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八种国产大戟属植物的核型报道

王彦红, 马金双, 刘全儒   

  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:1999-07-10 发布日期:1999-07-10
  • 通讯作者: 王彦红

Karyotypes of eight species of Euphorbia L. (Euphorbiaceae) from China

WANG Yan-Hong, MA Jin-Shuang, LIU Quan-Ru   

  • Received:1900-01-01 Revised:1900-01-01 Online:1999-07-10 Published:1999-07-10
  • Contact: WANG Yan-Hong

摘要:

8种大戟属Euphorbia L.植物的核型分析结果表明,大戟属不同亚属的染色体基数与其形态变
异的复杂性有一定关系。地锦草亚属subgen.Chamaesyce 3个种染色体基数分别为x=8,9,11;一品红
亚属subgen.Poinsettia两个种染色体基数均为x=7,分别为四倍体和八倍体;乳浆大戟亚属subgen.
Esula 3个种,染色体基数分别为x=7,10,10。根据以前学者发表的资料分析,一品红亚属和大戟亚属
Subgen. Euphorbia的染色体基数是很稳定的,分别为x=7和x=10;通奶草E.hypericifolia为x=8
的四倍体,它不仅有染色体整倍性的变异,还有异基数性的变化。结合以前学者的研究,笔者支持x=
10为大戟属的最原始基数的观点。齿裂大戟E.dentata和通奶草具不同的染色体倍性,猫眼草E.
esula的细胞染色体数目观察证实了我国存在四倍体的居群,与欧洲和北美的植物构成一个典型的多
倍体复合体。

关键词: 大戟属, 核型

Abstract:

In this paper, eight species of the genus Euphorbia L. were cytologically studied.
The three species of the subgenus Chamaesyce Raf., E. hirta, E. humifusa and E. hy-
pericifolia, had chromosome numbers of 2n = 18, 22 and 32, with their basic chromosome
numbers being x = 9, 11 and 8 respectively. The two species of the subgenus Poinsettia
(Grah.) House. E. dentata, with 2n=28, a tetraploid, and E. cyathophora, with 2n=
56, a octoploid, had both the basic chromosome number of x= 7. The three species of the
subgenus Esula Pers, E. lathyris, E. helioscopia and E. hylonoma, had chromosome
number of 2n= 20, 42 and 20, with their basic numbers being x= 10, 7 and 10 respectively.
The basic chromosome number of x = 8 is new for E. hypericifolia, in which x = 7 was pre-
viously reported. This indicates that this species had both ploidy(2n = 4x = 28, 8x = 56) and
dysploidy(x = 7, 8) variations. In E. dentata, there occurred also ploidy variation (2n =
2x, 4x and 8x). A tetraploid cytotype of E. esula was found in China, its diploid cytotype
and hexaploid cytotype being previously reported in North America, the Iberian Peninsula
and some other European areas. Based on our results and those previously reported, we sup-
port the viewpoint that x=10 may be the original basic chromosome number of Euphorbia
and discuss the role of polyploidy and dysploidy in the speciation and evolution of this genus.

Key words: Euphorbia, Karyotype