CYTOLOGIA
Online ISSN : 1348-7019
Print ISSN : 0011-4545
Volume 37, Issue 1
Displaying 1-14 of 14 articles from this issue
  • R. J. Low, K. Benirschke
    1972 Volume 37 Issue 1 Pages 1-11
    Published: March 25, 1972
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    Studies of the chromosomes of a domesticated and five wild red foxes, Vulpes fulva, have produced chromosome counts of 35, 36, 37 and 38. Karyotypic analyses revealed that variations in the number of microchromosomes produced this polymorphism; moreover, it is suggested that these microchromosomes may arise from fragmentation of the macrochromosomes. Because it has not been possible to establish a consistent chromosome count for this species, it is further suggested that 2n=34 be used to describe the basic diploid count and that the number of microchromosomes present be added to this figure. Thus, a total chromosome count of 36 would, by the suggested system, be recorded as 2n=34+2m.
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  • I. Tribe Scirpeae
    Bhupendranath Sanyal, Archana Sharma
    1972 Volume 37 Issue 1 Pages 13-32
    Published: March 25, 1972
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    Cytotaxonomical studies have been carried out on 30 species and varieties under 4 genera belonging to the tribe Scirpeae, as part of a programme of investigation of Indian representatives of the family Cyperaceae with the aid of suitable schedules. Detailed karyotype analysis shows a general resemblance of the chromosome morphology, testifying to the homogeneity of the group as a whole. The genus Fimbristylis has been found to represent a very primitive level of evolution as compared to the genus Eleocharis. On the basis of evidences, it has been pointed out that possibly the evolution from diffuse to localised centromere has been achieved in a short step, since both types of centromere have been recorded in the species of Scirpus and Eleocharis.
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  • II. Tribe Cypereae
    Bhupendranath Sanyal
    1972 Volume 37 Issue 1 Pages 33-42
    Published: March 25, 1972
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    The structure and behaviour of chromosomes of sixteen species belonging to three genera (Cyperus, Kyllinga and Pycreus) of the tribe Cypereae under the family Cyperaceae have been studied. Taxonomic status of the genera was dealt with in the light of cytological findings. Cytoecological correlation has been made. The advanced status of the genus Cyperus of the tribe Cypereae has been indicated. The advanced status of the tribe Cypereae of Hutchinson (1959) as compared to that of the tribe Scirpeae has been dis-cussed. The question of giving them subtribe status in the tribe Scirpeae of Pax has been also suggested. The probability of the origin of the family through Juncales from Liliaceae as adopted by Hutchinson (1959) has been supported.
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  • D. N. Vishnoi
    1972 Volume 37 Issue 1 Pages 43-51
    Published: March 25, 1972
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    1. The structure and behaviour of mitotic and meiotic chromosomes in ten species of Indian Decapod Crustaceans (belonging to 6 different families) have been investigated.
    2. The Indian Scylla serrata is genetically a different species from the Japanese Scylla serrata-the diploid number in the latter is higher by as many as 12 chromosomes than that of the former.
    3. In the Macruran, Palaemon lamarrei, and in nine other Brachyurans the sex chromosomes are cytologically indistinguishable.
    4. The pathways of chromosomal evolution in related groups of Decapod Crustacea have been discussed.
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  • P. N. Mehra, L. S. Gill
    1972 Volume 37 Issue 1 Pages 53-57
    Published: March 25, 1972
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    Chromosome counts for 6 species have been made available for the first time. The species are: Orthosiphon pallidus (n=14); Plectranthus ternifolius (n=12); P. striatus (n=12); P. coetsa (n=12); P. rugosus (n=12); and P. gerardianus (n=12). The base number in each genus have been discussed.
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  • Charles H. Uhl, Reid Moran
    1972 Volume 37 Issue 1 Pages 59-81
    Published: March 25, 1972
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    Chromosome numbers are reported for 257 collections, representing all but about five of the approximately 35 species of Crassulaceae native to Japan and South Korea, 21 of them for the first time. These species differ considerably among themselves in their chromosomes: in number, in size, and in the constancy or variation within species. A higher proportion of triploids and other odd-ploids has been found than is known in the family elsewhere, usually accompanied by obvious adaptations for vegetative propagation. Several species or species complexes that vary greatly in their morphology have been found to vary also in their chromosomes; but not enough is known about them yet to propose new ways of classifying them. Rough measurements of nuclear volume support the conclusion that members of two species complexes differ in the types of chromosome change predominating in their evolution, polyploidy in S. Sect. Aizoon and structural chromosomal rearrangements in S. polytrichoides sensu latiore.
