CYTOLOGIA
Online ISSN : 1348-7019
Print ISSN : 0011-4545
Volume 46 , Issue 3
Showing 1-17 articles out of 17 articles from the selected issue
  • G. Allan Edwards, Paul A. Fryxell
    1981 Volume 46 Issue 3 Pages 455-458
    Published: September 25, 1981
    Released: March 19, 2009
    JOURNAL FREE ACCESS
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  • I. Hexaploid Ch. japonense Nakai
    Kuniaki Watanabe
    1981 Volume 46 Issue 3 Pages 459-498
    Published: September 25, 1981
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1) In meiosis of Ch. japonense (Saka strain) 2n=6x=54, 27 II was the main chromosome configuration and 1 IV+25 II and 26 II+2 I were rarely observed. Fifty-four chromosomes, at mitotic metaphase, varied in length from 8.4μm to 4.2μm and in arm ratio from 1.0 to 4.9. Ten satellite chromosomes and six small chromosomes with extreme subterminal centromeres were well distinguishable. Karyomorphologically this species is not an autohexaploid.
    2) Eight F1-hybrids between hexaploid Ch. japonense (Saka strain) and diploid Ch. boreale, with 2n=4x=36 and 2n=4x+1=37, were obtained. 2 IV+14 II, 1 IV+16 II and 18 II were the main meiotic configurations in the F1-hybrid with 2n=4x=36. The quadrivalent frequencies conform to the Poisson distribution. The chromosomes derived from Ch.japonense (Saka strain) paired both homoeologously and homologously with the Ch. boreale chromosomes.
    3) F1-hybrids were partially fertile (0%-1.1% in interbreeding and 0.3%-5.9% in intrabreeding) and gave rise to triploid B1-hybrids on backcrossing to diploid Ch. boreale, and to tetraploid F2-hybrids by intrabreeding.
    4) In eight of the nine B1-hybrids with 2n=3x=27 studied the average trivalent formation per PMC ranged from 4.66 to 5.55. The trivalent frequencies conform to the Poisson or binomial distribution. Further homoeologous chromosome associations were revealed in this generation. In the ninth B1-hybrid, 9 II+9 I was the main chromosome configuration. This plant was indiscriminable morphologically from the others.
    5) These B1-hybrids with 2n=3x=27 were partially fertile (0%-0.2% in interbreeding and 0%-3.7% in intrabreeding) and gave rise to B2-hybrids with 2n=24, 26, 27 and 36 on backcrossing to the diploid Ch. boreale, and progenies with 2n=30, 32, 33, 34, 35 and 36 by intrabreeding. In B2-hybrids with 2n=26, the following meiotic configurations were frequently observed; 7 III+2 II+1 I, 6 III+3 II+2 I, 5 III+4 II+3 I, 4 III+5 II+4 I and 3 III+6 II+5 I.
    6) In seven F2-hybrids with 2n=4x=36, the following meiotic configurations were frequently observed; 3 IV+12 II, 2 IV+14 II, 1 IV+16 II and 18 II. There is a significant difference in the frequency of quadrivalent and bivalent formation among F2-hybrids; the maximum number of quadrivalents per PMC varied from four to two. Quadrivalent frequencies conform to the Poisson distribution. The rate of seed setting varied from 0% to 58.7% in F2-hybrid intra-breedings. There was no correlation between the frequency of multivalent formation and the rate of seed setting.
    7) Nineteen of the twenty F3-hybrids studied had the chromosome number 2n=4x=36 and the twentieth had 2n=4x+1=37. In eleven F3-hybrids with 2n=4x=36 the following meiotic configurations were frequently observed; 3 IV+12 II, 2 IV+ 14 II, 1 IV+16 II and 18 II. There was a significant difference in the frequency of quadrivalent and bivalent formation among F3-hybrids; the maximum number of quadrivalents per PMC varied from eight to two. Quadrivalent frequencies conform to the Poisson distribution.
    8) In Ch. japonense (Nakamura strain) with 2n=6x=54, 27 II was the main meiotic configuration and 2 IV+23 II, 1 IV+25 II, 1 IV+24 II+2 I and 26 II+2 I were rarely observed. Fifty-four chromosomes, at mitotic metaphase, varied in length from 6.7μm to 3.8μm and in arm ratio from 1.0 to 4.4. Eight satellite chromosomes and six small chromosomes with extreme subterminal centromeres were well distinguishable. Karyomorphologically this species is not an autohexaploid.
