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R. S. Sangwan, H. Camefort
1984 Volume 49 Issue 3 Pages
473-487
Published: September 25, 1984
Released on J-STAGE: March 19, 2009
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Effects of low temperature (3°C for 48h) on microspores (n) and on parenchymatous somatic tissue (2n) of anthers of
D. metel have been studied. The general pattern of ultrastructural changes in microspores and parenchymatous cells differ despite some similarity in the initial sites of low temperature action on vacuolization of the cytoplasm. The cold stress modifications are more marked in somatic tissues than in the microspores. The general cold-stress responses are: vacuolization and loss of cytoplasmic structure, disorganisation of organelles, darkening of cell wall and apparent loss of turgor pressure. The starch grains in the plastids begin to disappear or to reduce in size when the chilling stress is applied. Periodic structures appear in the vacuole and the first intine of the androgenic microspores. Apparent modifications are also observed in plastids, mitochondria, nuclei and plasma membrane. The significance of these structural changes in relation to androgenesis is discussed.
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Constantin Craciun, Dorina Cachia-Cosma, Viorel Saran
1984 Volume 49 Issue 3 Pages
489-496
Published: September 25, 1984
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Electron microscopic investigations on the cells obtained from tissue cultures of carnation (
Dianthus caryophyllus var. Linda), have demonstrated the presence of two types of particular formations in the nucleus: a) electrondense loose bodies, composed of fibrillary structures; b) unelectrondense spherical-oval areas, with a slightly expressed structure. The possible connection of these structures with the nucleolus and nucleus-membrane functions, as well as their role in the rRNA synthesis and in the transfer processes through nucleus and cytoplasm, are discussed.
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III. Haemanthus multiflorus Martyn (Amaryllidaceae)
O. C. Nwankiti
1984 Volume 49 Issue 3 Pages
497-500
Published: September 25, 1984
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Shubhada R. Thengane, V. R. Dnyansagar
1984 Volume 49 Issue 3 Pages
501-511
Published: September 25, 1984
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Cytogenetical investigations were undertaken in
Carum copticum, an Umbellifer of medicinal importance for its commercial source of essential oil containing thymol. The present paper deals with cytological studies with special reference to meiotic analysis. Mitosis is normal with chromosome number 2n=18. The karyotype is symmetrical indicating that the plant belongs to the subline of
Pastinaca-Foeniculum-Selenium in the evolution of Umbelliferae. Meiotic analysis reveals that meiosis is normal. The intranuclear variance is more than internuclear variance indicating in general a negative correlations.
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Juan C. Vilardi
1984 Volume 49 Issue 3 Pages
513-528
Published: September 25, 1984
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Karyotype and meiotic behaviour were analyzed in two Argentine populations of
S. longicornis (G. Tos). It was found that the basic karyotype in this species is composed by 23 telocentric chromosomes in males (22 autosomes+X) with a sexual mechanism XO _??__??_/XX _??__??_. Chromosome variations involving a centric fusion, a pericentric inversion, elastic constrictions and a supernumerary segment were detected. The study of chiasma frequency and movement allowed to establish that: 1) there is a continuous chimasma movement and terminalization from diplotene to MI; 2) the differences between populations are non significant though there is a high within population variability; 3) the rearrangements observed have no obvious influence on chiasma conditions. C-banded meiotic karyogram at diplotene, made with Ba (OH)
2 and 2×SSC, is described. It demonstrates centromeric, interstitial and telomeric bands in meiotic autosomes. The X and megameric pair were totally heterochromatic.
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H. J. Wichers, J. ten Kate, C. H. C. M. Buys, H. J. Huizing
1984 Volume 49 Issue 3 Pages
529-535
Published: September 25, 1984
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A simple procedure is described for the isolation of protoplasts from plant cells using a high concentration of magnesium sulfate as an osmotic stabilizer. This new procedure was developed with callus cells of
Symphytum officinale as a starting material, but was also successfully applied to other tissues and other plants. The floating protoplast fraction obtained had a purity of more than 90% and was highly enriched in nucleated protoplasts (about 80%). Microdensitometry of Feulgenstained fixed protoplasts from callus cells of
Symphytum officinale revealed two ploidy levels (diploid and tetraploid), in contrast to protoplasts from leaf material that appeared to be diploid only.
