A Karyomorphological Study of Cephalotaxaceae

GU Zhi-Jian, ZHOU Qi-Xing, YUE Zhong-Shu

Received:1900-01-01 Revised:1900-01-01 Online:1998-01-10 Published:1998-01-10
Contact: GU Zhi-Jian

Abstract:

The present paper has investigated the karyomorphology of 4 species in the

Cephalotaxaceae for the first time. The morphology of interphase nuclei of all these species

was found to belong to the complex chromocenter type, to be with a big dark-stained chro-

matin block which lies in one side of cells and many dark-stained chromatin particles evenly

distributed in the cells. And the somatic chromosomes at mitotic prophase of these species

belong to the interstitial type, contain many heterochromatic and euchromatic segments ar-

ranged one after another. The karyotypes of metaphase chromosomes were formulated to be

K2n=24=21m＋1M＋2sm(2SAT) for C.fortunei,K2n=24=19m＋3M＋2sm(2SAT)

for C.alpina, K2n=24=22m＋2sm(2SAT) for C.oliveri, and K2n=24=22m(1SAT)

＋2sm(2SAT) for C.mannii. The karyotype asymmetry of C.fortunei, C.alpina and

C. mannii was all of 2A type, except that of C. oliveri being 2B type. The centromeric

terminalization value (T.C. %) was 53.99% for C. fortunei, 53.93% for C. alpina,

54.47% for C. mannii and 53.53% for C. oliveri respectively. The four species in the

Cephalotaxaceae share the similar karyotype at the metaphase stage, in which No.1 to

No.22 were mchromosomes (including Mchromosomes), and No.23 to No.24 were sm

chromosomes with satellites on their short arms. As these two smchromosomes with satel

lites were stable and obvious, we consider them as chromosomes typical of the Cephalotaxac

eae. Nevertheless there also exist differences among the four species, i.e. No.22 mchromo

some of C.mannii still having a satellite on its short arm, while there were no satellites on

the short arms of the other three species. In addition, the number and location of secondary

constriction of the other three species are different from each other, but no satellites were ob

served in C. alpina because of the extreme contraction of the chromosomes. From the kary-

otypic parameters mentioned above, C. fortunei and C. alpina have the closest relation-

ship.

Key words: Cehalotaxaceae, KaryomophOlogy

GU Zhi-Jian, ZHOU Qi-Xing, YUE Zhong-Shu. A Karyomorphological Study of Cephalotaxaceae[J]. .

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