摘要:

The karyotype ofZ. pendulavar.quadricolor(2n23,n.f.= 28) is shown to have 6M + 7A+10T chromosomes. This variety is suggested to have evolved from Z.pendula, having 4M+8A+12T chromosomes, by two simultaneous centric fusions, involving two T chromosomes, the satellited A chromosome and another A chromosome, resulting in the two additional M chromosomes and the newly formed satellited A chromosome ofZ. pendulavar.quadricolor.The satellited A chromosome of the variety is suggested to have been formed from the short arms of the two A chromosomes ofZ. pendula.

ISSN:0008-7114    

DOI:10.1080/00087114.1981.10796899

出版商:Taylor & Francis    

年代:1981

数据来源: Taylor

摘要:

Metaphase analyses in suspension cultures ofHaplopappus gracilisand callus and suspension cultures ofVicia hajastanashowed evidence of extensive alterations in chromosome structure. Anaphase analyses showed very low frequencies of lagging chromosome, multipolar divisions and unequal separation of chromatids; fragments and chromatin bridges were present in relatively high frequencies. It is concluded that the majority of aneuploid cells in these cultures were produced by elimination of chromosomes through a gradual loss of chromatin by fragmentation and chromatin bridges.

ISSN:0008-7114    

DOI:10.1080/00087114.1981.10796900

出版商:Taylor & Francis    

年代:1981

数据来源: Taylor

摘要:

Cytological and morphological details of an autotriploid ofCoffea canephoraare reported. Cytological studies showed a marked difference to earlier reports on triploids of interspecific origin thereby indicating the present triploid as intraspecific in origin. Morphologically it differed from the normal diploid in characters such as reduced internodal length, stomatal number per unit area and partial increase in palisade parenchyma. Possibility of obtaining a progeny is discussed.

ISSN:0008-7114    

DOI:10.1080/00087114.1981.10796901

出版商:Taylor & Francis    

年代:1981

数据来源: Taylor

摘要:

Karyological investigations were made on two taxa ofSirogoniumKutzing. The chromosome numbers reported in the present study are found to ben= 8 forS. inflatumandn= 50 ± 2 forS. reticulatum.These two chromosome numbers obtained forS. inflatumandS. reticulatumare first reports.

ISSN:0008-7114    

DOI:10.1080/00087114.1981.10796902

出版商:Taylor & Francis    

年代:1981

数据来源: Taylor

摘要:

A new one-step method for SCE visualization after BrdU incorporation, using prolonged hydrolysis and the Feulgen reaction, has been developed. InVicia fabait gives essentially the reserve of the FPG technique with darker stained double-substituted chromatids. Besides harlequin chromosomes, the new method reveals bands in the approximate position of known heterochromatic segments, and also asymmetric bands after one round of replication in the presence of BrdU.

ISSN:0008-7114    

DOI:10.1080/00087114.1981.10796903

出版商:Taylor & Francis    

年代:1981

数据来源: Taylor

摘要:

Variation in chiasma frequency and distribution was investigated in six sympatric populations ofCepaea nemoralisandC. horlensissampled from a geographically restricted area of SW Devon, England. The results are compared with those obtained from a different area. The mechanics of chiasma frequency variation are similar in the two species in both areas. However, the statistics differ both between species and between areas. The significance of this is discussed.

ISSN:0008-7114    

DOI:10.1080/00087114.1981.10796904

出版商:Taylor & Francis    

年代:1981

数据来源: Taylor

摘要:

The C- and G-band patterns ofMicrotus nivalismetaphase chromosomes are described. The C-band pattern shows only centromeric C-bands in every autosome and reveals that the Y-chromosome is a medium sized element. No hetero- chromatic blocks were observed. All autosome pairs can be identified by its characteristic G-band pattern. This results are discussed with those obtained by several authors.

ISSN:0008-7114    

DOI:10.1080/00087114.1981.10796905

出版商:Taylor & Francis    

年代:1981

数据来源: Taylor