CYTOLOGIA
Online ISSN : 1348-7019
Print ISSN : 0011-4545
Volume 50 , Issue 4
Showing 1-34 articles out of 34 articles from the selected issue
  • C. Ramachandran, V. S. Seshadri, R. A. Pai
    1985 Volume 50 Issue 4 Pages 631-641
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Karyological studies were conducted in dessert and non-dessert forms of C. melo collected from different parts of the World. No major variation in somatic chromosome number was observed except for the occurrence of B-chromosomes and polysomatic cells in low frequencies. The variation noticed in individual chromosome length, total chromatin length, centromere position, satellite number and position, chiasma frequency, etc., can be correlated per se with polymorphism in muskmelon. The study of chiasma frequency has revealed the role of sex form on crossing over; but the findings do not corroborate with Correns hypothesis of evolution of sex. The present investigation supports the domestication of dessert melons in India through Mughal invasion and also shows evidence for the existence of nondessert forms of C. melo in South India prior to Mughal invasion.
    Download PDF (2904K)
  • Maria del Carmen Molina
    1985 Volume 50 Issue 4 Pages 643-648
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    It had been obtained a tetraploid hybrid (2n=40), crossing Z. diploperennis (2n=20) with Z. perennis (2n=40) by non disjunction of the gametes of Z. diploperennis.
    The cytological study indicated that there were no univalents and trivalents. Most of the chromosomes paired as bivalents and tetravalents preferently openring. The average of the counts in 214 cells in diakinesis was: 0.24I, 11.29II, 0.06III and 4.20IV. The average of chiasmata was 31.42 and at pachynema some translocations and inversions were observed.
    In anaphase in the 78% of the cells the same number of chromosomes migrated to each pole and in the left 22% different number of chromosomes migrated towards each pole or remained as lagging chromosomes. Only exceptionally chromatid bridges were observed.
    The fertility of the pollen is 56% with 80% of fertile seed being the progeny fertile and vigorous.
    Download PDF (1955K)
  • Animesh K. Datta, Amal K. Biswas
    1985 Volume 50 Issue 4 Pages 649-654
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    A phenotypically aberrant and sterile plant was identified in the selfed progeny of a EMS- induced M2 mutant (lax branching) of Nigella sativa L. (black cummin), showing cytomixis and aneuploid variations. The aberrant plant revealed aneuploid and polyploid variations in the meiotic cells with remarkably high sterility of pollen and extreme reduction of pollen size. Such meiotic variations occurring within the microspore mother cell of the same microsporophyll have been referred to as “chromosomal mosaic”. It is most likely that the aberrant plant has arisen due to some cytological anomalies as a consequence of cytomixis, and the meiotic instability manifested by the plant leading to chromosomal mosaic might have occurred due to premeiotic mitotic disturbances.
    Download PDF (4681K)
  • A. B. Sapre, Suniti S. Barve, Dayarani S. Deshpande
    1985 Volume 50 Issue 4 Pages 655-661
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Download PDF (1893K)
  • Ma. del Carmen Maldonado-Monroy, Manuel Uribe-Alcocer, Julio Arreguin- ...
    1985 Volume 50 Issue 4 Pages 663-669
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The cytogenetic study of Dormitator maculatus and Gobiomorus dormitor, fish species belonging to the family Gobiidae, was made. The studied specimens were collected in the Papaloapan river mouth and Alvarado Lagoon in the coast of the Gulf of Mexico. The methodology employed to obtain the karyotype is described. The diploid number found for D. maculatus is 46 and its fundamental number is 90. G. dormitor has 48 chromosomes and its fundamental number is 54. No evidence of heterochromosomes was found in either species. The numerous differences between their karyotypes do not denote close phylogenetic relationship between them.
