全 文 ：Chromosomal Karyotypes of Fragaria Plants
SHI Cui-ping1* ，NIU Shu-qi2，GE Hui-bo3
1． College of Life Science，Agricultural University of Hebei，Baoding 071000; 2． Landscape and Forestry Bureau of Baoding City，Baoding
071000; 3． Forestry Bureau of Hebei Province，Shijiazhuang 050000
Abstract ［Objective］This study was to analyze the karyotypes of wild diploid strawberry species，so as to provide basis for revealing the ori-
gins，evolvement and genetic breeding of strawberry． ［Method］ Four diploid strawberry species including Fragaria gracilis A． Los，Fragaria
nilgerrensis Schidl，Fragaria pentaphylla A． Los． and Fragaria vesca L． were used as experimental materials to analyze their chromosomal kary-
otypes． ［Result］The karyotype formula for strawberry species tested was as follows: 2n =2x =14 =10m +2sm +2m* for F． gracilis A． Los，
belonging to type 1B; 2n =2x =14 =14m for F． nilgerrensis Schidl，belonging to type 1A; 2n =2x =14 =12m +2sm for F． pentaphylla A． Loz．，
belonging to type 1A; 2n =2x =14 =14m for F． vesca L．，belonging to type 1A． Karyotype analysis showed that karyotypic asymmetry degree of
the four species was F． gracilis A． Los． ＞F． pentaphylla A． Loz． ＞ F． vesca L． ＞ F． nilgerrensis Schidl． ［Conclusion］The evolution order of
these four species was probably F． gracilis A． Los．，F． pentaphylla A． Loz．，F． vesca L．，F． nilgerrensis Schidl．
Key words Strawberry; Karyotype analysis; Diploid
Received: January 18，2011 Accepted: February 10，2011
Supported by Program for Excellent Scholars Returned from Overseas．
* Corresponding author． E-mail: shicp2006@126． com
Strawberry genus，Fragaria ( Rosaceae ) ，has a base
chromosome number of x =7． Fragaria plants contain approxi-
mately 50 species in the nature，of them most wild species
are diploid，some are tetraploid，pentaploid，octoploid，and
cultivars all belong to octoploid［1］． However，it has been poor-
ly understood at cell biology level． Y． Jwatsubo et al．［2］ ana-
lyzed the karyotypes of three strawberry species F． iinumae，
F． nipponica and F． vesca in 1989，and CHEN Rui-yang et
al［3］ studied the karyotype of F． × ananassa Duch． in 1993．
There are many troubles encountering chromosomes slide
preparation of strawberry which belongs to minitype species，
such as shorter pretreatment duration，longer enzymatic hy-
drolysis，less hydrolysis products and hard preparation of
good slides compared with other species like Chinese date
and grape． In view of this，we analyzed karyotypes of several
diploid wild strawberry species，aiming at providing basis for
revealing the origins，evolvement and genetic breeding of
strawberry．
Materials and Methods
Four diploid wild strawberry species sampled from speci-
men gardens of Agricultural University of Hebei and Shenyang
Agricultural University were used as experimental materials．
These materials were cultivated in the bare field，stewarded
according to routine field method and covered with plastic film
for overwintering before winter．
The tips of shortened stems or stolons were pretreated
with 0． 002 mol /L 8-hydroxyl quinoline for 2 －3 h，immersed in
0． 075 mol /L KCl solution with 30 min for low osmotic treat-
ment and mobilized in methanol-ice acetic acid ( 3 ∶1 ) over-
night． Stem tip meristem was isolated and added to complex
enzyme solution( 2．5% cellulase +2． 5% pectinase) with 3． 5 －
4． 0 h for hydrolysis，rinsed with ddH2O and then subjected to
low osmotic treatment for 15 min． Clean frozen slides were