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Edmundo José de Lucca
1984 Volume 49 Issue 3 Pages
537-545
Published: September 25, 1984
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Karyotypes were compared in 5 species of
Aratinga (Psittaciformes). The macrochromosomes of each species were analysed by the conventional Giemsa staining, with cytobiometry, and G- and C-banding. All the species showed 2n=70 chromosomes. These karyotypic data are compared to those in the literature on nine other parrot species. The reduced chromosome number in
Aratinga was attributed to the fusion of microchromosomes into macrochromosomes.
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M. S. Haque
1984 Volume 49 Issue 3 Pages
547-550
Published: September 25, 1984
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Somatic chromosome studies in 4 species of
Eucalyptus viz.,
E. torelliana F. Muell.,
E. citriodora Hook.,
E. camaldulensis Dehn.,
E. tereticornis Sm. were carried out with a view to determine the similarity or dissimilarity if any, in their chromosome morphology. All the species had 2n=22 very small chromosomes. No significant differences in the chromosome complement of any species were found except in the pair with secondary constriction which was larger. All the 4 species had more or less symmetrical karyotype.
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K. J. Madhusoodanan, O. P. Arora
1984 Volume 49 Issue 3 Pages
551-556
Published: September 25, 1984
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Various chromosomal types were obtained from a hypotetraploid (2n=35) of
M. chamomilla L, isolated from the progeny of an induced autotetraploid plant. Karyological analysis reveals preferential transmission of small subterminal chromosomes as these are never eliminated in any of the aneuploids obtained. The absence of 3 median chromosomes from the fourth quadriplex of the plant with 2n=33 seems to boost multivalent frequency and also accentuates desynapsis caused by high temperature.
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A. Mujeeb-Kazi, R. Rodriguez
1984 Volume 49 Issue 3 Pages
557-565
Published: September 25, 1984
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Three
Hordeum vulgare×
Triticum aestivum hybrids are described. The phenotypic expression of the hybrids was similar to
T. aestivum. The overall mean chromosome association in the hybrids was 24.3
I+1.33
II (rods), +0.38
II(rings)+0.15
III+0.03
IV+0.003
VI with a 2.57 mean chiasma frequency per cell. Early pollinations of the hybrids, before stigma receptivity was evident, with respective
T. aestivum cultivars, followed eight and 32 hours later by gibberellic acid (75 ppm aqueous) treatment into the floret cups yielded first backcross (BC
1) seed set. The plants that resulted after embryo culture ranged in chromosome numbers from 27 to 50. Similar early pollinations of the BC
1 plants with
T, aestivum, coupled with two post-pollination applications of gibberellic acid after eight and 32 hours produced over 100 BC
2 seeds. All BC
2 plants remained self-sterile.
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K. G. Raja Rao, Y. Lydia Prasad
1984 Volume 49 Issue 3 Pages
567-572
Published: September 25, 1984
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Pachytene chromosome morphology of the haploid complement of
P. lanceifolia Nees (n=12) was studied. They are characterised by the presence of heterochromatic and euchromatic segments. An idiogram was constructed based on chro-mosome length, lengths of heterochromatic and euchromatic segments and arm ratios. Chromosome 11 has the nucleolus organiser in the totally heterochromatic short arm.
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Rossitsa Belcheva, Vulko Bisserkov
1984 Volume 49 Issue 3 Pages
573-581
Published: September 25, 1984
Released on J-STAGE: March 19, 2009
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The black rat (
Rattus rattus L.) from Bulgaria belongs to the Oceanian-type (n=38). Chromosomal analyses show that a polymorphism occurs in chromosomes nos. 9, 10 and 13 due to pericentric inversions. A polymorphism concerning size difference of centromeric heterochromatin (C-band) in some of the chromosomes is observed. The analyses of G-band patterns demonstrate that there are no differences between our material and the other black rats with 38 chromosomes. The NORs of the black rat (
R. rattus) are found in telomeric regions of the short arms of chromosome pairs 3, 8, 13 and in telomeric region of the long arm of chromosome pair no. 10. A polymorphism due to supernumerary chromosomes is detected. The supernumeraries are metacentric and acrocentric. They show centromeric C-band after C-band staining.