    Download PDF (354K)
  • Vijeshwar Verma, S. N. Sobti
    1985 Volume 50 Issue 4 Pages 671-682
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The B-chromosomes were detected in two species (C. martinii var. motia and C. jwarancusa) out of the 9 species of genus Cymbopogon investigated. The supernumerary chromosomes were found in both the root-tip meristematic cells as well as the PMCs. Investigations with respect to nature and behaviour of the accessary chromosomes were made in the two parental B-chromosomes carrying species, their F1 hybrids with other Cymbopogon species and in the F2 population raised from one of the partially fertile F1 hybrids. The above study clearly shows that the B-chromosomes have a direct effect on the total chromatin length and the chiasma frequency of A-chromosomes. However, no effect on the general morphology or chemical composition of the oil of the plants has been noticed in presence of the accessary chromosomes. The significance of the data on accessary chromosomes is discussed.
    Download PDF (4315K)
  • Tapas Kumar Dutta, Nripendra Kumar Bhattacharyya, Subir Sen
    1985 Volume 50 Issue 4 Pages 683-688
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Turn over of meiotic irregularities, pollen, capsule and seed sterility in M1 and M2 generations, derived from X-ray treated dry seeds of Linum usitatissimum L. (CV. B-67, Mukta and Neelum) were compared. Total percentage of meiotic abnormalities was highest in B-67 amongst the control population. But in comparison with respective controls, the turn over of meiotic irregularities was high in the M1 populations of Mukta and Neelum. The extent of irregularities in meiosis of M2 was less than that of M1 generation. The pollen sterility percentage in the two generations remained almost unchanged, while capsule and seed sterility were reduced in M2 generation.
    Download PDF (2217K)
  • V. K. Dimitriadis, C. D. Kastritsis
    1985 Volume 50 Issue 4 Pages 689-700
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The posterior midgut of Drosophila auraria larvae, and more specifically its anterior half, must be considered an important region for the digestion and the uptake of nutrients. The cells, and the region of the central lumen they define, are unique in that they give positive reaction for alkaline phosphatase; they also give the strongest histochemical reaction for leucine aminopeptidase. There are histochemical indications that the middle midgut, and especially its posterior region, can be a differentiated area of sugar storage.
    Download PDF (9797K)
  • A. Mujeeb-Kazi, J. L. Miranda
    1985 Volume 50 Issue 4 Pages 701-709
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    A somatic cytological technique is described as an aid to superior resolution of primary and secondary chromosome constrictions. Initially, intergeneric hybrids among some Triticeae can be readily identified by routine chromosome number counts, chromosome size or morphology, and satellite number. This includes those hybrids that involve parental combinations of similar polyploidy. Superior secondary constriction resolution can accurately enable detection of 1B/1R translocation in wheat varieties, advanced lines, or hybrid progenies derived from varieties that have the 1B/IR translocation. The results are discussed and photographically documented.
    Download PDF (5551K)
  • S. M. Handa, O. P. Mittal, Sunil Sehgal
    1985 Volume 50 Issue 4 Pages 711-724
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The male diploid number of chromosomes in 10 species of crickets of the superfamily Grylloidea vary from 11 to 29 with the XO sex mechanism in the male. The four species among these viz., Laxoblemmus deteerus, L. animao, Turanogryllus jammuensis and Stephoblemmus humbertiellus with 2n varying from 11-21 are recorded cytologically for the first time. The cytological reinvestigations on Gryllus bimaculatus, G. melanocephalus, Gryllodes sigillatus, Pleronemobius fascipes and Trigonidium cicindeloides form Chandigarh and its neighbouring areas have revealed the same findings like those of the earlier workers. In Gryllus confirmatus, however, been observed and discussed in this paper.
