全 文 ：英文稿
KARYOTYPE STUDIES ON LUZHOU (SICHUAN)
PTEROCYPSELA INDICA (COMPOSITAE) *
Cai Shiyu, Gong Shu, Mei Zhiqiang, Yu Haiqing
Research Center for Preclinical Medicine, Medicinal Botanical Association of Zhongshan, Luzhou Medical College
Abstract Objective： To obtain the chromosome numbers and karyotype of Luzhou (Sichuan) Pterocypsela
indica. Methods: Seeds of P. indica were germinated 22℃ in the dark. Root tips were pretreated in an ice bath,
fixed in Carnoys fixative Ⅰ, and treated in 1 M HCl at 60℃ in a water bath. Somatic cells were stained in Schiff
and the meristematic portions of the root tips were squashed in 45% acetic acid. Microphotographs were taken
from metaphase cells by optical microscope. Results: The chromosome numbers of P. indica were 18, and the
karyotype formula was 2n= 2x= 18= 6m+10sm+2st. The relative length of chromosomes ranged in size from 8.61
to 13.92. The index of the karyotypic asymmetry was 67.60. Conclusion： The karyotype of Luzhou P. indica is
3A type. There are variations in chromosomal parameters and characteristics between Luzhou P. indica and other
populations. The karyotype differentiations are related to their wide distributions and different habitats perhaps.
The subterminal centromere indicated that Luzhou P. indica is most likely more evolved populations.
Key words Compositae; Pterocypsela indica; Karyotype formula; Subterminal centromere
CLC Number Q342.2+2 Document Code A Article ID 1000-2669（2011）5-0663-03
四川泸州翅果菊的核型研究
蔡仕钰，龚 舒，梅志强，于海清
（泸州医学院：医学基础研究中心；忠山药用植物协会，四川泸州 646000）
摘 要 目的：研究四川泸州中药翅果菊的染色体数目和核型。 方法：翅果菊种子 22℃暗培养，根尖经冰水混合物预处理，卡
诺氏固定液Ⅰ固定，1 M HCl 60℃解离。希夫试剂染色，分生组织区用 45%乙酸制片，中期细胞光镜观察照相。结果：泸州翅果菊
的染色体数目为 18，核型公式为 2n= 2x =18 = 6m + 10sm + 2st。染色体相对长度范围 8.61~13.92，核型不对称系数为 67.60。结
论：四川泸州翅果菊核型类型属于 3A 型，不同于已报道的翅果菊居群，核型分化极可能与翅果菊物种的广布和生境不同有关。
近端部着丝点表明泸州翅果菊属于较为进化的类群。
关键词 菊科；翅果菊；核型公式；近端部着丝粒
中图分类号 Q342.2+2 文献标识码 A 文章编号 1000-2669（2011）6-0663-03
*Supported by the grants from the Youth Foundation, the National Natural Science Pre-Research Foundation and the Scientific
Research Starting Foundation for Doctors of Luzhou Medical College (No. 676, 409 and 606).
Biography: Cai Shiyu (1988- ), Male, Bachelor
Corresponding author: Yu Haiqing (1978- ), Male, Associate professor
Pterocypsela indica (L.) Shih in genus Ptero-
cypsela Shih is a traditional medicinal herb widely
distributed in China, except for the Northwestern re-
gion,with different habitats,such as hillsides, fields,
wastelands and roadsides [1]. The whole herb of P. indi-
ca is effective in eliminating toxicant, reducing in-
flammation, regulating hemostasis and invigorating
stomach[1,2].
第 6 期 Cai shiyu，et al:Karyotype studies on luzhou (sichuan) pterocypsela indica (compositae) 663
泸州医学院学报 2011 年 第 34 卷 第 6 期
Journal of Luzhou Medical College Vol.34 No.6 2011
3 Discussion
In the present study, the chromosomal numbers of
P. indica in Luzhou (Sichuan province) were 18. The
result was accordant with the previous cytological data
[1~2,5]. The kayotype of Luzhou P. indica belongs to 3A
type, which is similar to those of P. indica populations
in Qian Mountain (Liaoning province) and Emei
Mountain (Sichuan province) respectively [2,5]. However,
it is obviously different to that of P. indica in Qianfo
Species
P. indica
Karyotype formula
2n = 2x = 18 = 6m + 10sm + 2st
A. A. R
2.23
Lc/Sc
1.62
P. C. A
0.67
As. k (%)
67.60
Karyotype type
3A
The chromosomal numbers and karyotype analysis
from different populations are helpful in revealing
phylogenetic relationships and evolution of species [3，4].
The karyotypes of three different P. indica populations
have been reported[1，2,5]. However, little is known about
those of Luzhou P. indica populations in Sichuan
province. To obtain more cytological data, we have in-
vestigated the chromosomal numbers and karyotype of
Luzhou P. indica and discuss the karyotype evolution
in the present study.