flame-dried for coating with above treated materials． The
slides coated were stained with Giemsa for 15 min and then
observed under Olympus microscope for taking pictures． Re-
sult of each slide was presented with the mean of five cells．
Karyotype analysis was performed using the classification cri-
terion described in reference［4］．
Results and Analysis
Relative length and arm ratio were determined according
to chromosome shape and magnified version of microscopic
picture for matching analysis． Karyotype parameters of the
strawberry species tested were listed in Table 1 and their
types and karyotypes in Fig． 1 －4．
Fig． 1 Chromosomal karyotype analysis on F． gracilis A． Los
Fig． 2 Chromosomal karyotype analysis on F． nilgerrensis
Schidl
Table 1 indicates the karyotype characteristics of the spe-
cies and varieties of strawberry plants as follows:
Agricultural Basic Science and Method
Agricultural Science ＆ Technology，2011，12( 1) : 8 －10
Copyright 2011，Information Institute of HAAS． All rights reserved．
DOI:10.16175/j.cnki.1009-4229.2011.01.030
Fig． 3 Chromosomal karyotype analysis on F． pentaphylla A．
Los
Fig． 4 Chromosomal karyotype analysis on F． vesca L．
Table 1 Chromosomal karyotype analysis of strawberry species tested
Species ChromosomeNo．
Relative length
( short arm +
long arm =
length)
Arm ratio
( long
arm /short
arm)
Type
F． gracilis 1 5． 97 +4． 77 =10． 74 1． 25 m
A． Los． 2 4． 07 +3． 36 =7． 43 1． 21 m
3 4． 38 +2． 56 =6． 94 1． 71 m
4 3． 62 +3． 14 =6． 76 1． 15 m
5* 3． 80 +2． 92 =6． 71 1． 30 m
6 3． 31 +3． 05 =6． 36 1． 09 m
7 3． 09 +2． 12 =5． 21 1． 46 m
F． nilgerrensis 1 5． 61 +4． 35 =9． 96 1． 29 m
Schidl 2 4． 72 +3． 89 =8． 61 1． 21 m
3 4． 09 +3． 24 =7． 33 1． 26 m
4 3． 72 +3． 04 =6． 76 1． 22 m
5 3． 83 +2． 58 =6． 41 1． 48 m
6 3． 21 +2． 73 =5． 94 1． 18 m
7 2． 75 +2． 41 =5． 16 1． 14 m
F． pentaphylla 1 5． 41 +4． 39 =9． 80 1． 23 m
A． Loz． 2 4． 25 +4． 06 =8． 31 1． 05 m
3 4． 54 +3． 62 =8． 16 1． 25 m
4 3． 67 +3． 19 =6． 86 1． 15 m
5 4． 15 +2． 32 =6． 47 1． 79 m
6 2． 90 +2． 37 =5． 27 1． 22 m
7 2． 66 +2． 51 =5． 17 1． 06 m
F． vesca L． 1 5． 06 +4． 53 =9． 59 1． 12 m
2 4． 63 +3． 99 =8． 62 1． 16 m
3 3． 99 +3． 18 =7． 17 1． 25 m
4 3． 74 +2． 92 =6． 66 1． 28 m
5 3． 96 +2． 68 =6． 64 1． 48 m
6 3． 17 +2． 89 =6． 06 1． 10 m
7 3． 31 +1． 96 =5． 27 1． 69 m
F． gracilis A． Los． belongs to diploid with the karyotype
formula of 2n =2x =14 =10m +2sm +2m( SAT) ． Of its chro-
mosomes，the fifth pair is the random chromosome and has a
mid-centromere( m) ; the third one is submedian region chro-
mosome ( sm) ; all other five are median region chromosome
( m) ． The parameters of F． gracilis A． Los． are as follows:
absolute length range is 0． 55 －1．34 μm，relative length varia-
tion range is 10． 74% － 5． 21% ; arm ratio range is 1． 71 －
1．09; ratio of longest chromosome to shortest chromosome
2．06，number of chromosome with an arm ratio higher than 2
is 0，classification of karyotype is 1B．
F． nilgerrensis Schidl． belongs to diploid with the karyo-
type formula of 2n = 2x = 14 = 14m． All its seven chromo-
somes are median region chromosome( m) ． The parameters
of F． nilgerrensis Schidl． are as follows: absolute length
range is 1． 37 － 0． 45 μm; relative length variation range is
9． 96% －5．16% ; arm ratio range is 1． 48 －1． 14; ratio of lon-
gest chromosome to shortest chromosome 1． 93; number of
chromosome with an arm ratio higher than 2 is 0; classifica-
tion karyotype is of 1A．