    Download PDF (10858K)
  • I. Karyotype analysis
    M. Z. Haque, M. B. E. Godward
    1985 Volume 50 Issue 4 Pages 725-738
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Karyotypes of three cultivars of Lactuca sativa (Webb's Wonderful, Lobjoit's Green Cos and Tom Thumb), Lactuca serriola collected from the field in the county of Essex, U.K. and a cultivar of Cichorium intybus (Witloof Chicory), were analysed in detail so that essential comparative information was available for use in later studies (Haque and Godward, Papers II, III and IV). Statistical data on chromosome lengths and centromere positions, together with the recognition of the nucleolar-organising chromosomes, enabled the nine chromosomes of the haploid sets to be recognised individually, and these were designated A, B, C, D, E, F, G, H and I, C and E being the nucleolar organising chromosomes, these being recognised in C. intybus for the first time. There were slight differences in chromosome lengths, the Lactuca sativa cultivars and L. serriola being distinguishable by their mean lengths, but only those of C. intybus were significantly smaller. Comparisons with the previously published data on Lactuca and Cichorium are made.
    Download PDF (5874K)
  • A. P. Gupta
    1985 Volume 50 Issue 4 Pages 739-746
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The identity of the so-called cresecent cell in the hemolymph of the cockroach, Gromphadorhina portentosa (Schaum) (Dictyoptera: Blaberidae) has been established. These hemocytes are indeed oenocytoids (OEs). The identity of these cells was con-firmed by observations in both the last instar nymphs and adults. The OEs appear as polymorphic anucleate cells. Each OE has a crescent-shaped inclusion body that generally fills the cell and gradually diminishes in size and density as the cell ages. The OEs vary from 16 to 28μm in length and 10 to 22.4μm in width. They generally constitute 2% of the total hemocyte counts in both nymphs and adults. The most peculiar features of the OEs in this cockroach are presence of a single crescent-shaped cytoplasmic body and gradual nuclear extrusion as these cells age. No nuclear extrusion was observed in any of the other five types of hemocytes found in this cockroach. The nuclear extrusion may occur at any point along the length of the cell, thus producing the various forms of anucleate cells. Histochemically, the inclusion body shows intense PAS-positivity and is Sudan Black B-negative. These cells may nlav an indirect role in the final stages of cuticle formation.
    Download PDF (6390K)
  • M. R. Jahnavi, U. R. Murty
    1985 Volume 50 Issue 4 Pages 747-758
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Chromosome morphology at pachytene was studied in two species; A. sp. (GKP 9990, Section. Erectoides) and A. villosulicarpa (Section. Extranervosae) and compared with the other sectional species. The genus Arachis appeared to be based on a basic karyotype of six differentiated chromosomes, three specialised chromosomes and one nucleolus organizer. The karyotypes of species belonging to sections Erectoides, Triseminale and Extranervosae appeared to be more primitive than sections Arachis and Rhizomatosae. The section Arachis appeared to be a natural group of cross-compatible species having the characteristic A chromosome with the exception of A. batizocoi. The pachytene chromosome morphology did not indicate a highly marked chromosomal differentiation between the A' and ‘B’ genomes assumed to be present in the cultivated groundnut. Specific differences have been thought to be brought about in the genus Arachis through minor structural repatterning and major genetic differentiation.
    Download PDF (4046K)
  • D. Subramanian
    1985 Volume 50 Issue 4 Pages 759-768
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Fifteen species of Ranunculaceae under eight genera have been studied, mostly collected from different regions of Ooty and Kodaikanal of Western Ghats. First record of chromosome numbers has been made in Ranunculus wallichianus, R. subpinnatus, R. reniformis, Clematis wightianus, Thalictrum dalzellii and T. saniculaeforme. On the basis of previous and present cytological data, there are n=7 and n=8 series in Ranunculus. All the species of Ranunculus studied here are higher polyploids and both aneuploidy and euploidy play important role in speciation.
    The previous karyological analyses of Anemone reveal two distinct series, one with n=8 and the other n=7. Both A. rivalaris and A. japonica have 2n=24 chromosomes and they should have derived from n=8 series. Both in the larger size and the same number of chromosomes, Naravelia zeylanica and Clematis wightianus are related together.