1 Materials and methods
The P. indica materials used in this study were
collected from Northern City Campus of Luzhou Medi-
cal College by present authors. The seeds were germi-
nated and grown in the perennial nursery of Medicinal
Botanical Garden, Luzhou Medical College. The ma-
ture plants were carefully identified by Dr. Yu
Haiqing. The voucher specimens (accession number
PITY2010001) have been deposited at the Medicinal
Botanical Association of Zhongshan (MBAZ), Luzhou
Medical College.
Seeds were scarified and germinated in Petri
dishes at 22℃ without filter paper. Root tips were ob-
tained from roots that were about 1.2 cm in length and
pretreated in an ice bath for 24 h before fixation in a
mixture of 95% ethanol: glacial acetic acid (3∶1, v/v)
for 24 h. They were then treated for 8 min in 1 mol/L
HCl at 60℃ in a water bath. Somatic cells were
stained in Schiff at room temperature for about 30
min. The meristematic portions of the root tips were
squashed in 45% acetic acid. Microphotographs were
taken from metaphase cells with a complete chromo-
some complement by the Motic BA200 camera system.
At least five metaphase cells were analyzed for the
taxon [6]. Idiogram was constructed based on the chro-
mosome lengths and relative arm ratios. Index of the
karyotypic asymmetry and karyotype type analyses
were basically the same as described by Arano [7] and
Stebbins[8] respectively.
2 Results
Chromosomal parameters and characteristics are
listed in Table 1 and Table 2 respectively. The mor-
phology of somatic chromosomes, karyotypes and idio-
grams are shown in Fig. 1 (A-C). Results of karyotype
analysis of Luzhou P. indica are presented below.
The karyotype formula is 2n = 2x = 18 = 6m +
10sm + 2st, which belongs to 3A type. The average
arm ratio is 2.23, with a longest chromosome/shortest
chromosome ratio of 1.62. Percentage of chromosomes
with the arm ratio >2 is 0.67, and index of the kary-
otypic asymmetry is 67.60 (Table 2). The relative
length of chromosomes ranges in size from 8.61 to
13.92 (Table 1). Most of the chromosomes are meta-
centric or submetacentric, while homologous chromo-
somes 4 are acrocentric (Table 1, Fig. 1, A-C).
Table 1 Chromosomal parameters of P. indica in the kary-
otype analysis
Species
P. indica
Chromosome No.
1
2
3
4
5
6
7
8
9
Relative length
9.53+4.39=13.92
9.94+3.40=13.34
8.12+3.98=12.10
8.95+2.40=11.35
6.63+4.23=10.86
5.88+4.56=10.44
5.80+4.39=10.19
6.55+2.65=9.20
6.21+2.40=8.61
Arm ratio
2.17
2.92
2.04
3.73
1.57
1.29
1.32
2.47
2.59
Chromosome type
sm
sm
sm
st
m
m
m
sm
sm
Table 2 Chromosomal characteristics of P. indica in the karyotype analyses
Notes：A. A. R = Average arm ratio; Lc = longest chromosome; Sc = shortest chromosome; P. C. A = Percentage
of chromosomes with arm ratio >2; As. k (%) = Index of the karyotypic asymmetry
664
Fig 1.Chromosomes morphology,karyotype and idiogram of P.indica
A, Morphology of P. indica somatic
chromosomes. Bar equals 10 μm
B:Karyotype of P. indica. The numbers indicate the chro-
mosome numbers
C：Idiogram of P. indica.The numbers in horizontal and
vertical directions indicate the chromosome numbers and relative
lengths of chromosomes respectively
Mountain (Shandong province) [1].
The karyotype formula of Luzhou P. indica is
closely similar to that of Ermei Mountain P. indica, es-
pecially in their metacentric, submetacentric and acro-
centric chromosome numbers[5]. Yuan and Yang[5] found
that one pair of satellites is located on the short arms
of chromosomes 8 in Ermei Mountain P. indica, while
no satellite is demonstrated among chromosomes of P.
indica populations in Luzhou, Qian Mountain or Qianfo
Mountain [1，2]. Furthermore, the index of the karyotypic
asymmetry and average arm ratio of Luzhou P. indica
are nearly identical to those of Qian Mountain and E-
mei Mountain populations respectively[2,5].
The variations in chromosomal parameters and
characteristics of P. indica populations might be due
to different methodologies. On the other hand, these
variations show that the kayotypes of Luzhou P. indica
and others are differentiated from each other. These
differentiations are related to their wide distributions
and different habitats perhaps. In the present analysis,
the acrocentric chromosomes were revealed in kary-
otypes of Luzhou and Ermei Mountain P. indica dis-
tributed in Sichuan province. Stebbins[8] indicated that
nonsymmetrical karyotype characteristics are common-
ly found in higher plants. Therefore, Luzhou P. indica
is closely related to Ermei Mountain P. indica, and
they are most likely more evolved populations.
Acknowledgements
The authors contribute equally to the present work.
We are thankful to the Youth Foundation, the National
Natural Science Pre-Research Foundation and the Sci-
entific Research Starting Foundation for Doctors of
Luzhou Medical College (No. 676, 409 and 606).
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第 6 期 Cai Shiyu，et al:Karyotype studies on Luzhou (Sichuan) pterocypsela indica (compositae) 665