F． pentaphylla A． Loz． belongs to diploid with the karyo-
type formula of 2n = 2x = 14 = 12m + 2sm． Of its chromo-
somes，the fifth pair is submedian region chromosome ( sm) ;
all other six are median region chromosome( m) ． The param-
eters of F． gracilis A． Los． are as follows: absolute length
range is 1． 56 － 0． 52 μm; relative length variation range is
9． 80% －5．17% ; arm ratio range of 1． 79 －1．05; ratio of lon-
gest chromosome to shortest chromosome 1． 89，number of
chromosome with an arm ratio higher than 2 is 0，classifica-
tion karyotype is of 1A． F． vesca L． belongs to diploid with
the karyotype formula of 2n = 2x = 14 = 14m． All its 14 chro-
mosomes are median region chromosome( m) ． The parame-
ters of F． vesca L． are as follows: absolute length range is
1． 37 －0． 67 μm; relative length variation range is 9． 59% －
5．27% ; arm ratio range is 1． 69 －1．10; ratio of longest chro-
mosome to shortest chromosome 1． 82; number of chromo-
some with an arm ratio higher than 2 is 0，classification of kar-
yotype is 1A．
Conclusion and Discussion
Based on karyotype symmetry theory proposed by Levitz-
ky，Stebbins［5］ classified karyotypes into 12 types，i． e．，1A
to 4A，1B to 4B，1C to 4C，according to the proportion of the
number of chromosomes with arm ratio higher than 2 and the
length ratio of longest chromosome and shortest chromo-
some． Of the 12 types，1A is the most symmetrical type，4C
is the most anisomerous type． He also put forward that the
karyotypes of phanerogam has a trend of anisomerous evolu-
tion． Species with symmetrical karyotype always have original
traits，while that with anisomerous karyotype are usually the
evolved or derived species． According to this，F． gracilis A．
Los． belongs to 1B，and F． pentaphylla A． Loz．，F． vesca L．
and F． nilgerrensis Schidl． all belong to 1A． Of the species
tested，F． gracilis A． Los． is most anisomerous，followed by
F． pentaphylla A． Loz．，F． vesca L． which has a pair of sub-
median region chromosome ( sm) ． All chromosomes of F．
vesca L． and F． nilgerrensis Schidl． are median region chro-
mosome( m) ，with a mean arm ratio of 1． 30 and 1． 25 re-
spectively． Karyotypic asymmetry degree of the four species
was F． gracilis A． Los． ＞F． pentaphylla A． Loz． ＞F． vesca L． ＞
F． nilgerrensis Schidl． In conclusion，the evolution order of
these four species was probably F． gracilis A． Los．，F． pen-
taphylla A． Loz．，F． vesca L．，F． nilgerrensis Schidl．
9SHI Cui-ping et al． Chromosomal Karyotypes of Fragaria Plants
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［2］JWATSUBO Y，NARUHASHI． Karyotypes of three Fragaria ( Rosa-
ceae) ［J］． Cytologia，1989，54: 493 －497．
［3］CHEN RY，LIN SH，SONG WQ，et al． Chromosome atlas of Chi-
nese principal economic plants［M］． Beijing: International academ-
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［4］LI MX( 李懋学) ，CHEN RY( 陈瑞阳) ． A suggestion on the stand-
ardization of karyotype analysis in plants( 关于植物染色体核型分析
的标准化问题) ［J］． Journal of Wuhan Botanical Research( 武汉植
物学研究) ，1985，3( 4) : 297 －302．
［5］STEBBINS GL． Chromosomal evolution in higher plant［J］． Lon-
don: Edward Arnold Ltd．，1971: 87 －89．
Responsible editor: DUAN Yong-bo Responsible proofreader:
檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪檪
WU Xiao-yan
草莓属植物染色体核型分析( 摘要)
时翠平1* ，牛树启2，葛会波3 ( 1．河北农业大学生命科学学院，河北保定 071000; 2．河北省保定市园林局，河北保定 071000; 3．河北省
林业局，河北石家庄 050000)
［目的］分析二倍体野生种草莓的核型，为探讨草莓的起源、进化及遗传育种研究提供依据。
［方法］对草莓属( Fragaria) 植物 4个二倍体种森林草莓( F． vesca L． ) 、纤细草莓( F． gracilis A． