星果草属、独叶草属、鸡爪草属的染色体观察和系统位置的探讨

中国科学院大学学报

星果草属、独叶草属、鸡爪草属的染色体观察和系统位置的探讨

张芝玉

(中国科学院植物研究所)

收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:1982-11-18 发布日期:1982-11-18
通讯作者: 张芝玉

Chromosome observations of three ranunculaceous genera in relation to their systematic positions

Zhang Zhi-Yu

(Institute of Botany, Academia Sinica)

Received:1900-01-01 Revised:1900-01-01 Online:1982-11-18 Published:1982-11-18
Contact: Zhang Zhi-Yu

摘要/Abstract

Abstract:

1. The present paper describes the observations of chromosome numbers and

karyomorphology of 2 species of 2 endemic genera and I endemic species of Chinese

Ranunculaceae: Asteropyrum peltatum (Franch.) Drumm et Hutch. 2n=16, x=8;

Kingdonia unifolia Balf. f. et W. W. Sm. 2n=18, x=9 and Calathodes oxycarpa Spra-

gue 2n=16, x=8. The chromosome counts of three ranunculaceous genera are repor-

ted for the first time.

2. The morphylogical, palynological and cytological date in relation to the syste-

matic postition of Asteropyrum, Kingdonia and Calathodes within the family Ranun-

culaceae are diseussed and resulted in following conclusions:

(1). On the basis of the basic number x=8 in Asteropyrum, it is further con-

firmed that this genus is distinct from the r elated genera such as Isopyrum, Dichocarp-

um and other allied taxa.

The comparison of Asteropyrum with Coptis shows that they are identical in short

chromosomes, with magnoflorina and benzylisaquinodine type of alkaloides, but dif-

ferent from coptis in the chromosome numbers (T-type), pantocolpate pollens, united

carpels and the dorsi-ventral type of petioles. In view of these fundamental morpho-

logical and cytological differences, Asterop yrum is better raised to the level of Tribe.

However Asteropyrum and Coptis may represent two divaricate evolutional lines of

Thalictroideae.

(2). The systematic position of the genus Kingdonia has been much disputed in

the past. We support the view of Sinnote (1914), namely, the trilacunar in leaf

traces “the ancient type”, appeared in the angiosperm line very early, while the uni-

lacunar of Kingdonia may be derived from the trilacunar. On the basis of the chromo-

some numbers and morphylogical observation, the present writer accept Tamura’s and

Wang’s treatment by keeping Kingdonia in Ranunculaceae instead of raising it to a

family rank as has been been done by Forster (1961). Kingdonia and Coptis are

similar in having short chromosome with x=9, but with one-seeded fruits; therefore it

is suggested that placed into Thalictroideae as an independent tribe, indicating its close

relationship with Coptideae.

(3). Comparing with its allies, Calathodes being with out petals, seems to be more

primitive than Trollius. But Calathodes differs from Trollius with R-type chromosomes in having T-type chromosome with x=8 and subterminal centromere. Those charac-

teristics show that it is very similar to the related genera of Thalictroideae. But as

Kurita already pointed out that most speci es of Ranunculus have usually large long

chromosomes but some species have compar ativelly short chromosomes, therefore we

regard T-type and R-type chromosomes appear independently in different subfamilies

of Ranunculaceae. According to Tamura, G alathodes seems to be closely related to

Megaleranthis, because of the resemblance in follicles. But due to lack of cytological

data of the latter genus, the relationship between the two genera still is not clear pen-

ding further studies. From the fact that the morphology and chromosomes of the

Calathodes differs from that of all other genera of the Helleboroideae, we consider

Calathodes may form an independent tribe of its own with a closer relationship with

Trollieae.

张芝玉. 星果草属、独叶草属、鸡爪草属的染色体观察和系统位置的探讨[J]. 中国科学院大学学报.

Zhang Zhi-Yu. Chromosome observations of three ranunculaceous genera in relation to their systematic positions[J]. .