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  • V. Ranga Rao, B. R. Murty
    1972 Volume 37 Issue 1 Pages 83-93
    Published: March 25, 1972
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    Combining ability analyses were made for average chiasma frequency, pollen mother cell and bivalent variances for chiasma frequency from a fractional diallel set involving seventeen varieties of Triticum aestivum L.
    Varieties differed significantly in their means for average chiasma frequency and its associated variances. Mean chiasma frequency in F1's exhibited a decline over that of parents. Heterosis was positive for pollen mother cell variance and negative for bivalent variance. The fractional diallel analysis of combining ability indicated predominantly nonadditive gene action for chiasma frequency and its variances attributable to pollen mother cell and bivalent. Pronounced complementary epistasis was indicated for chiasma frequency while both duplicate and complementary epistasis appeared to be equally important for the variances. From the occurrence of high chiasma frequency in some varieties and low chiasma fre-quency in others it was concluded that chromosomal mechanism counteracts the restrictive effects of the breeding system in the former and reinforces in the latter. Genotypic control of chiasma frequency at plant, pollen mother cell and bivalent level with a compensatory mechanism between the different levels was also indicated. The role of cytological restriction of recombination in the conservation of variability, exploitation of additive and nonadditive components of genetic variance and its implications in adaptation are discussed.
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  • J. F. Mesquita
    1972 Volume 37 Issue 1 Pages 95-110
    Published: March 25, 1972
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    Des phémomènes d'autodigestion cellulaire ont été décrits très souvent dans la cellule animale. Généralement ils sont en rapport avec l'activité de structures spécialisées, les cytolisomes ou vacuoles autophagiques. Cependant, dans la cellule végétale les références á l'existence de formations analogues à celles-ci sont plus rares.
    Au cours de l'étude ultrastructurale des racines de l'Allium cepa et du Lupinus albus, on a trouvé, outre les éléments normales du vacuome d'autres. types de vacuoles comparables aux vacuoles autophagiques frequemment observés dans la cellule animale, en des conditions normales ou pathologiques. Les vacuoles typiques, après fixation par le glutaraldéhyde-postosmié, se présentent vides ou contenant un precipité dense à structure finement granuleuse fibrillaire.
    Les autres vacuoles montrent un contenu beaucoup plus dense et hétérogène, qui pent se présenter, soit amorphe, soit formé par des granules à l'aspect ribosomale, ou bien organisé en structures multilamellaires.
    Parfois, ces vacuoles renferment des débris cellulaires, où il est encore possible de reconnaître quelques organites (mitochondries, corps de Golgi) plus ou moins dégénérescents. Alors, elles ressemblent les vacuoles autophagiques ou cytolisomes de la cellule animale. Le reticulum endoplasmique lisse semble jouer un rôle très important dans la formation de ces vacuoles autophagiques.
    La fonction probable de ces structures est finalement discutée, en rapport avec les découvertes récentes dans le domain de la biochimie et de la cytochimie végétales.
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  • A. N. Rao, S. C. Chin
    1972 Volume 37 Issue 1 Pages 111-118
    Published: March 25, 1972
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    Seed germination in Melastoma malabathricum was studied under three different conditions in the laboratory. Root hairs were formed acropetally in abundance on the entire root surface extending upto the tip of the root. Size of root hair was determined. Many variations in the root hair morphology were seen like branching, septate condition, swollen and curved hairs. These variations are described and discussed with reference to previous literature.
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  • J. Moutschen, N. Degraeve, B. Monfort
    1972 Volume 37 Issue 1 Pages 119-130
    Published: March 25, 1972
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    The main characters of Rumex acetosa chromosomes were studied at metaphase. The karyotype was divided in four groups:
    Group I contains the sexual chromosome. In male, no distinction could be made between X and Y1 although the chromosome Y2 is morphologically quite different.
    Group II contains two chromosomes, one of which is satellitic.
    Group III contains three chromosomes of different length and arm ratio.
    Group IV contains only one submediocentric chromosome, the smallest of the genome.
