CYTOLOGIA
Online ISSN : 1348-7019
Print ISSN : 0011-4545
Volume 62, Issue 1
Displaying 1-14 of 14 articles from this issue
  • D. Yüzbasioglu, F. Ünal, H. Duman
    1997 Volume 62 Issue 1 Pages 1-6
    Published: March 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    Karyotype and C-banding analyse have been performed to Sternbergia lutea and S. sicula from Turkey. While S. lutea was found to be diploid (2n = 22) and triploid (2n = 33), S. sicula proved to be diploid with 2n = 22. Chromosome lengths in S. lutea and S. sicula are 19.85-5. 15 μm and 17.88-5.16 μm, respectively. While all chromosomes in S. lutea showed centromericC-band, in S. sicula, eight chromosomes carry constitutive heterochromatin, being centromeric on seven and interstitial on one. Three chromosomes, 4, 7 and 10, in S. sicula, show no C-band.Based on these results, the relationships between the two taxa are discussed.
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  • Elzbieta Warchalowska-Sliwa, Alexander G. Bugrov
    1997 Volume 62 Issue 1 Pages 7-12
    Published: March 25, 1997
    Released on J-STAGE: February 22, 2010
    JOURNAL FREE ACCESS
    The Mongolian-Siberian species Deracantha onos (2n = 29, NF = 31) is characterized by an extensive amount of C-heterochromatin occurring on the M2 chromosomes as a large interstitial C-block and on M6, S8, S9, and S10 chromosomes as large distal C-bands.
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  • Supriya Gandhi, V. P. Patil
    1997 Volume 62 Issue 1 Pages 13-18
    Published: March 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    Seeds and seedling of Clitoria ternatea L. white (Family Papilionaceae) were treated with colchicine solution from 0.05% to 0.25% concentrations for different durations. Shoot immersion method resulted in 4 colchiploid (C0) plants from which 10 C1 plants were obtained. Expression of gigantism in morphological characters such as plant height, size of leaflets, flowers, seeds and pollen diameters was noted in these autotetraploids with significant decrease in stomatal frequency, percent pollen fertility and seeds/pod ratio. Karyotypic study of the autotetraploid plant indicated 2n = 32 with all submedian chromosomes.
    Chromosome association at diakinesis and metaphase-I revealed gradual decrease in quadrivalent frequency with increase in bivalent frequrncy from C0 to C1 generation. Meiotic abnormalities were also reduced in C1 plants as compared to C0 plant.
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  • V. Ferreira, B. Szpiniak, L. Reynoso
    1997 Volume 62 Issue 1 Pages 19-24
    Published: March 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    Echinochloa helodes (Hackel) Parodi grows naturally in Argentina, Uruguay and Brazil. It is a perennial, semihalophyte, rhizomatous and hygrophylic Summer grass, in naturally wet lands it is a good forage resource. This paper analyzes numeric chromosomic variants, sexual reproduction and seed retention in four populations of Argentina and Uruguay, through the study of meiotic behavior, pollen stainability and seed production in self-and open-pollinated panicles. All collections showed 6x level, with 27 bivalents at diakinesis-metaphase I and normal migration 27 : 27 in early anaphase I. Pollen stainability was 93%. Seed set was poor (10.5%) in self-pollinated panicles, but over 53% after open pollination, indicating the prevalence of allogamy. No seed retention was found.
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  • Alice Maria de Souza, Maria Suely Pagliarini
    1997 Volume 62 Issue 1 Pages 25-29
    Published: March 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    During an investigation of the meiotic behavior of 11 canola cultivars (Brassica campestris and Brassica napus.), eight were found to present cytomixis between sporocytes. The percentage of cells with cytomixis was low, ranging from 0.06 to 2.55%. In two cultivars, cytoplasmic bridges without chromatin transfer between cells were higher than cytomixis. All meiotic phases from pachytene to tetrads were affected. Chromosome transfer was observed between cells in the same phase of division and also between cells in different phases of division. The amount of nuclear material transferred from one cell to the other was variable, involving, in some cases, the entire chromosome complement.