    9) Two F1-hybrids with 2n=4x+1=37 between diploid Ch. boreale and Ch. japonense (Nakamura strain) were obtained by ovary culture.
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  • II. Octoploid Ch. ornatum Hemsley
    Kuniaki Watanabe
    1981 Volume 46 Issue 3 Pages 499-513
    Published: September 25, 1981
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1) In Ch. ornatum (Akune strain) with 2n=8x=72 the following meiotic configurations were frequently observed; 2 IV+32 II, 1 IV+34 II, 36 II and 35 II+2 I. Seventy-two chromosomes at mitotic metaphase varied in length from 5.1μm to 2.8μm and in arm ratio from 1.0 to 6.5. Five satellite chromosomes and seven small chromosomes with the extreme subterminal centromeres were well distinguishable. Karyomorphologically this strain is not an autooctoploid.
    2) One androgenetic polyhaploid with 2n=4x+1=37 was obtained by artificial ovary culture after hybridization with the diploid Ch. Makinoi. The following meiotic configurations were frequently observed; 1 IV+1 III+15 II, 1 IV+1 III+14 II+2 I, 1 IV+16 II+1 I, 1 III+17 II and 18 II+1 I. A pentavalent association and a chromosome fragment were also observed rarely. The chromosomes derived from Ch. ornatum (Akune strain) paired homoeologously. The data of quadrivalent frequency conform to the theoretical Poisson expectation based on the random hypothesis.
    3) In Ch. ornatum (Yakushima Isl. strain) with 2n=8x=72, 36 II was the main meiotic configuration and 3 IV+30 II, 2 IV+32 II, 1 IV+34 II and 35 II+2 I were rarely observed. Seventy-two chromosomes, at mitotic metaphase, varied in length from 6.0μm to 3.2μm and in arm ratio from 1.0 to 4.6. Ten satellites chromosomes and five small chromosomes with extreme subterminal centromers were well distinguishable. Karyomorphologically this strain is not an autooctoploid.
    4) Three F1-hybrids with 2n=5x=45 between diploid Ch. boreale and Ch. ornatum (Yakushima Isl. strain) were obtained by ovary culture. The following meiotic configurations were frequently observed; 1 IV+19 II+3 I, 5 III+12 II+6 I, 2 III+17 II+5 I, 21 II+3 I and 20 II+5 I. The chromosomes derived from Ch. ornatum (Yakushima Isl. strain) paired homoeololgously.
    5) The genetic control system for the suppression of multivalent formation in octoploid, its polyhaploid and pentaploid F1-hybrid must be the restriction of pairing initiation at one of two sites per chromosome. This restriction seems to be under the polygenic control which leads to the super-suppression in accompany with the increase of gene dosage. This system tends to act in a relatively more harmonious fasion in the even-numberd polyploid than in the odds.
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  • III. Decaploid Ch. crassum Kitamura
    Kuniaki Watanabe
    1981 Volume 46 Issue 3 Pages 515-530
    Published: September 25, 1981
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1) In Ch. crassum with 2n=10x-1=89, 44 II+1 I was the main meiotic configuration and 1 IV+42 II+1 I and 43 II+3 I were rarely observed. Eighty-nine chromosomes, at mitotic metaphase, varied in length from 5.4μm to 2.5μm and in arm ratio from 1.0 to 5.8. Five satellite chromosomes, two medium-sized and six small chromosomes with extreme subterminal centromeres were well distinguishable. Karyomorphologically this species is not an auto-decaploid.
    2) Three F1hybrids with 2n=6x=54 between diploid Ch. boreale and Ch. crassum were obtained by ovary culture. The following meiotic configurations were frequently observed; 2 IV+23 II, 1 IV+25 II, 1 III+25 II+1 I, 27 II and 26 II+ 2 I. The chromosomes derived from Ch. crassum paired both homoeologously and homologously with the Ch. boreale chromosomes.
