scholarly journals A Karyological Study in Some Species of Coffea L. and in the Closest Relative Psilanthus travancorensis (Wight & Arn.) J.-F. Leroy

2012 ◽  
Vol 40 (2) ◽  
pp. 39 ◽  
Author(s):  
Neiva Izabel PIEROZZI ◽  
Thalita C. BORGHI ◽  
Maria Bernadete SILVAROLLA

Chromosome characterization were carried out in Coffea kapakata A. Chev (Bridson), C. racemosa Lour., C. salvatrix Swynn. & Philipson and in Psilanthus travancorensis (Wight & Arn.) J.-F. Leroy (2n=22) by employing the conventional acetic orcein technique as well as by C- and NOR-banding aiming further comparative studies. Although C. canephora and C. dewevrei have already been studied and depict a C-band karyotype, they have also been included for further comparisons, since NOR-banding and some other morphometric data have not been obtained yet. However, there were observed some differences among the species regarding chromosomal morphometry. The karyotype formula obtained was 3m+6sm+2sms for C. salvatrix and P. travancorensis, 1M +2m + 6sm + 2sms for C. kapakata and 2M +1m + 6sm + 2sms for C. racemosa. All species displayed a moderate karyotype asymmetry and according to Stebbins system, C. canephora, C. dewevrei, C. kapakata and C. racemosa were classified as 3B while C. salvatrix and P. travancorensis were classified as 2A. Among the four indices used to assess karyotype asymmetry, Paszko AI index along with Stebbins were best suited to individualize the species. C-bands were preferentially situated at a pericentromeric/centromeric position. Two pairs of chromosomes, with secondary constriction and satellite segments, were observed in all the species following acetic orcein staining. C. racemosa and C. salvatrix showed NOR-band in both pairs, while only one chromosome pair carrying NOR-band was seen in C. canephora, C. dewevrei, C. kapakata and P. travancorensis. Data on chromosome morphometry, asymmetry indices and NOR-banding were suitable for the characterization of the species.

Biologia ◽  
2012 ◽  
Vol 67 (2) ◽  
Author(s):  
Paola Jara-Arancio ◽  
Pedro Jara-Seguel ◽  
Claudio Palma-Rojas ◽  
Gina Arancio ◽  
Raul Moreno

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.


1999 ◽  
Vol 22 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Nelson Colihueque V.

Chromosomal characterization of coho salmon samples from three fish farms in southern Chile (Polcura, Castro and Coyhaique) was carried out in order to compare their chromosome constitutions. All populations had a 2n = 60; however, Polcura and Coyhaique had a different chromosome arm number (NF = 110; 40m + 10sm + 10st/t) than Castro (NF = 108; 40m + 8sm + 12st/t). Variation in NF was due to chromosome pair 25, which was submetacentric in Coyhaique and Polcura, but subtelocentric in Castro. In all karyotypes, a large submetacentric chromosome pair exhibited an interstitial secondary constriction in the short arm. The observed variability in chromosome arm number agrees with previous reports for O. kisutch, and in this particular case it seemed to be caused by a pericentric inversion of pair 25. Cultured populations of Chilean coho salmon are, therefore, likely to be cytogenetically variable.


2011 ◽  
Vol 33 (spe1) ◽  
pp. 564-570 ◽  
Author(s):  
Neiva Izabel Pierozzi

Chromosome studies were performed in V. champinii, V. cinerea, V. girdiana, V. labrusca, V. rotundifolia, V. rupestris and V. vinifera with the purpose of species characterization using chromosome morphometric data and NOR banding. A median ideogram was obtained for each species. The karyotype formula obtained varied from 7m + 12sm to 9m + 11sm. The species showed moderate chromosome asymmetry values according to TF% form, Stebbins, Romero Zarco and Paszko indices. V. champinii and V. girdiana were apart from the other species by CVcl and CVci graphic representation and also formed a group apart in the dendrogram based on Euclidian distances. The chromosome pair number 3 harbors the secondary constriction and a satellite segment in all species analyzed with Giemsa staining and it may be the same observed after NOR banding technique. It seems that the process of speciation in the North American Euvitis species studied involved some discrete changes in chromosome morphometry which have been reflected in the asymmetry index.


2011 ◽  
Vol 33 (spe1) ◽  
pp. 546-551
Author(s):  
Neiva Izabel Pierozzi ◽  
Carlos Jorge Rossetto

Chromosome studies were performed in two varieties of Mangifera indica L. (mango), 'IAC-140 Espadona' and in its progenitor 'Espada Stahl'. Both varieties showed 2n=40 chromosomes though the karyotype formulae were 8m + 10sm + 2sm s for 'Stahl' and 7m + 11sm + 2sm s for 'IAC-140'. The varieties showed moderate karyotype asymmetry which was estimated according to four different indices. Both varieties exhibited three chromosome pairs with silver impregnation after NOR-banding. The number of nucleoli within interphase cells varied from one, the commonest, to eight. The nucleolus persistent phenomenon was observed in more than 22% of metaphase cells of both varieties, seeing that in 'Stahl', up to two nucleoli were evidenced. This variety also showed one nucleolus in several anaphase cells. The studies were suitable for evidencing diversity at chromosomal level between these two varieties.


