CYTOLOGIA
Online ISSN : 1348-7019
Print ISSN : 0011-4545
Volume 50 , Issue 1
Showing 1-25 articles out of 25 articles from the selected issue
  • V. K. Singhal, B. S. Gill, S. S. Bir
    1985 Volume 50 Issue 1 Pages 1-8
    Published: March 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Cytological studies have been carried out on six species of the family Malpighiaceae. The count of 2n=20 for Banisteria laevifolia adds a new diploid cytotype and establishes intraspecific polyploidy for the species. A new cytotype of 2n=60 has been recorded for Hiptage benghalensis which establishes the highest number for the family. The record of B-chromosomes for the two species, B. laevifolia and H. benghalensis are also the first counts for the family.
    Presence of univalents in diploid species, B. laevifolia and Stigmaphyllon ciliatum is due to the partial nonhomology in some of the chromosomes. Multiple associations along with the high frequency of univalents in S. ciliatum might be due to the hybrid nature of the taxon. All the three cytotypes of H. benghalensis are polyploids showing abnormal meiosis and reduced pollen fertility.
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  • E. Harrington, E. R. Orton Jr., G. Jelenkovic
    1985 Volume 50 Issue 1 Pages 9-19
    Published: March 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Morphology of the pachytene chromosomes was studied in Cornus Florida L. Of the 11 pairs of chromosomes, seven were morphologically identified. The major features by which the chromosomes were distinguished are chromosome length, arm length, position of the centromere and distributional pattern of the heterochromatic chromomeres. Identification of the remaining four chromosomes was difficult, due to their similar length and lack of differential morphological markers. A general feature of the genome is an abundance of heterochromatic material which is distributed mainly around the centromere and the distal portion of the short arm. The genome is karyotypically asymmetric. Two pairs of chromosomes participate in the organization of a single nucleolus. In addition, a small nucleoluslike body associated with an interstitial segment of a bivalent was observed in most pachytene cells.
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  • L. Labh, B. N. Verma
    1985 Volume 50 Issue 1 Pages 21-24
    Published: March 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
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  • B. N. Verma
    1985 Volume 50 Issue 1 Pages 25-30
    Published: March 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
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  • M. Munian, D. Subramanian
    1985 Volume 50 Issue 1 Pages 31-37
    Published: March 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Karyotypic analysis of sixteen cultivars of Phaseolus acutifolius A. Gray showed reasonable differences between the cultivars on chromosome length, position of primary constriction and in TF%. Only in two cultivars, a pair of chromosomes was secondarily constricted and most of the chomosomes in all the cultivars, excepting the Nebraska cultivar, possess mostly medianly constricted chromosomes. In Nebraska cultivar, there are 4 pairs of secondary constricted chromosomes and most of the chromosomes possess submedian primary constrictions. An average karyotype of Phaseolus acutifolius has been suggested basing in the results included herewith.
    The observation of TF% ranging from 34.50 to 38.79 revealed a symmetrical karyotypes for 10 cultivars. The others 6 cultivars were observed to be asymmetrical with TF ranging from 30.45 to 33.74. The importance of karyotypic differences in evolution of varieties within a species has been discussed.
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  • C. K. Rudramuniyappa, B. G. Annigeri
    1985 Volume 50 Issue 1 Pages 39-48
    Published: March 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The histochemical constitution and relationship between the sporogenous tissue and tapetum in the anther of Euphorbia pulcherrima Wilid. is studied. The substances localized are insoluble carbohydrates, RNA and proteins. The sporogenous tissue until it differentiates into PMCs, stores abundant PAS positive grains. This is a distinctive and a rare feature. RNA and proteins are also high in it. In PMCs all these substances reduce to low level in the cytoplasm. From microspore stage to mature pollen consistent increase in RNA and proteins is seen. But the PAS positive grains are noticed only for a short period in the freed spores and they are again accumulate when pollen matures. The differentiation and chemical nature of orbicular bodies based on azure B stain in the tapetum is given.
    Orbicules from the beginning to end exhibit green colour. Therefore, they are These chemically similar to pollen wall. Extensive deposition of PAS positive callose thickening around the PMCs and its persistence until meiosis is noticed. The probable implications of all these events are discussed in relation of male gametophyte development.