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Subtribes: Pogoniinae, Thuniinae, Bletiinae, Coelogyninae, Epidendrinae
P. N. Mehra, S. K. Kashyap
1984 Volume 49 Issue 3 Pages
583-595
Published: September 25, 1984
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This paper deals with the cytology of 14 species comprising 8 genera of Epidendreae. The genus
Pachystoma (
P. senile: n=20) has been investigated for the first time. B-chromosomes are reported in
Calanthe puberula (2n=40+1B) and
Pholidota articulata (n=20-0-3B). An aneuploid race of
Eria confusa (n=18) is discovered. The chromosomes in Pogoniinae, Thuniinae and Bletiinae are larger in size compared to htose of Coelogyninae and Epidendrinae which are relatively much smaller.
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Subtribes: Liparidinae, Oberoniinae, Dendrobiinae
P. N. Mehra, S. K. Kashyap
1984 Volume 49 Issue 3 Pages
597-611
Published: September 25, 1984
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Cytological studies were carried out in 24 species belonging to 6 genera of Liparidinae, Oberoniinae and Dendrobiinae. Five species,
Liparis cordifolia (n=10),
L. deexa (n=21),
Oberonia auriculata (n=15),
Bulbophyllum raui (2n=40) and
Cirrhopetalum refractum (n=19) are investigated for the first time. New chromosome numbers were added to five species. The genus
Oberonia shows a consistent basic chromosome number of n=15.
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Subtribes: Crytopodiinae, Cymbidiinae, Sarcanthinae
P. N. Mehra, S. K. Kashyap
1984 Volume 49 Issue 3 Pages
613-627
Published: September 25, 1984
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Cytological investigations were carried out in 16 species included in 12 genera of Epidendreae. One species of the genus
Oreorchis (
O. indica: 2n=42) is investigated for the first time. New chromosomal reaces were discovered in
Aerides odoratum (n=18),
Doritis taenialis (n=19, 2n=57) and
Vanda cristata (2n=38, 2n=76). It is concluded that the comprehensive tribe Epidendreae (sense Dressler and Dodson) should really be split into 3 distinct tribes Epidendreae, Malaxideae and Vandeae as originally proposed by Lindley. In each of these alliances there is gradual reduction in size of chromosomes from the more primitive to the advanced ones with the adoption of epiphytic mode of life from the original terrestrial base.
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R. C. Gupta, B. S. Gill
1984 Volume 49 Issue 3 Pages
629-633
Published: September 25, 1984
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Autotriploid of
Chrysanthemum coronarium, a winter ornamental with considerable structural heterozygosity, was obtained through open pollination of induced autotetraploid. The triploid with radiate yellow capitula was luxuriant with large sized capitula which are fewer in number. Besides trivalents, it has multiple associations constituted as a consequence of structural heterozygosity for reciprocal translocations. In spite of large chromosome size and high chiasma frequency in the diploid, only 55% chromosomes are involved in multivalents. Of the trivalents, ‘chain’ type is the most common. In spite of 56% pollen fertility, the triploid completely lacks achene formation. Maintenance of triploid was not possible for the species lacks vegetative multiplication.
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K. Jayalakshmi, J. V. Pantulu
1984 Volume 49 Issue 3 Pages
635-643
Published: September 25, 1984
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The effects of B-chromosomes on A-chromosome chiasma frequency and distribution were studied in
Pennisetum typhoides (2n=14). Since B-containing plants of this species are mosaics, showing variation in B-numbers, both within and between tissues, the analyses have been based on pooled data derived from cells with the same B-phenotype but from different individuals. The results obtained on the effects of the three types of Bs viz., standard, deficient and iso Bs largely asgreed with those of the earlier reports. The earlier findings that there is threshold value for iso Bs and the effect of one iso B is same as that of two, three and four is presumed to be due to the presence of an upper limit for chiasma frequency per cell beyond which there cannot be further increase. It is suggested that there are a unmber of sites on the long arm of the long arm of the B-chromosomes which may be responsible for their effect on A-chiasma frequency. The differential effects of the three types of Bs are then assumed to be due to the relative number of such sites present with iso Bs having more sites than standards and deficients fewer than standards.