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  • M. Fareed Khan, Gareth M. Evans
    1997 Volume 62 Issue 1 Pages 31-38
    Published: March 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    This paper gives the results of breeding system and cytological investigations on Cenchrus ciliaris L. a grass of District Rawalakot, Azad Kashmir-Pakistan. It is confirmed that Cenchrus ciliaris is apomict, probably a facultative apomict.
    The meiotic results indicated that the chromosome pairing of this species was somewhat irregular, showing multivalents at metaphase I of meiosis. Cenchrus ciliaris is suggested to be allotetraploid with 2n = 34. The chromosome number 2n = 34 of this ecotype from Azad Kashmir-Pakistan, could be derived from 2n = 36, by the loss of a single pair of chromosome. It is concluded that all meiotic irregularities are indirectly associated with the apomictic phenomena of reproduction.
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  • M. G. M. Franzoni, M. A. A. Castro-Prado, J. S. Gebara
    1997 Volume 62 Issue 1 Pages 39-45
    Published: March 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    The recombinogenic effect of norfloxacin was studied in a heterozygous diploid Aspergillus nidulans strain. Both 0.8 and 1.5, μg/ml of norfloxacin produced homozygosity of recessive genes in chromosomes I and II. The same concentrations also induced crossing-over in mitotic segregants, but did not produce morphological changes or differences in the growth curve.
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  • T. Yabuya, S. Kihara, H. Yoshino, A. Ohba
    1997 Volume 62 Issue 1 Pages 47-51
    Published: March 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    The behavior of NOR-bearing telosomes in the telotrisomic and its telocentric progenies of Iris ensata was examined by a silver-staining method. In the cross of the telotrisomic “Telotri-1” × the diploid cultivar “Shishinden”, the female transmission rate of a telosome was 15. 6%. All the telotrisomics except one (Telotri-1-1) had 4 NOR-bearing chromosomes and a telosome with 2 Ag-NOR bands which were observed in the maternal plant “Telotri-1”, and a telosome with 2 Ag-NOR bands in the monotelodisomic “Monotelodi-1” was also transmitted from the maternal one. On the contrary, the telotrisomic “Telotri-1-1” had 5 NOR-bearing chromosomes and a telosome with 1 Ag-NOR band. The appearance of this telosome provided the conclusive proof that a simple translocation of 1 Ag-NOR band of the telosome with 2 Ag-NOR ones to a non NOR-bearing chromosome took place in “Telotri-1”. Such a structural change of the telosome was recognized in 9.1% of the telocentric progenies of “Telotri-1”.
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  • M. F. Rocha, M. J. Souza, T. Tashiro
    1997 Volume 62 Issue 1 Pages 53-60
    Published: March 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    The genus Radacridium (Romaleidae) is endemic in the Northeast region of Brazil and is chromosomally described here using specimens collected in the Agreste (R. mariajoseae) and in the Caatinga (R. nordestinum), State of Pernambuco. Both species presented 2n = 23, XO in males and acrocentric chromosomes. The two species can be distinguished on the basis of C-banding patterns and location of the nucleolar organizer regions (NORs). R. mariajoseae showed C-bands only in the pericentromeric regions of autosomes L1, M9, S10 and S11 and in the proximal regions of L2. Chromsome X presented proximal and distal pericentromeric bands. R. nordestinum, in turn, has pericentromeric bands in all chromosomes and interstitial bands in pairs L2 and M5. The bivalent M9 corresponds to the megameric chromosome for the two species. Furthermore, R. nordestinum presented four chromosome pairs (L3, M4, M6, M7) bearing supernumerary heterochromatin segments that were absent in R. mariajoseae. In R. nordestinum a comparative analysis of standard karyotypes and karyotypes with an interstitial supernumerary segment in pair 4 revealed chiasma redistribution in all chromosome groups, with no change in mean chiasma frequency per cell. The nucleolar organizer chromosome was the X in R. mariajoseae and the L2 pair in R. nordestinum. Cores and kinetochores stained identically in the two species. Taken together, the chromosome data show that these species are cytogenetically well distinct.