    The presence of fewer number of chromosomes and larger size of them indicates that Nigella damascena is a primitive species. All the three species of Thalictrum, namely T. javanicum, T. dalzellii and T. saniculaeforme possess 2n=16 chromosomes and perhaps, these taxa are diploids derived from n=8 series. The chromosomes are comparatively smaller in size in all these species.
    Aquilegia canadensis has 2n=32 chromosomes. This may be a polyploid and it should have originated from n=8 basic chromosome series.
    The population of Delphinium ajacis studied here is a diploid and that of D. belladonna a triploid and the basic chromosome number in Delphinium may be n=8. As far as this genus is concerned, higher polyploidy plays important role in specification.
    In general, the taxa of Ranunculaceae studied show a wide range of chromo-some numbers from 2n=12 to 2n=46. As most of the taxa studied show either 2n=16 or multiples of n=8, the basic number of the family may be n=8 and the other basic numbers should have derived from it. The species are highly variable and polyphyletic in nature, as evidenced by the wide range of chromosome numbers, chromosome sizes and total chromosome lengths of various species studied.
    Download PDF (1538K)
  • Akey C. F. Hung
    1985 Volume 50 Issue 4 Pages 769-772
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Karyotype and sex-determining system of Cylas formicarius from Louisiana were determined as 10AA+XX in females, and 10AA+XY in most males with a few individuals exhibited both XY and Xyyp karyotypes. The culture from Hawaii had only Xyp males, those from Guam, Tinian and Taiwan were mostly Xyp although some were Xyyp and a few had both the Xyyp and Xyp karyotypes in the same individual.
    Download PDF (2007K)
  • Eva Pip, Martin B. Levy
    1985 Volume 50 Issue 4 Pages 773-777
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    A rapid quantitative technique of nuclear track autoradiography is described which is reproducible and minimizes artifacts. The method is applied to human breast cancer cell cultures.
    Download PDF (2082K)
  • Localisation des ATPases et des nucléosides diphosphatases
    J. Serrigny, J. Dexheimer
    1985 Volume 50 Issue 4 Pages 779-788
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    En localisant, au niveau ultrastructural, les activités ATPasiques et NDPasiques, les auteurs se proposent d'étudier les rapports entre les deux partenaires de la symbiose pendant la phase biotrophique.
    Les activités ATPasiques du plasmalemme de l'hôte et du plasmalemme de l'endophyte montrent l'existence de transports actifs au niveau de l'interface. Les activités NDPasiques sont souvent observées sur les sites d'édification de matériel pariétal. Celles mises en évidence dans la matrice et sur le plasmalemme de l'hôte correspondent à la mise en place, par l'hôte de la couche d'isolement.
    Les activités NDPasiques du plasmalemme de l'endophyte pourraient être impliquées dans les transports entre la cellule-hôote et l'endophyte.
    La présence de ces activités enzymatiques dans l'interface confirme l'hypothèse de relations mutualistes pendant la phase biotrophique.

    A cytochemical study was made to examine the possibility that ATPase-activities and NDPase-activities may be involved in the transfer of nutrients between the Orchid and the fungus during the biotrophic phase of the symbiosis.
    The ATPase-activities of the fungal plasmalemma and the host plasmalemma show that the interface is a site of active transfer processes.
    The NDPase-activities are often associated with the building of cell wall.
    The activities of the matrix and the host plasmalemma are involved in the deposition of the encasement material laid down by the host.
    The activity of the endophyte plasmalemma may be involved in transport between the host cell and the symbiont.
    The presence of these enzymatic activities in the interface strengthen the hypothesis of a mutualistic symbiosis during the biotrophic phase.
    Download PDF (4346K)
  • Amal S. Shehab, Zakia, A. Abo-El-Khier
    1985 Volume 50 Issue 4 Pages 789-795
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    In this work, the effects of promethazine hydrochloride and chlorpheniramine maleate (antihistaminic drugs) on flower buds of Vicia faba and Allium cepa were studied.
