作 者 ：GU Zhi-Jian, ZHOU Qi-Xing, YUE Zhong-Shu
期 刊 ：植物分类学报 1998年 1期
Keywords:Cehalotaxaceae, KaryomophOlogy,
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.