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  • P. C. Vissotto, F. Foresti, C. Oliveira
    1997 Volume 62 Issue 1 Pages 61-66
    Published: March 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    The cytogenetic analysis of 21 specimens of Imparfinis mirini showed the presence of 2n = 58 chromosomes in animals of both sexes. The basic karyotype consists of 22 metacentric and 34 submetacentric chromosomes plus one homomorphic pair (M/M) in males and one heteromorphic pair (M/SM) in females. Ag-NORs were located interstitially on the long arms of the largest metacentric pair and differences were frequently found concerning NOR size in the homologues. I. mirini presents a relatively large quantity of constitutive heterochromatin located in pericentromeric, interstitial and telomeric positions in several chromosome pairs. The occurrence of a heteromorphic chromosome pair in females was demonstrable by the presence of one extra C-banded segment added to the long arm of the W chromosome. The occurrence of detectable heteromorphism involving the sex chromosomes among fishes is discussed.
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  • Mei-Chu Chung, Hsin-Kan Wu
    1997 Volume 62 Issue 1 Pages 67-79
    Published: March 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    The chromosomal instability described herein occurred spontaneously among the progenies of Triplo 1 and Triplo 4, which are two of the twelve rice trisomic lines established at IRRI. In Triplo 1, some trisomic plants have been identified to have an extra chromosome 8 instead of extra chromosome 1. Cytological evidence revealed that the instability found in Triplo 1 was originated from the breakage of chromosome 8. The resulting chromosomal fragment carrying mainly heterochromatin could provoke chromosome non-disjunction at meiosis. We suggest that the appearance of non-parental trisomics was resulted from the event of non-disjunction of chromosomes 8. Since the longer chromosomes would cause more imbalance than the shorter ones, chromosome 8 is much smaller than chromosome 8 and greatly favored its transmission over chromosome 1 as extra chromosome found among the trisomic progenies of Triplo 1. Triplo 4 had been previously designated as Triplo 12 for having a very short extra chromosome. In this study, we present the evidence indicating that the instability of Triplo 4 was induced by two subsequent breaks of chromosome 4.
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  • Neiva I. Pierozzi, Sigrid L. Jung Mendacolli
    1997 Volume 62 Issue 1 Pages 81-90
    Published: March 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    Genipa L. (Rubiaceae) is a small genera with only three neotropical species. Karyological studies were developed in two of these species, G. americana (2n = 22) and G. infundibuliformis (2n = 20), by acetic orcein 2% and Giemsa C-band techniques. Haploid karyotype formulas were n =11 : 3m + 7sm + 1 sms and n =10 : 2m + 7sm + 1 sms, respectively. Chromosomes 3, 7 and 11 of G. americana and 3 and 5 of G. infundibuliformis were metacentrics and the others were submetacentrics. Chromosomes 1 and 4 had secondary constriction and according to the cytological observations only chromosome 4 had the NOR. Even so both species are dioecious, it have not been seen any chromosome or heterochromatin heteromorphism that could be associated to sexual differences. Both species had a high amount of heterochromatin revealed by C-band technique. G. infundibuliformis had the more asymmetric karyotype but the lesser chromosome sizes, heterochromatin amount and karyotype length. Preliminar comparative studies were done in both species and it were discussed the possible phylogenetic relationships.
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  • O. L. Suma, H. A. Ranganath
    1997 Volume 62 Issue 1 Pages 91-95
    Published: March 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    The heterochromatin of three species of the montium subgroup of Drosophila, namely, D. nagarholensis, D. jambulina and D. kikkawai has been analysed. Within the basic karyotypic configuration of 2n = 8, interspecies differences in the pattern and the intensity of C-and Q-band heterochromatin particularly of Y and dot chromosomes have been recorded.
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  • Tamotsu Kawazu, Haruko Kuroiwa, Shigeyuki Kawano
    1997 Volume 62 Issue 1 Pages 97-102
    Published: March 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    The behavior of Golgi bodies in a maize root tip was examined by the Technovit DiOC6-DAPI double-stain method. In almost all regions of the root tip, Golgi bodies were observed as bright and rod-like DiOC6 fluorescence. The number or shape of Golgi bodies varied in different tissues. Their density was quite high in two regions, the root cap initials and the upper end of the outer root cap were especially full of Golgi bodies. The Golgi bodies were uniformly small in the meristem and the root cap initials, but were much larger in the outer root cap, and this seems to be because they produce polysaccharide-slime.
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