    Two drugs gave high percentage of abnormalities in the two plants. The percentage of abnormalities was higher in the lst division after 24h recovery. Metaphases have the highest percentage of aberrations.
    Different types of abnormalities were met with stickiness, disturbed metaphases and ana-telophases, multipolarity, lagging chromosomes, bridges, breaks and fragments. Despiralization was noted in treated Vicia PMCs only. Multinucleate cells were also recorded.
    The two drugs were not effective pollen sterilizers.
    Download PDF (1988K)
  • V. Karyotype of two species of the genus Crinum and a related genus Hymenocallis
    O. C. Nwankiti
    1985 Volume 50 Issue 4 Pages 797-803
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Download PDF (2031K)
  • Dale W. Haskell, Owen M. Rogers
    1985 Volume 50 Issue 4 Pages 805-809
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    In binucleate pollen tubes the vegetative and generative cell nuclei are known to synthesize RNA. Nothing is known about RNA synthesis in trinucleate pollens. To determine whether RNA synthesis occurs in trinucleate pollen, Secale cereale pollen was studied. The vegetative and sperm cell nuclei of the in vitro grown pollen tubes were shown by autoradiography to incorporate [5-3H] uridine. This incorporation was interpreted as indicating the synthesis of RNA.
    Download PDF (1517K)
  • III. Cytology of Lal-farashi, Double-Kaseri, Hindwand-rakam, Kichhama-trail, Sabe-alif and Tursh-nawabi
    Ranbir Singh, B. A. Wafai, A. K. Koul
    1985 Volume 50 Issue 4 Pages 811-823
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Six triploid varieties of cultivated apple (Malus pumila Mill.) namely Lalfarashi, Double-kaseri, Hindwand-rakam, Kichhama trail, Sabe-alif and Turshnawabi having 2n=51 have been recovered from different orchards of Kashmir Valley. Although not as good as the diploids, they are far superior to the tetraploid variety Khatoon-trail in their fruit quality. Data on the chromosome pairing reveals intergenomal homology suggesting their auto- or segmental allotriploid nature. The six triploids exhibit varying degrees of intergenomal differentiation.
    Download PDF (4056K)
  • Alina E. Zinov'eva-Stahevitch, William F. Grant
    1985 Volume 50 Issue 4 Pages 825-836
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The genus Impatiens L. has undergone an extensive cytoevolution, resulting in a series of chromosome numbers ranging from n=3 to n=33. Microsporogenesis was examined in 26 taxa; 17 exhibited abnormalities, which included precocious separation, lagging chromosomes, and bridges. Multiple microspores, containing 1-9 supernumerary cells, were common. In seven species, selected pollen characters were examined. Pollen stainability range was to vary from 14-91%. Micro- and subnormal-sized pollen grains were common. Colpi number varied within species. The role of aberrant gametogenesis in generating new chromosome numbers in Impatiens is discussed; and evidence for the hybrid origin of some of the taxa presented.
    Download PDF (4648K)
  • Ganesh Prasad, D. K. Tripathi, S. N. Mathur
    1985 Volume 50 Issue 4 Pages 837-840
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    A double trisomic plant (2x+1+1=16) was obtained in the progeny of diethyl sulphate (0.3 per cent) treated barley. It was weak and dwarf and produced few tillers with short spikes. Pollen and ovule fertility were 27.0 and 2.5 per cent, respectively. MI configurations were 1III+1I+6III, 2III+5II and 2I+7II, the former being the most frequent. V- and rod-shaped trivalents were more prominent. Unequal separations and lagging of chromosomes were observed at AI.