2021 ◽  
Vol 12 (2) ◽  
pp. 110
Author(s):  
Febri Yuda Kurniawan ◽  
Anindita Della Rosa Riyadi

Peristylus goodyeroides is a terestrial orchid that scattered around Southeast Asia. Morphological characters of P. goodyeroides can vary, depending on the ecological factors and habitat. Cytological characters in the form of chromosome configurations can be used as a taxonomic tool for the process of identifying and understanding variations in taxa. The purpose of this study was to determine the morphological characters and chromosome configuration of the P. goodyeroides from Curug Setawing, Kulonprogo. The method used was morphological characterization and plant chromosome preparation by squash method with the main steps of fixation, maceration, staining and observation. Data were analyzed with the help of Image raster 3, Corel Draw X7, and Microsoft Excel 2013. P. goodyeroides from Curug Setawing has the morphological characters of root tubers, cylindrical stems, ovate leaf shape, convolutive leaf arrangement and creamy white flowers. The orchid has a number of chromosomes 2n = 10 with a karyotype formula of 2n = 2x = 8m + 2t. Metacentric chromosomes are found on chromosomes 1-8 and telocentric chromosomes 9-10. The absolute arm length of the chromosomes has a range of 2.03-3.44 μm, the relative arm length of the chromosomes is 2.21-3.32 μm, the length of the p arm is 1.13-1.58 μm and the q arm is 1.23-2.12 μm.


2010 ◽  
pp. 165-170 ◽  
Author(s):  
B.S. Daryono ◽  
D.A. Kumalawati ◽  
S. Abdullah

Author(s):  
Ana M. Bedoya ◽  
Adam D. Leaché

AbstractSpiny lizards in the genus Sceloporus are a model system among squamate reptiles for studies of chromosomal evolution. While most pleurodont iguanians retain an ancestral karyotype formula of 2n=36 chromosomes, Sceloporus exhibits substantial karyotype variation ranging from 2n=22 to 2n=46 chromosomes. In this study, we present two annotated chromosome-scale genome assemblies for the Plateau Fence Lizard (Sceloporus tristichus) in order to facilitate research on the role of pericentric inversion polymorphisms on adaptation and speciation. Based on previous karyotype work using conventional staining, the S. tristichus genome is characterized as 2n=22 with 6 pairs of macrochromosomes and 5 pairs of microchromosomes with a large pericentric inversion polymorphism on chromosome seven that is geographically variable. We provide annotated, chromosome-scale genomes for two lizards located at opposite ends of a dynamic hybrid zone that are each fixed for different inversion polymorphisms. The assembled genomes are 1.84 to 1.87 Gb (1.72 Gb for scaffolds mapping to chromosomes) with a scaffold N50 of 267.5 Mb. Functional annotation of the genomes resulted in 65,417 annotated genes, 16,426 of which were deduced to have a function. We confirmed the presence of a 4.62 Mb pericentric inversion on chromosome seven, which contains 59 annotated coding genes with known functions. These new genomic resources provide opportunities to perform genomic scans and investigate the formation and spread of pericentric inversions in a naturally occurring hybrid zone.


2010 ◽  
Vol 31 (3) ◽  
pp. 435-438 ◽  
Author(s):  
Orfeo Picariello ◽  
Gaetano Odierna ◽  
Emilio Balletto ◽  
Cristina Giacoma ◽  
Agnese Petraccioli

AbstractA karyological study conducted by both conventional and banding staining methods (Ag-NOR-, CMA3, and C-banding) evidenced a peculiar heterochromatin pattern on chromosomes of Moldovan specimens of the agile frog, Rana dalmatina. As is normal for all agile frogs, the Moldovan population presented 2n = 26 chromosomes, with NOR loci on the short arms of the third chromosome pair, but differed in showing heavy centromeric, CMA3 positive C-bands on the seventh chromosome pair, and light centromeric, DAPI positive C-bands on five chromosome pairs. In contrast, Moldovan specimens showed no significant difference in two segments of the 16S mitochondrial rRNA gene and in the S1 satellite DNA sequence and organization, in comparison with the GenBank deposited 16S rDNA and S1 DNA satellite sequences of R. dalmatina. Molecular similarity and chromosomal differences between agile frogs from Moldovan and extra-Moldovan populations are discussed.


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