摘要:

Somatic chromosomes of a Siluroid fish,Rita chryseawere analysed from the kidney of 5 individuals by air-drying method and the diploid number was determined to be 54. There was no marker chromosome. The sex chromosomes were also unidentifiable. Metrical analysis comprising mean length with standard deviation, relative percentage length, centromeric index and arm-ratio for each chromosome was done and the morphology was determined from the centromeric index. The chromosomes were serially arranged and the karyotype formula wasn= 14m + 10 sm + 3 st.

ISSN:0008-7114    

DOI:10.1080/00087114.1977.10796698

出版商:Taylor & Francis    

年代:1977

数据来源: Taylor

摘要:

Structure and behaviour of chromosomes during spermatogenesis have been studied in seven species of Coprinae, viz.Catharsius molossus(L.),C. pithecius(Fabr.),Onthophagus ramosellusBates,O. mopsus(Fabr.),O. catta(Fabr.),O. quaestusSharp, andOnitis philemonFabr. All the species uniformally show 2b=20. Male sex chromosome mechanism is Xyp type butC. molossus(L.) also shows Xyr. Y is metacentric and shows much variation in size. There is a diffuse diplotene inO. catta(Fabr.). Ring bivalents were observed inO. ramosellusBates andO. quaestusSharp. Evolution of Karyotype in Coprinae has been discussed.

ISSN:0008-7114    

DOI:10.1080/00087114.1977.10796699

出版商:Taylor & Francis    

年代:1977

数据来源: Taylor

摘要:

Two populations ofPsilotum nudumgrowing wild in Western Ghats and Central India have been cytologically investigated for pairing behaviour of chromosomes during meiosis. The two populations have been found to be 6x and 9x. They are presumed to have arisen through autopolyploidy and auto-alloploidy. The counts and reports are new records in this ancient group of living vascular plants.

ISSN:0008-7114    

DOI:10.1080/00087114.1977.10796700

出版商:Taylor & Francis    

年代:1977

数据来源: Taylor

摘要:

Using Feulgen's method and light microscopy, an extensive cytogenetical study concerning nuclear and chromosomal structure, mitosis and meiosis in mesokaryotic algae was performed. A tentative karyotype in a mesokaryotic alga has been done for the first time. A particular mechanism of sexuality in which an unidirectional transfer of genetic material takes place is described inPeridinium trochoideum.The behaviour of eukaryotic nucleus in the division process ofP. balticum, P. tabulatumandP. trochoideumis also described. It is concluded that eukaryotic nucleus may represent a parasite of genetic level.

ISSN:0008-7114    

DOI:10.1080/00087114.1977.10796701

出版商:Taylor & Francis    

年代:1977

数据来源: Taylor

摘要:

The meiotic process in Dinoflagellates is performed by a dinomitosis mechanism. The sexual process is done by isogamy or alternatively by anisogamy.

ISSN:0008-7114    

DOI:10.1080/00087114.1977.10796702

出版商:Taylor & Francis    

年代:1977

数据来源: Taylor

摘要:

The presence of two kinds of nuclei—one mesokaryotic, the other one eukaryotic—in different species of Dinoflagellates is described. Due to high synchrony in their division, close spatial relationships between them, as well as to some chromosomal structural alterations in mesokaryotic nucleus, it was concluded that there is an parasitical phenomenon of genetic level.

ISSN:0008-7114    

DOI:10.1080/00087114.1977.10796703

出版商:Taylor & Francis    

年代:1977

数据来源: Taylor

摘要:

Observations are described on the nuclear behaviour relative to the chlamydospore germination, sporogenesis andin vitrochlamydospore development inProtomycopsis pateliiPavgi and Thirumalachar andProtomycopsis thirumalachariiPavgi, respectively parasitic onPhaseolus mungoL. andSesbania grandifloraPers. Taxonomy and phylogenetic relationship of the genusProtomycopsisMagnus and family Protomycetaceae are discussed in the light of these observations.

ISSN:0008-7114    

DOI:10.1080/00087114.1977.10796704

出版商:Taylor & Francis    

年代:1977

数据来源: Taylor

摘要:

Karyotypes of six species (one of the six species is represented by three subspecies) of the treefrogs (Rhacophoridae) were described and compared. All species have 2n=26 chromosomes consisting of five large and eight small chromosome pairs, indicating a close relationship between Rhacophoridae and Ranidae. Karyological as well as ecological comparisons suggest the three groups; (1)Rhacophorus schlegelii, R. viridis amamiensis, R. v. viridis, andR. v. owstoni, (2)R. buergeri, R. robustus, andR. japonicus, and (3)R. eiffingeri.These groupings are consistent with those on the morphological bases.

ISSN:0008-7114    

DOI:10.1080/00087114.1977.10796705

出版商:Taylor & Francis    

年代:1977

数据来源: Taylor

ISSN:0008-7114    

DOI:10.1080/00087114.1977.10796706

出版商:Taylor & Francis    

年代:1977

数据来源: Taylor

摘要:

Induction of desynaptic behaviour in a variant isolated from erectly oriented fruit variety ofCapsicum annuumfollowing 20 kR gamma irradiation was observed. The phenomenon led to the production of numerous interesting meiotic anomalies such as micronuclei y miniatures, polyspory and finally gametes with varying degree of genetic imbalance.

ISSN:0008-7114    

DOI:10.1080/00087114.1977.10796707

出版商:Taylor & Francis    

年代:1977

数据来源: Taylor