    By prometaphase analysis, it was found that the satellitic chromosome is nucleolus organising.
    The differentially stained regions were mapped at prometaphase.
    At prometaphase, the chromosomes were not randomally arranged but end-to-end attachment could be proved. This end-to-end attachment was repeatedly observed between homologous in the direction proximal-distal. It also occurred between non-homologous in the same direction and with definite pattern, the main characters of which could be described.
    Work performed under the auspices of the Çentre de Génétique du Développement chez les Organismes superieurs.
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  • I. Division of endosperm protoplasts of Zephyranthes in vivo and the isolation of the protoplast in vitro
    Tsuneyoshi Niitsu, Akiko Hanaoka
    1972 Volume 37 Issue 1 Pages 131-142
    Published: March 25, 1972
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    1. From the endosperm of Zephyranthes candida in an immature seed 1.7-2.7mm length, endosperm cells have been successfully isolated and cultured in vitro both in an artificial culture medium and also in endosperm fluid.
    2. Histological analysis of the endosperm development investigated immediately after pollination revealed that each mitotic nucleus is embedded in its own protoplast without being enveloped in a cellulose cell wall. When the endosperm cavity is filled with naked protoplasts, the cellulose cell walls develop centripetally along the protoplast surface from the peripheral region to the central part of the seed tissue.
    3. The behavior of chromosomes and spindles was investigated in the mitosis of isolated endosperm protoplasts which were freely suspended in vitro. From the result of in vivo observation on the continuous changes of mitosis in cultured protoplasts, it is confirmed that the spindle body is nuclear in origin and a system independent of the cytoplasm. This fact is also observed in fixed cells treated with modified Navashin's solution which is specific for the preservation of the atractoplasm, spindle substance and especially chromosomal fibers.
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  • II. Effects of cycloheximide upon the development of kinetochore fibers studied in the pollen mitosis of Ornithogalum virens in vivo
    Tsuneyoshi Niitsu, Akio Hanaoka, Kazuko Uchiyama
    1972 Volume 37 Issue 1 Pages 143-154
    Published: March 25, 1972
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    By applying the synchronous mitotic cycle in the pollen grains of Ornithogalum virens (n=3) cultured in vitro, the effect of cycloheximide on the kinetochore fiber development has been studied morphologically as well as quantitatively.
    1. Cycloheximide of 1 ppm did not suppress mitosis completely but a delay in the mitotic process appeared, especially when entering metaphase.
    2. The arrested mitotic cells prior to metaphase will enter mitotic activity with the termination of the cycloheximide treatment. Their delay in entering metaphase corresponded exactly to the duration time of the cycloheximide treatment during which period the kinetochore fiber development and the sister kinetochore separation had been suppressed. The chromosomes at arrested metaphase showed skipairs.
    3. The mitotic cells in anaphase at the beginning of the treatment showed no effect of the drug and proceeded normally to further mitotic stages.
    4. By the suppression of the kinetochore fiber development by cycloheximide treatment, the kinetochore substance may be confirmed to be a kind of protein which is synthesized at the kinetochore site in prometaphase.
    5. The quantitative analysis of both the frequency curves and also of the duration time of the mitotic stages indicate the absence of kinetochore fiber in prometaphase. These were generally believed to be present in fixed preparations.
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  • B. T. Roach
    1972 Volume 37 Issue 1 Pages 155-161
    Published: March 25, 1972
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    Chromosome numbers of nine clones of S. edule are reported. Six of the clones were found to have 2n=70 chromosomes and two had 2n=80 chromosomes. The remaining clone was found to have 2n=60 chromosomes, this being the first reported instance of this chromosome number in S. edule.
    The cytological complexity in this species, suggested by earlier chromosome counts, may be incorrect. S. edule probably consists basically of a simple polyploid series, with occasional aneuploids.
    The probable origin of this species is discussed. It seems possible that the clones presently recognised as S. edule may have resulted from intergeneric hybridisation.
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  • Duvall A. Jones
    1972 Volume 37 Issue 1 Pages 163-167
    Published: March 25, 1972
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    An unusual type of spermiogenesis is described from the ectoproct Conopeum commensale. The sperm cell and its flagellum appear to develop in a coiled position within the spermatid membrane. After the thick-bodied sperm is freed from the membrane, it uncoils. This form of spermiogenesis has not been recorded among ectoprocts or other animals.
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