CYTOLOGIA
Online ISSN : 1348-7019
Print ISSN : 0011-4545
Volume 24, Issue 3
Displaying 1-13 of 13 articles from this issue
  • IV. Subtribe Sorgheae
    Robert P. Celarier
    1959 Volume 24 Issue 3 Pages 285-303
    Published: November 25, 1959
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    1. A review of the cytology of the Sorgheae (excluding Sorghum) is presented. Chromosome behavior at meiosis is discussed whenever available.
    2. An artificial key is given for the eight genera. All but two have been studied cytologically and these are both monotypic. One is the primitive Lasiorrhachis and the other the very specialized Asthenochloa.
    3. Of the eighteen species reported, seven are studied meiotically for the first time.
    4. Five is concluded to be the most likely basic chromosome number for the subtribe, but one species (Cleistachne sorghoides) is 2n=36 and is considered to have a basic number of nine.
    5. Although polyploidy is common it seems to be less frequent than in other subtribes.
    6. Noticable differences in chromosome size are seen in different genera and subgenera but their relationship to phylogeny is not certain.
    7. A discussion of the phylogenetic patterns of the subtribe is presented. In general these patterns are rather direct with what appears to be two distinct lines of development. However, there are several suggestions of interconnections between these lines that need additional study.
    8. It is suggested that the time is ripe for detailed hybridization studies between species within the different genera, between the subgenera in Sorghum, between selected genera, and in a few cases between subtribes.
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  • T. N. Khoshoo, V. B. Sharma
    1959 Volume 24 Issue 3 Pages 304-314
    Published: November 25, 1959
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    The present population is pentaploid with seven as the basic number. The karyotype shows that all the chromosomes are median or submedian. However, four submedian chromosomes have their smaller arms, rather shorter than the smaller arms of the remaining submedian chromosomes. Two of these have an exaggerated centromere and have a secondary constriction located very near it. The karyotype can be relegated into two sets of 14 chromosomes each, and another set of 7 chromosomes.
    At meiosis pentavalents to univalents are organized. Higher associations occur in a lower frequency, The maximum number of bivalents is 14, which are accompanied by 7 univalents.
    At anaphase-I unequal distribution is common. The number at a pole varies from 14 to 21. Lagging and misdividing univalents, telocentrics, bridges with and without fragments are present.
    On average 29.6 chromosomes pair at metaphase-I, while 5.4 remain as univalents. This point, coupled with the karyotypic evidence, makes it reasonably clear that there are probably two sets of 14 fairly homologous chromosomes plus 7 other chromosomes. In the former two sets, there are small portions that are homologous, which fact accounts for the low multivalent frequency. It appears that this race is a segmental-allopentaploid (AA AIAI B). On the basis of the comparative evidence from the karyotypes, it is proposed that this pentaploid race probably arose as a hybrid between triploid and tetraploid races in which unreduced gametes of former were involved.
    The seeds appear to be inviable but the race is perpetuated by production of 8-10 bulbs by each individual.
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  • David Pittman
    1959 Volume 24 Issue 3 Pages 315-325
    Published: November 25, 1959
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    Ultraviolet radiation induces respiration-deficient variants with high frequency in both haploid and tetraploid yeasts. Variant colonies arising after irradiation, when overlaid with triphenyl tetrazolium chloride agar, can be classified as (1) “whole colony” and (2) “variegated or sectored.” The heterogeneity in respiratory phenotype of the latter type of colonies is not detectable by colony morphology prior to overlaying with tetrazolium agar. The variegated types may explain some cases of “reversion” of respirationdeficient cells to wild type. Whole colony variants can be grouped into two classes (vI and vII). The vI variants are similar to spontaneously occurring variants and fail to revert to wild type, whereas the vII variants generally revert to wild type at a low frequency. The vI type is produced most frequently and presumably results from nongenic radiation damage, while the less frequently occurring vI type results from nuclear damage.