The effect of B-chromosomes on the distribution of A-chiasmata-between PMCs within a plant, between bivalents within PMCs and within bivalents between the two arms-was also studied. The cell variance of chiasma frequency increased within individuals carrying standard, deficient or iso Bs. The over all pattern regarding chiasma variance between bivalents within PMCs was that standard Bs and deficient Bs did not have any effect, whereas iso Bs increased the chiasma variance and the extent of this was proportional to their number. The chiasma distribution in individual bivalent arms was analysed by assessing the proportion of non-distal chiasmata and also the proportion of rod bivalents with two chiasmata in one arm. Standard Bs and deficient Bs decreased, while iso Bs increased, the proportion of non-distal chiasmata per cell. The correlation coefficients obtained, however, were not significant. Non-distal sites also become equally active in the presence of all three categories of B-chromosomes.
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Q. N. Ahmad, E. J. Britten, D. E. Byth
1984 Volume 49 Issue 3 Pages
645-658
Published: September 25, 1984
Released on J-STAGE: March 19, 2009
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Glycine sofa, a wild species of Eastern Asia, is the closest relative of the soybean,
Glycine max. Its chromosome number is the same as that of the soybean (2n=40). The chromosomes are small and difficult to manipulate. The quantitative methods used in studying
G. max were employed to determine the genomic structure of
G. sofa. The investigations included the matching of chromosomes to establish homoeologous pairs, the identification of those chromosomes which could be distinguished morphologically, and classifying numerically the chromosomes which could not be identified individually. An idiogram was prepared of the identifiable chromosomes and a standard karyotype of the whole genome is proposed. The karyotype consisted of 12 metacentric and 8 submetacentric chromosomes.
The karyotypes of
G. max and of
G. sofa were then compared. The total length of the chromosome complement of
G. sofa was found to be about 6-7 percent smaller than that of
G. max. When the chromosomes of each species were matched with those of the other to determine homoeologous pairs, it was found that 16 of the 20 in the two genomes were morphologically similar.
The four chromosomes which did not correspond morphologically were then examined in greater detail. On the basis of lengths and arm ratios, these differences were considered to have arisen from evolutionary changes in the chromosomes of a common ancestor to give rise to those of the present two species. Of the two more likely methods of change, it was considered that deletions in the karyotype of the ancestor to bring about the
G. sofa chromosome configuration was more probable than duplication to develop the
G. max karyotype. Details of the changes which may have occurred were given for each chromosome.
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Ashok Kumar Giri, Om Pal Singh, Ratna Sanyal, Archana Sharma, Geeta Ta ...
1984 Volume 49 Issue 3 Pages
659-665
Published: September 25, 1984
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A total of 18 metallic salts belonging to seven groups of the periodic table have been applied in sublethal chronic doses on plant and animal cells
in vivo for their comparative action on cell division.
Usually within the members of a particular group inhibition of mitosis and induction of chromosomal abnormalities increased with increasing molecular weight. There was a general direct proportionality with dosage applied and the cytotoxic action, though occasionally there was an increase in very low doses. These effects were more general in nature and could not be specifically attributed to any particular cell component. The amounts of total DNA and RNA showed a general decrease with increased dosage and period of treatment.
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Hitoshi Suzuki, Tosihide H. Yosida
1984 Volume 49 Issue 3 Pages
667-672
Published: September 25, 1984
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Frequencies and distribution of chromatid breaks (CBs) and sister chromatid exchanges (SCEs) induced by hydroxyurea (HU) were examined in Chinese hamster D-6 and lung primary cultured cells. About 30 to 50% of regions in CBs occurring by HU associated with those of the SCEs. Association of CBs and SCEs was examined by other chemicals such as BrdU, FdU, dA, dG, and Dt, which induced both SCEs and CBs. The association rate was obtained at about 20 to 50% by them. A highly associating region (about 80%) was found on X chromosome of D-6 cells, but it was not found in the lung cultured cells. Such association of SCEs and CBs was discussed in relation to the Revell's hypothesis.
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Tomosaburo Yabuno
1984 Volume 49 Issue 3 Pages
673-678
Published: September 25, 1984
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Echinochloa oryzoides (Ard.) Fritsch is distributed in Australia and southern Europe to eastern Asia. The habitat is confined to the rice fields, and has the erect plant architecture.
E. oryzoides can be recognized as a lowland rice mimic. The chromosome number is n=27. Artificial hybrids of
E. oryzoides with the two varieties of
E. crus-galli (n=27) were easily produced. It was elucidated that
E. oryzoides is closely related to
E. crus-galli, having the same genomic constitution in common. Cytologically and morphologically
E. oryzoides might be. relegated to a variety of
E. crus-galli.
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