    Download PDF (1804K)
  • II. Effects of seed-irradiation on chiasma frequency
    M. Z. Haque, M. B. E. Godward
    1985 Volume 50 Issue 4 Pages 841-853
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Seeds of Lactuca sativa (cultivars Lobjoits Green Cos, Tom Thumb) and Lactuca serriola collected from the field, were irradiated with 10 and 30 Kr of gamma radiation. These and control seeds were grown on, and the chiasma frequencies determined in the M1 plants. Chromosome types had been identified (Haque and Godward, Paper I) so that it was possible to determine chiasma frequency for each chromosome type. The relationship between chromosome length and chaisma frequency, dose and chiasma frequency, per bivalent and per nucleus, for each cultivar or species, was examined. There was reduction with dose of chiasma frequency in L. serriola, but increase with dose in the two clutivars of L. sativa. The results are discussed in relation to genic control of chiasma frequency, and genic control of sensitivity to radiation. Chiasma frequency was not determined in C. intybus.
    Download PDF (3994K)
  • Manju Lata, A. K. Sharma, S. S. Lal
    1985 Volume 50 Issue 4 Pages 855-857
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The present investigation have been carried out on the chromosomes of Haemonchus contortus by heat dry smear technique. The diploid chromosome number in the male of this species is 11 while in the female it is 12. The sex mechanism is of XO/XX type. Heteropycnotic sex chromatin body has been observed at the periphery of interphase nucleus of the male. Meiosis shows that the male and the female both are chiasmatic. Sex chromosome X is easily distinguishable in the male sex due to the differential staining behaviour and an univalent nature.
    Download PDF (2139K)
  • V. C. Mercykutty, H. Kumar
    1985 Volume 50 Issue 4 Pages 859-863
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Five tertiary trisomics, isolated in the progenies of interchange heterozygotes, were morphologically classified into four groups. They might be named as slender, succulent, enlarged internode and small-erect stipule, respectively. At MI, characteristic pentavalent configuration was accounted in 38.4% cells; the modal configuration was 1111+6II (50.0 %). At AI, 7-8 disjunction was about 66.7%. Pollen fertility ranged from 30 4 to 67.0 %, while seed yield was very poor, ranging from 0-4 seeds per plant.
    Download PDF (2179K)
  • M. R. Jahnavi, U. R. Murty
    1985 Volume 50 Issue 4 Pages 865-878
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Download PDF (781K)
  • Karyology of Anaecypris hispanica (Steindachner, 1866), Chondrostoma lemmingi (Steindachner, 1866), Rutilus arcasi (Steindachner, 1866) and R. macrolepidotus (Steindachner
    M. J. Collares-Pereira
    1985 Volume 50 Issue 4 Pages 879-890
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The karyotypes of four Iberian Cyprinids taxa are established by the analysis of the respective kidney metaphasic plates.
    Such endemisms of uniseriated pharyngeal teeth are characterized by presenting the most common diploid number found in the known Cyprinidae (2n=50). Their chromosomic complements are asymmetric and possess a reduced group of acrocentric pairs so, a high fundamental arm number. There is no evidence neither of heterochromosomes nor of intra and/or interindividual polymorphisms, with the exception of Ch. lemmingi in what concerns the later case.
    Morphometric data regarding the six more conspicuous chromosomes pairs are presented for the studied species, and their relationships comparatively discussed according to the resolution obtained.
    Download PDF (9941K)
  • C. K. Rudramuniyappa
    1985 Volume 50 Issue 4 Pages 891-898
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Total polysaccharides, RNA, proteins and ascorbic acid (AA) were localized histochemically in the developing sporogenous tissue and periplasmodium tapetum of Parthenium. Storage polysaccharides are not observed in the sporogenous tissue, meiocytes and in microspore tetrads. High contents of RNA and proteins present in the sporogenous tissue decline in the cytoplasm of the meiocytes. Young microspores show reduced contents of RNA and proteins which increase later when the microspores mature. The microspore wall, the exine and the diffused material accumulated around the microspores, all react green with azure B. AA content is rich in the sporogenous tissue, but it declines in the meiocytes. The microspores within the tetrad show varied quantity of AA. The tapetum exceptionally stores PAS positive and AA granules. RNA and proteins are also high in it. In the plasmodium the stored PAS positive and AA granules decline and lost whereas the RNA and proteins persist considerably in it. In the plasmodium all these histochemical constituents concentrate more around the microspores. The present study clearly recognized the storage nature of the periplasmodial tapetum.