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  • B. N. Verma
    1985 Volume 50 Issue 1 Pages 49-53
    Published: March 25, 1985
    Released: March 19, 2009
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  • L. Labh, B. N. Verma
    1985 Volume 50 Issue 1 Pages 55-58
    Published: March 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
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  • R. N. Singh, S. K. Roy
    1985 Volume 50 Issue 1 Pages 59-68
    Published: March 25, 1985
    Released: March 19, 2009
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    Dodecaploid (12x) Solanum nigrum attained the highest level of ploidy in this genus with the help of colchicine. Cytomorphological studies have shown the colchiploid to have reduced height but larger, leathery leaves with broader stomata. The berries were bigger with larger and more numerous seeds in them. Pollen were bigger yet mostly fertile (85%). The induced dodecaploid (12x) plant showed diploid like meiosis which was unexpected at such a high level of autoploidy.
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  • O. Aniel Kumar, K. G. Raja Rao
    1985 Volume 50 Issue 1 Pages 69-73
    Published: March 25, 1985
    Released: March 19, 2009
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    In a population of Capsicum frutescens cultivar Tabasco one desynaptic plant was isolated. Meiotic studies in the normal and the desynaptic showed reduced chiasma frequency and pollen fertility in the desynaptic. Chromosome paring at pachytene was normal and complete in the normal sibs. While it was partial in the desynaptic. Twelve bivalents were regularly formed both at diakinesis and metaphase I in the normal, while univalents ranging from 12-24 were recorded at the corresponding stages in the desynaptic. At anaphase I the chromosome segregation was regular (12:12) in the normal sibs and irregular in the desynaptic. It is presumed that desynapsis in Capsicum frutescens may have been due to a spontaneous gene mutation.
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  • Soryu Nishibayashi, Tsuneyoshi Kuroiwa
    1985 Volume 50 Issue 1 Pages 75-82
    Published: March 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The division of mitochnodrial nuclei in Amoeba proteus, Paramecium caudatum, Nitella flexilis and Allium cepa was investigated using 4'-6-diamidino-2-phenylindole (DAPI) epifluorescent microscopy. The mitochondria each contained one mt-nucleus in Amoeba proteus and Paramecium caudatum and one or two mt-nuclei in Nitella flexilis and Allium cepa. The ratio of fluorescent intensity (grain density of negative film) among one DNA molecule of a T4 phage particle and mt-nuclei of spherical mitochondria in Physarum polycepaalum, Amoeba proteus, Paramecium caudatum, Nitella flexilis and Allium cepa was about 1:16:22:5:0.4:0.4. That is, the mitochondrial DNA content in Nitella flexilis and Allium cepa was much smaller than those in Amoeba proteus and Paramecium caudatum. The mitochondria and their nuclei in Amoeba proteus and Paramecium caudatum as well as Physarum polycephalum divided simultaneously by constriction, while segregation of mitochondria) nuclei occurred before the mitochondrial division in Nitella flexilis and Allium cepa. The fluorescent intensity of mt-nuclei in dumbbell-shaped mitochondria of Paramecium caudatum and Allium cepa was about twice that in spherical mitochondria. Therefore, mitochondrial DNA probably duplicated and divided equally into daughter mitochondria.
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  • V. P. Patil, A. S. Jadhav
    1985 Volume 50 Issue 1 Pages 83-88
    Published: March 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Karyomorphology of Thompson Seedless, Kalisahebi and Anab-e-shahi has been studied. Most of the chromosomes were having median or submedian constriction and their lengths range from 0.975 to 2.450 microns. Only one SAT-chromosome was observed in the haploid complement of these varieties. In addition, secondary constriction was noted in the long-arm of the biggest chromosome in Thompson Seedless and Kalisahebi. These results have been discussed in the light of earlier reports.
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  • Maria Teresa Schifino, Carla C. Zanella, Rejone Gus
    1985 Volume 50 Issue 1 Pages 89-99
    Published: March 25, 1985
    Released: March 19, 2009
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    Chromosome numbers and meiotic behavior were studied in two groups of plants selected in a breeding programme of Phalaris, which differed in forage yield, degree of palatability, alkaloid content and flowering time. One of them, with most if not all plants of P. aquatica, had 2n=28 chromosomes and a mainly regular meiosis, the meiotic index ranging from 76.4% to 99.5%. The other, with individuals resembling P. aquatica, P. arundinacea and intermediates between the two, had extremely irregular meiotic behavior (univalents, bivalents, stickiness, bridges, laggards, micronuclei), the meiotic index varying from 3.7% to 55.1%. The PMC chromosome number ranged from 2n=28 to 2n=38. A larger variation in root-tip chromosomes (2n=15-66) as well as evidences of somatic mosaicism were also verified. The hybrid origin of these chromosomally unstable plants was suggested. Chromosome aberrations and aneuploidy have been previously described in these species and their hybrids, but not in such an extreme degree.
