pollen morphology of Centaurea lycopifolia Boiss. & Kotschy were studied. The chromosome number is 2n = 34 with haploid karyotype formula 9m + 9sm. Metaphase chromosome length ranging from 6.16 to 2.23 μm and the total haploid chromosome length was 65, 85 μm. The light and scanning electron microscope investigations revealed spheroidal-subprolate, the amb triangular and tricolporatae pollens in the taxon. Exine ornamentation was tectatae and microechinate-scabrate. Key words: Centaurea lycopifolia; Chromosome; Pollen morphology; Endemic; Turkey DOI: 10.3329/bjb.v39i2.7484 Bangladesh J. Bot. 39(2): 223-228, 2010 (December)

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.

Karyological study in fifteen Leucocoryne taxa (Alliaceae)

Biologia ◽  
2012 ◽  
Vol 67 (2) ◽  
Author(s):  
Paola Jara-Arancio ◽  
Pedro Jara-Seguel ◽  
Claudio Palma-Rojas ◽  
Gina Arancio ◽  
Raul Moreno
Keyword(s):  
Chromosome Number ◽  
Secondary Constriction ◽  
Chromosome Morphology ◽  
Chromosome Size ◽  
Chromosome Fusion ◽  
Karyological Study ◽  
Karyotype Asymmetry ◽  
Additional Chromosome ◽  
Karyotype Formula ◽  
Haploid Karyotype

AbstractThe karyotype of fifteen Leucocoryne taxa was studied, assessing characteristics such as chromosome morphology and size, secondary constriction location, and asymmetry level. Two groups of Leucocoryne taxa were described based on chromosome number (2n = 10 and 2n = 18) and karyotype asymmetry. The haploid karyotype formula for the group 2n = 10 was 3m + 2st (or 2t), whereas for the group 2n = 18 was 7m + 2st (or 2t). Such results corroborate the karyotype descriptions previously carried out for some taxa of the genus. Leucocoryne taxa showed a high resemblance in chromosome morphology, but inter-specific differences were found in mean chromosome size. These data and previous studies based on gross chromosome morphology support Crosa’s hypothesis, which suggests that the cytotype 2n = 10 is diploid and perhaps ancestral, whereas that the cytotype 2n = 18 is tetraploid but with an additional chromosome fusion being probably a derived status.

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.

scholarly journals Karyomorphology of Two Species of the Genus Spilanthes (Heliantheae-Asteraceae)

2020 ◽  
Vol 8 (4) ◽  
pp. 422-426
Author(s):  
Pushpa Karna Mallick
Keyword(s):  
Chromosome Number ◽  
Somatic Chromosome ◽  
Relative Length ◽  
Home Garden ◽  
Somatic Chromosome Number ◽  
Great Role ◽  
Mitotic Chromosomes ◽  
Central Nepal ◽  
Spilanthes Acmella ◽  
Karyotype Formula

In present investigation karyotype of mitotic chromosomes were determined, two species of the genus Spilanthes, namely Spilanthes acmella (L.) Murray and Spilanthes calva DC. from plants transplanted in earthen pots collected from different localities from Central Nepal in my home garden. The somatic chromosome number determined in present study were 2n=36 for both species, Spilanthes acmella (L.) Murray and Spilanthes calva DC. The chromosomes total length ranged from 0.6 to 1.6 µm in Spilanthes acmella (L.) Murray and 0.4 to 2.1µm in Spilanthes calva DC. The relative length ranged from 2.3 to 12.1 µm in the species Spilanthes calva and 2.0 to 8.5 µm in the species Spilanthes acmella. The Karyotype formula were M16+m2+sm16+st2 in Spilanthes calva DC. and M22 +sm14 in Spilanthes acmella (L.) Murray cytologically obtained by using 2% aceto-orcein. The karyotype of the two species shows considerable variation exists in morphology of chromosome and structure. The variation in karyomorphology shows evolved nature of this species which play a great role in evolution. Int. J. Appl. Sci. Biotechnol. Vol 8(4): 422-426

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