    3) F1-hybrids with 2n=6x=54 between Ch. boreale and Ch. crassum gave rise to tetraploid B1-hybrids by means of ovary culture after being backcrossed with the diploid Ch. boreale. In B1-hybrids with 2n=4x=36 the following meiotic configurations were frequently observed; 3 IV+12 II, 2 IV+14 II, 1 IV+16 II, 18 II and 17 II+2 I. The maximum number of quadrivalents per PMC varied from five to two among B1-hybrids. The data of quadrivalent frequencies conform to the Poisson distribution. Further homoeologous chromosome pairing was observed in this generation.
    4) The diploid-like meiosis in Ch. crassum, its hexaploid F1-hybrids and tetraploid B1-hybrids must be ensured by the following genetic system although all of the constituent genomes of these polyploids are sufficiently homologous to be able to pair each other; 1) chromosome pairing is initiated at two sites, A and B (the zygomeres localize in two loci per chromosome). 2) at either site pairing is always two-by-two, with the pairing initiated at the A site being independent of that initiated at the B site. 3) the initiation of pairing at the A site always precedes to that at the B site. 4) the initiation of pairing at the B site is usually suppressed by multiple-or polygenic control. The magnitude of release from the suppression of initiation of pairing at the B site depends on the reduction of suppressive gene dosage and seems to be equal, not differential, at each B site.
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  • II. The determining factor of the distribution of centromeric regions in the nucleus
    Noriyuki Tanaka
    1981 Volume 46 Issue 3 Pages 531-544
    Published: September 25, 1981
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1. The distribution of the centromeric regions in prophase and telophase nuclei was investigated in the root tip cells of 33 angiospermous plants.
    2. The centromeric regions were located close to the nuclear envelope. The relative extent of the distributional range of the centromeric regions in the nucleus was nearly constant for each species, but often differed among the species examined.
    3. Three types (type 1, 2, and 3) were distinguished as to the relative extent of the distributional range of the centromeric regions in the nucleus. Of 33 species examined, 16 species belonged to the type 1 which was defined to have the smallest range, 8 species belonged to type 2, and 9 species belonged to the type 3 which was defined to have the broadest range.
    4. It was suggested that the configurative characteristic of the anaphasic chromosomal group is important as a determining factor of the extent of the distributional range of the centromeric regions in the nucleus. As a value denoting this characteristic, A/C-value (see the text) was calculated for each species. The species with relatively high A/C-value tended to show a small distributional range, while the species with relatively low A/C-value tended to show a broad range. The species having holocentric chromosomes showed the broad distribution of chromosomes inside the nuclear envelope.
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  • III. Haplopappus gracilis (2n=4) and Crepis capillaris (2n=6)
    Noriyuki Tanaka
    1981 Volume 46 Issue 3 Pages 545-559
    Published: September 25, 1981
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1. Observations of the chromosomal arrangement and behavior were made in the meristematic cells of the root tips of H. gracilis (2n=4) and C. capillaris (2n=6).
    2. In the prophase and telophase nuclei, the centromeric regions of chromosomes were localized in a relatively small area of the nuclear envelope. During prometaphase, the centromeric regions migrated toward the equatorial plane, keeping their arrangement at prophase. During anaphase, the relative arrangement of the chromosomes was the same between the two separating chromosomal groups. These observations suggested that the relative arrangement of chromosomes is likely to be retained through the mitotic cycle.
    3. In the two nuclei of two adjacent cells, or of the binucleate cells induced by caffeine, the occurrence of the same relative chromosomal arrangement pattern was significantly high. This fact also seems to support the suggestion mentioned above.
    4. In H. gracilis, non-random manner of chromosome disposition was revealed from a statistical approach. While in Crepis, a pair of nucleolar chromosomes deviated from random disposition and showed some tendency of lying side by side. Derivation of this non-random disposition was discussed briefly, and it was conjectured from all observations that the individual chromosomes are essentially independent in occupying their spatial positions.
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  • B. T. Backus
    1981 Volume 46 Issue 3 Pages 561-566
    Published: September 25, 1981
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Specimens of Paludicella articulata collected in the vicinity of Washington, D. C. had 2n=22, with a usual karyotype consisting of a relatively large submetacentric set, 4 metacentrics, and 6 subtelocentrics. A few specimens showed a subtelocentric replacing one member of a metacentric set. Hyperploid cells, with from 26 to 35 chromosomes, were found in some morphologically normal colonies. In one instance, 12 hyperploid spreads and a few normal ones were obtained from a terminal bud. This is the first report of hyperploidy in the Bryozoa.