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  • Amal K. Biswas, Animesh K. Datta
    1985 Volume 50 Issue 1 Pages 101-107
    Published: March 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Two morphological variants (P-11/2/2 and P-9/2/3) showing translocation were isolated in an EMS treated M1 population of Nigella damascena L. The plant P-11/2/2 exhibited complex chromosomal translocations forming ring of four, six and twelve chromosomes and chain of four and six chromosomes, while the plant P-9/2/3 manifested interchange involving four chromosomes in chain configruation only. Possibly, multiple translocation observed in the plant P-l 1/2/2 has resulted in complete pollen and seed sterility following unbalanced microspore formation and concomitant disturbances in fertilization. On the contrary, 78.64% pollen and total seed sterility noted in the plant P-9/2/3 may be ascribed to changes in the genomic balance or physiological disturbances as a consequence of chromosomal interchanges induced by the mutagen or can be attributed to defective female gametogenesis.
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  • Masanobu Kitami
    1985 Volume 50 Issue 1 Pages 109-115
    Published: March 25, 1985
    Released: March 19, 2009
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  • R. C. Gupta, B. S. Gill
    1985 Volume 50 Issue 1 Pages 117-123
    Published: March 25, 1985
    Released: March 19, 2009
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    Cytogenetical studies were carried out in colchicine induced autotetraploids of Chrysanthemum coronarium. Autotetraploids are found to be inferior and do not show any increase in size of its parts. Meiosis is characterised by multiple associations ranging from octavalent to univalents. There is moderate frequency of multivalent formation. Though there is tendency for normal distribution at A-I and high pollen fertility, viable achenes are not produced.
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  • A. Sadanandam, K. Subhash
    1985 Volume 50 Issue 1 Pages 125-128
    Published: March 25, 1985
    Released: March 19, 2009
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    An aneuploid of Capsicum was isolated from Pusa Jwala variety following 40 kR gamma irradiation. The variant was sufficiently vigorous, darkgreen and sterile. On cytological examination the plant was found to be a multiple trisomic for 7 chromosomes. Meiosis in the aneuploid was highly irregular, the spectrum of anomalies noticed included various associations of chromosomes at diakinesis, lagging chromosomes at anaphase; appearacne of micronuclei at telophase II and microspores with different constitutions of micronuclei.
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  • R. K. Somashekar, M. R. Gurudev, Sidda Ramiah
    1985 Volume 50 Issue 1 Pages 129-134
    Published: March 25, 1985
    Released: March 19, 2009
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    Cytological effects of dyes manufacturing industry waste water on root meristematic cells of Allium cepa were investigated. The results obtained showed that the effluents induce various types of abnormalities such as chromosome breaks, C-mitosis, binucleate cells, tri- and terta-polar cells, nuclear cleavage, etc. It is concluded that waste waters of industrial origin not only upset the balance in aquatic ecosystem but also considerable genetic impact on plants.
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  • Preeti Pandey, Smita Banerjee
    1985 Volume 50 Issue 1 Pages 135-145
    Published: March 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Newly moulted adult male P. pictus were injected with various doses of .2%, 1% and saturated apholate solution in double distilled water. The spermatocyte chromosomes were studied for aberrations induced by apholate at various time intervals. The aberrations were found to be of two types: (a) gross or nucleotoxic and (b) individual chromosomal aberrations as described in the paper. Mostly the aberrations manifested themselves between 24-72 hours, killing some spermatocytes and incapacitating others. The mode of action of apholate in the induction of chromosome aberrations are discussed. It is assumed that apholate acts in both direct and indirect pathways which are discussed.
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  • Dipak Kumar Kar, Sumitra Sen
    1985 Volume 50 Issue 1 Pages 147-155
    Published: March 25, 1985
    Released: March 19, 2009
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    Chromosome analysis of seven species of Asparagus and four populations of A. racemosus has revealed that both polyploidy (20, 40, 60) and structural alterations have played a role in speciation of Asparagus associated with variation in sapogenin content.