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  • S. K. Jain
    1959 Volume 24 Issue 3 Pages 326-329
    Published: November 25, 1959
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
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  • VIII. Isolating mechanisms
    T. N. Khoshoo
    1959 Volume 24 Issue 3 Pages 330-334
    Published: November 25, 1959
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    There are three isolating mechanisms in this complex, which in some races are superimposed one upon the other. These are, ecological preferences of the various races, self-pollination and seed failure after pollinations involving races with different chromosome number.
    Some races are ecologically isolated, and on this basis the entire complex can be divided into three categories, Evidently there is a greater possibility of hybrids being formed among the races occupying the same habitat. However, out-crossing is prevented because of the obligate self-pollination in this complex. Only one type of hybrid (3×) arises in nature or has been obtained after crossing the various natural entities. In nature this hybrid arises through the production of protogynous flowers by the diploid, because such flowers are cross-pollinated by flies with the pollen of the tetraploid. Due to the malfunction of endosperm, all the other expected and unexpected hybrids among parents differing in chromosome number fail. This results in the production of only small, deformed and shrivelled seeds, which are ordinarily inviable. The barrier to crossability fails when homoploid races, irrespective of their genomic constitution, are crossed.
    The triploid hybrid does not break the isolation between its parents, because it is so sterile that it has given rise to a new race, hexaploid, which again is isolated from its progenitors.
    The races within this complex are, as yet ‘genetic’ species, because so far morphologically these are not very strongly differentiated.
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  • B. R. Seshachar, S. R. Venkatasubba Rao, C. M. S. Dass
    1959 Volume 24 Issue 3 Pages 335-341
    Published: November 25, 1959
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    Evidence from irradiation experiments in Eurybrachis apicalis (Homoptera: Auchenorrhyncha: Eurybrachidae) leads to the conclusion that in this species, the chromosomes are monocentric. Chromosome fragments produced by X-ray irradiation do not segregate to the poles either in mitotis or meiosis, and are left behind and lost in the cytoplasm. It is probable, however, that a variety of conditions prevail in the Hemiptera, and both localized and ‘diffuse’ kinetochore activity occurs in members of the group.
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  • V. Chromosome numbers in Saccharum, Erianthus, Narenga, and Sclerostachya from Thailand and Vietnam
    Sam Price
    1959 Volume 24 Issue 3 Pages 342-347
    Published: November 25, 1959
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    Grasses from Thailand closely related to sugarcane have the following chromosome numbers: In Saccharum spontaneum L. 2n=78, 80 and 96. Aneuploid individuals occur in each type. Two plants among 96-chromosome collections have 88 chromosomes and could be hybrids between 96- and 80- chromosome types. In Erianthus arundinaceus (Retz.) Jesw. 2n=60. In Narenga porphyrocoma (Hance) Bor 2n=30. In a species of Sclerostachya not yet described, 2n=30.
    Grasses from Vietnam related to sugarcane have the following chromosome numbers: In Saccharum spontaneum 2n=80, and in Erianthus bengalense (Retz.) Stewart 2n=60.
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  • Yasushi Ohnuki
    1959 Volume 24 Issue 3 Pages 348-357
    Published: November 25, 1959
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    The morphology and structure of living eggs of the golden hamster were observed by phase contrast microscopy. The present preliminary communication reports the morphological and structural changes of eggs in the course of maturation, fertilization and early cleavage.
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  • R. S. Chopra, N. N. Bhandari
    1959 Volume 24 Issue 3 Pages 358-366
    Published: November 25, 1959
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    1. Cytology of 4 species of Atrichum Palis has been studied. A. flavisetum and A. pallidum (both dioecious) have seven chromosomes each, while A. subserratum and A. obtusulum (which includes A. sub-obtusulum of C. Muller) both monoecious have 14 chromosomes each.