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  • L. Janardhana Reddy
    1981 Volume 46 Issue 3 Pages 567-577
    Published: September 25, 1981
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    On the basis of relative length, arm ratio, chromomere pattern and nucleolar association all the eleven pachytene chromosomes of A. sericea were identified. The pachytene complement consists of 2 median, 8 submedian and 1 subterminal chromosomes. On the basis of comparison of parental pachytene chromosomes, 7 are common to A. sericea and Cajanus. Complete synapsis in majority of the microsporocytes of Cajanus×A. sericea hybrid indicates a high degree of homology. In the hybrid, out of eleven bivalents, eight bivalents, including two exhibiting heteromorphism were identified. Occasionally two translocations and a duplication loop were observed in a few cells. On the basis of various evidences, it is concluded that A. sericea has a lesser degree of affinity to Cajanus than A. lineata.
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  • L. Janardhana Reddy
    1981 Volume 46 Issue 3 Pages 579-589
    Published: September 25, 1981
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    All the eleven pachytene chromosomes of A. scarabaeoides were identified on the basis of their relative length, arm ratio, chromomere pattern and nucleolar association. The pachytene complement of A. scarabaeoides consists of one median, 9 submedian and one subterminal chromosomes. On the basis of direct comparison of parental pachytene chromosomes, 7 chromosomes are common to A. scarabaeoides and C. cajan. In 8 bivalents of the hybrid the homoeologues participating in pairing were identified. Out of these 8, one bivalent showed non-homologous association and 4 were found to be heteromorphic. Two translocations and an interstitial duplication were noticed in a few microsporocytes. On the basis of the common chromosomes involved in translocations and those exhibiting heteromorphism in the 2 hybrids, C. cajan×A. sericea and C. cajan×A. scarabaeoides but not in the C. cajan×A. lineata hybrid it is concluded that A. sericea and A. scarabaeoides are closer to each other than either of them to A. lineata.
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  • B. C. Joshi, Dalmir Singh, R. N. Sawhney
    1981 Volume 46 Issue 3 Pages 591-597
    Published: September 25, 1981
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Monosomic lines (2n=41) of wheat were crossed with Triticum macha and data were recorded on the monosomic F1's on, a) mean pairing per chromosome, b) multivalent associations per cell and c) chiasma formation per bivalent. Comparison of the data with the control cross (wheat disome × T. macha) revealed that: 1) suppressors for pairing of homoeologous chromosomes are located on chromosomes 4B and 1D of T. macha, the pairing per chromosome in the F1monosomic hybrids of these lines being significantly lower than that of control, 2) chromosomes 6A, 3B, 4B and 1D of T. macha possess promotors for homoeologous chromosome pairing. The monosomic F1hybrids of these lines exhibited significantly higher multivalent associations per cell, as compared with the control, and 3) genes present on chromosomes 4A, 1B, 5B and 1D of T. macha suppress chiasma formation.
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  • XI. Various causes which prevent an elucidation of mitosis
    Bungo Wada
    1981 Volume 46 Issue 3 Pages 599-621
    Published: September 25, 1981
    Released: March 19, 2009
    JOURNAL FREE ACCESS
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  • Rehab K. Al-Kelidar, A. J. Richards
    1981 Volume 46 Issue 3 Pages 623-633
    Published: September 25, 1981
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Delphinium has about 250 species circumboreally. Of these, 22 are examined cytologically here; 8 are diploid (2n=16) and 14 tetraploid (2n=32). Most accessions from Botanic Gardens were wrongly named. Over 20 types of chromosome were identified; karyological relationships were calculated and show a rough correspondence with taxonomic groupings. Chromosomes with a median centromere had an average length three times that of telocentrics. In diploids, there is a relationship between mean chromosome length and the amount of DNA in the nucleus, suggesting that DNA-rich areas are lost in chromosome re-organisation. It is suggested that species with smaller mean chromosome length can be considered to be karyologically derivative. Karyological trends are seen in both diploids and tetraploids, Consolida regalis being derivative with respect to C. ambigua, and Delphinium section Delphinastrum being derivative with respect to sections Staphisagnia and Diedropetalia. DNA synthesis appears to be faster in nuclei with less DNA, contrary to expectations.