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  • J. E. Thomas, D. Davidson
    1985 Volume 50 Issue 1 Pages 157-166
    Published: March 25, 1985
    Released: March 19, 2009
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    Total protein content and area of nuclei were determined for cells of the primary root of Vicia faba during the first 144 hours following the onset of imbibition. We wished to determine what change, if any, occurs in protein contents of nuclei as meristematic cells move from a dormant into a proliferative condition. Nuclear proteins were stained with dinitrofluorobenzene and protein content, in arbitrary units, was determined by microspectrophotometry. In the first 50 hours mean protein content of nuclei increase; this, as we have shown, is the period in which cells and nuclei increase in size as they complete their first cell cycle. During subsequent cell cycles, cell area decreases markedly, nuclear area decreases to a lesser extent; accompanying these decreases, the mean and the range of protein contents of nuclei decreased significantly. Thus, as the proliferating population of cells of a root meristem becomes steady-state, there is an absolute decrease in the concentration of total proteins within the nucleus. This was revealed particularly clearly by comparing unclei of identical areas from roots of different ages. Increases in nuclear size were induced by treatment with 5-aminouracil for upto 24 hours: this did not result in a significant increase in protein content of nuclei. These results agree with those from untreated roots that area and protein content of nuclei can, to a considerable extent, vary independently of one another.
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  • S. K. Gupta, S. K. Roy
    1985 Volume 50 Issue 1 Pages 167-175
    Published: March 25, 1985
    Released: March 19, 2009
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    Radiosensitivity of a diploid (P. ixocarpa) and a tetraploid (P. peruviana) species of Physalis has been studied. Meiotic abnormalities induced by gammarays were compared in both species and found that it was always greater in tetraploid than in diploid species at each corresponding dose. The tetraploid plant due to greater chromosomal volume is more vulnerable to radiation hits and its immediate consequences are expected to contribute to the formation of sterile pollen, but this defect could be overcome by the buffering action of the unaltered genes over the altered ones at multiple loci, which normalizes the induced plant sterility. The diploid P. ixocarpa exhibited higher radiosensitivity than the tetraploid P. peruviana.
    Comparison between the frequencies of meiotic anomalies of M2 and M1 indicated that the latter has exaggerated values on these at all exposure levels. The lowered values of M2 indicated their elimination through diplontic selection or intrasomatic or competitive elimination during the course of time lapse.
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  • U. C. Lavania
    1985 Volume 50 Issue 1 Pages 177-185
    Published: March 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The details of chromosome morphology and nuclear DNA amount (2C value) in 20 different collections in Vetiveria zizanioides are presented. All the collections reveal the somatic chromosome no.=20. In general, the karyotypes are nearly symmetrical with chromosomes having median -to- submedian centromeres, in all the cases. However, variations are noticeable in various collections with respect to chromosome size and nuclear DNA content. The total haploid chromatin length varies from 25.6μm-38.7μm and 2C value from 2.02 pico gms.-2.56 pico gms. The qualitative and quantitative variation in karyological features may possibly account for qualitative and quantitative variation in oil content/composition in the various collections. Further, the somatic chromosomes in one of the collections have also been analysed for Giemsa C-banding patterns to elucidate the finer details of chromosome organisation for characterising the individual chromosomes. The chromosome nos. 1, 2 and 3, have prominent centromeric and terminal bands on long arms, nos. 4, 5 and 6 possess distinct procentric bands and nos. 7, 8, 9 and 10 are with one terminal band each on one arm except no. 8 where the terminal bands are present on both arms. The importance of such an study in hybrid identification is stressed.
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  • I. Mitotic effects
    Parmjit Kaur, I. S. Grover
    1985 Volume 50 Issue 1 Pages 187-197
    Published: March 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The mitotic effects of eight organophosphorus pesticides (anthio, diazinon, dursban, ekalux, methylparathion, phendal, rogor and sumithion) and MNNG (N-methyl-N'-nitro-N-nitrosoguanidine) were studied in barley (Hordeum vulgare L.). The chromo/cytotoxic effects included fragments, ring chromosomes and C-mitotic configurations at metaphase. Chromatin bridges, laggards and multipolar cells were observed at anaphase. The dose-response curves were found to be positively correlated in all the pesticides.
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  • II. Meiotic effects
    Parmjit Kaur, I. S. Grover
    1985 Volume 50 Issue 1 Pages 199-211
    Published: March 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The meiotic effects of eight organophosphorus pesticides (anthio, diazinon, dursban, ekalux, methylparathion, phendal, rogor and sumithion) were studied in barley (Hordeum vulgare L. CV. C164). Seed soak as well as spray treatments were conducted. Critical analysis of pollen mother cells (PMCs) of treated plants revealed chromosomal aberrations including multivalents and univalents, stickiness and despiralization at metaphase-I whereas chromatin bridges, lagging chromosomes and mis/non-orientation of chromosomes were observed at anaphase-I. The cyto/chromotoxic effects as observed by spraying the plants with various pesticides were same as above. However, the frequency of aberrant PMCs was comparatively less as compared to that of seed treated plants. The statistical analysis revealed that dose-response curve was linear and there existed a positive correlation between the concentration of the pesticide and the aberrations.
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