    2. Difference in the sexuality of A. flavisetum and A. subserratum between what we have noted and Brotherus has recorded, indicate that a monoecious race of the former and a dioecious race of the latter may be expected to grow in this area or near it.
    3. A. subserratum may have been produced by hybridization between A. flavisetum (recorded) and A. subserratum (diploid expected race) or by auto-polyploidy of the latter.
    4. A. obtusulum may be the hybrid between a diploid like A. subserratum expected, but differing from it in having “m” chromosome and A. pallidum.
    5. A search is being made for the expected “races” and species. Further work on the cytology of this group or plexus of species is in hand.
    Our sincerest thanks are due to Prof. P. N. Mehra for providing facilities, which enabled us to carry on this work, to Shri T. N. Khoshoo for going through the manuscript, Shri R. S. Pathania for the microphotographs and Mr. A. H. Norkett for the determination of the species of Atrichum.
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  • Toshihide Tabata
    1959 Volume 24 Issue 3 Pages 367-377
    Published: November 25, 1959
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    A chromosome survey was made in the following human malignant tumors in vivo; sixteen gastric cancers, five maxillary cancers, four laryngeal cancers, two penis cancers and four reticulosarcomas.
    Evidence was presented that in each tumor stem-cells are present with a characteristic range and mode of chromosome numbers and a particular idiogram by which the tumor is clearly distinguishable from other tumors, as well as from the ordinary tissue. The stemline chromosome numbers show a wide variation ranging from hypodiploid to hypertetraploid.
    It was shown that most of the chromosomes of neoplastic cells differ in shape and/or size from those of normal cells; it is assumed that in tumor chromosomes considerable structural and mutational changes must have occurred probably correlated with the neoplastic condition.
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  • Singo Nakazawa, Akira Tsusaka
    1959 Volume 24 Issue 3 Pages 378-388
    Published: November 25, 1959
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    1. When rhizoid is differentiated from the protonema of some ferns, Dryopteris varia, Diplazium japonicum, and Blechnum niponicum a special cytoplasm which has a high affinity for metallic ions, called the “metallophilic cytoplasm”, appears at the presumptive part prior to the actual differentiation as a prepattern to the rhizoid formation.
    2. In the rhizoid under active elongation, the metallophilic cytoplasm appears in the basal region while in a fullgrown rhizoid it is restricted to the basal end.
    3. The metallophilic cytoplasm could not be verified in rhizoids of the sporeling of a moss, Pogonatum inflexum, in root hairs of the seedling of some Angiosperm, Glycine Max, Raphanus sativus, and Triticum vulgare. 4. The metallophilic property appears regardless of the acidity level of the cytoplasm whether it is on the lower or on the higher side of its IEP. Therefore, it seems that it cannot be attributed to the attraction by the cytoplasm of metallic ions caused by difference in electric charge between the two.
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  • Arun Kumar Sharma, Praphulla Chandra Datta
    1959 Volume 24 Issue 3 Pages 389-402
    Published: November 25, 1959
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    In order to find out how far karyotypic changes or undetectable gene mutations have been associated with the origin of different varieties of Lathyrus odoratus, which differ in flower colour, leaf nature, tendril character etc., a thorough analysis of the karyotype of different pure varieties of L. odoratus have been carried out in the present investigation. For this purpose a new improved method involving pre-treatment with paradichlorobenzene was employed and the procedure for all the strains had been kept constant.
    It has been revealed, that in spite of a homogeneity amongst all the strains, each strain is characterised by its own karyotype. They mainly differ with respect to the number and position of constriction regions in chromosomes. All these facts suggest that the structural changes of chromosomes have always been associated with the evolution of different varieties.
    Regular meiosis noticed in these strains can be explained by assuming that through extensive cultivation and selection all the structural alterations have attained a state of homozygosity.
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  • Earl H. Newcomer
    1959 Volume 24 Issue 3 Pages 403-410
    Published: November 25, 1959
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
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