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  • D. Kumar, P. Paria, S. L. Basak
    1981 Volume 46 Issue 3 Pages 643-647
    Published: September 25, 1981
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Studies on chiasma frequency, internuclear variation of chiasmata and premeiotic spindle error producing heteroploid PMC's, described as meiotic lability, in 8×8 diallel crosses of jute (Corchorus olitorius L.) have elucidated that dominant gene action plays a major role in controlling these characters. Heterosis was present for chiasma frequency and internuclear variation of chiasmata and was absent for meiotic lability. Low value of chiasma frequency was dominant over their higher value and higher value of internuclear variation of chiasmata was dominant over their lower value. Imbalance in heterozygotes was found in meiotic lability.
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  • II. Behavior of the chromosomes during the generative nuclear division in Allium fistulosum
    Akio Kamizyô, Nobunori Tanaka
    1981 Volume 46 Issue 3 Pages 649-659
    Published: September 25, 1981
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Behavior of the generative nuclear chromosomes in the cultured pollen tube in Allium fistulosum have been studied. The mitotic phases from mid-prophase to late-prophase and that from metaphase to telophase were observed in the 2 and the 4 hr cultures, respectively. By means of C-banding technique, it became clear that the constitutive nuclear topograph has been held invariable through telophase of the primary microspore division in a pollen grain to prophase of the secondary generative nuclear division in a pollen tube. Free spindle-formed germ cell in the pollen tube cytoplasm changes itself into an oval-like form before going into the secondary generative nuclear division. It seems very reasonable that thus formed mitotic germ cell could have a wholeround directional mitotic axis in the pollen tube. Usually mitotic axis seems to have a right angle orientation against the pollen tube membrane. But when the spindle body prepares to extend, the mitotic axis may inevitably rotates to get the most stable orientation in the pollen tube. The vegetative nucleus (=the pollen tube nucleus) usually wanders near-by the germ cell, but sometimes, it changes its form into a filamentous, extremely extended form as seen in Fig. 19. The reason why such transformation does occur remained to be studied.
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  • S. P. Vij, J. D. Chaudhary
    1981 Volume 46 Issue 3 Pages 661-669
    Published: September 25, 1981
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Cytological studies were made in Cenchrus biflorus (n=16, 17, 18), C. ciliaris (n=18, 18+0-2B's) and C. setigerus (n=17). Different cytotypes in the first two species overlapped in their morphological traits. Predominant occurrence of the cytotypes n=17 (C. biflorus) and n=18 (C. ciliaris) suggests their stability in the area under study. A heavy natural selection on the other hand explains the rarity of new chromosome types n=16, 18 in the former and n=18+0-2B's in the later species respectively.
    Dibasic nature of Cenchrus with x=9 and 17 is evident and majority of its speciation seems to have centered around the later number. Complete bivalentization and 18 duplets point to an amphiploid nature of C. biflorus, whereas, variable number of bivalents and/or quadrivalents together with the categorization of somatic chromosomes as 9 quadruplets (C. ciliaris) and 8 quadruplets and one pair (C. setigerus) indicates chromosomal homologies.
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  • W. A. Bowker, G. M. Halloran
    1981 Volume 46 Issue 3 Pages 671-674
    Published: September 25, 1981
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    A method has been developed for examining mitosis in the leaf meristem of graminaceous plants using perennial ryegrass (Lolium perenne L.), annual ryegrass (Lolium rigidum Gaud.), hexaploid wheat (Triticum aestivum L. em Thell.), oats (Avena sativa L.) and barley (Hordeum vulgare L.). The method consistently gives a high frequency of mitotic stages and appears to have advantages over root-tip methods for examining somatic chromosomes in certain genetic and breeding studies.
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  • S. S. Cheng, M. J. Bassett
    1981 Volume 46 Issue 3 Pages 675-684
    Published: September 25, 1981
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Meiotic chromosomes of common beans (Phaseolus vulgaris) were stained with 45% iron propionic carmine to study changes in morphology during the condensation process at the diplotene stage. Chromosome morphology was studied with a stereo dissecting microscope at 20×using contact sheet prints of photomicrographs taken with a phase contrast system at 1000×. The banding patterns of each chromosome are unique and can be used to identify that chromosome at diplotene. The relative chromosome length can only be used to separate the chromosomes into long and short classes because of the differential condensation rates of chromatic and achromatic chromosome segments. A set of diplotene chromosome diagrams is provided.
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