    Download PDF (4370K)
  • Sharda Khandelwal
    1985 Volume 50 Issue 4 Pages 899-906
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Following are the important observations:
    1. The present study is a pioneer attempt to see the effect of magnetic field on the meiotic cell division of a lower vascular plant.
    2. The strength of magnetic field applied is 1.6×105 Gauss for one hour, which is of greater strength and for longer duration.
    3. The abnormalities can be explained on the bases of the effect of magnetic field in the change of tetrahedronal linking of C-C bond, viscosity, surface tension and circadian rhythm.
    Download PDF (9243K)
  • Tomosaburo Yabuno
    1985 Volume 50 Issue 4 Pages 907-912
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    A strain of Echinochloa species showing morphological similarity to E. crusgalli was collected in the lowland rice field in Peradeniya, Sri Lanka, This strain (strain no. 77-10) is characterized by the convex, coriaceous and lustrous lower lemma and the lower and upper glumes variegated with reddish or blackish purlple. These characteristics manifested dominantly in all the F1 hybrids produced in this study. Strain 77-10 is an annual and hexaploid with 2n=6x=54.
    Cytological data regarding the hybrids among three hexaploids, strain 77-10, E. colona and E. crus-galli, and tetraploid species E. oryzicola indicated that these three hexaploids are distantly related to each other, probably having a common genome.
    Download PDF (3554K)
  • K. Narayana Naidu, M. Edward Gururaj
    1985 Volume 50 Issue 4 Pages 913-919
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Chromosomal architecture of Megaderma lyra, a microchiropteran bat collected from South India, was analysed for the first time using G- and C-banding techniques. The diploid number, FN value and categorisation of autosomes were in confirmity with the previous report which utilised a North Indian population for analysis. However, variations with regard to the nature of the X and Y chromosomes were encountered in these two populations. The important feature noticed in the G-banded karyptype is the G-positive nature of thesatellite of the 8th pair of hetero-morphic autosomes and centromeric region of 5th, 6th, 7th and 18th autosomal pairs. The C-banded chromosomes revealed extensive occurrence of C-positive blocks of heterochromatin. The amount of heterochromatin (44.76%) measured for M. lyra is the highest for any bat studied till today. Present observations implicate pericentric inversion and addition or deletion of heterochromatin as causative agents for inter-population sex chromosome variations. It is also proposed that the high amount of consitiutive heterochromatin possibly had a role in the phylogenetic differentiation of this species.
    Download PDF (468K)
  • Shakuntala Nandi
    1985 Volume 50 Issue 4 Pages 921-926
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Two organic (ethyl mercuric chloride and mixture of ethyl mercuric chloride and phenyl mercuric acetate) and an inorganic (mercuric chloride) fungicides were tested on Allium cepa root tips. Different chromosomal aberrations were noted. Chromatid exchanges, breaks, ring chromosomes etc. showed strong mutagenic potentialities of these chemicals. Presence of polyploid cells indicated the role of fungicides in inhibiting spindle system. Binucleate cells appeared in low concentrations after long period of treatment indicating the action of the chemicals on the membrane system. These chemicals proved to be potential for causing genetic hazards in the biological system thereby justifying their banning in agriculture.
    Download PDF (2206K)
  • Bungo Wada
    1985 Volume 50 Issue 4 Pages 927-941
    Published: December 25, 1985
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Download PDF (3230K)
feedback
Top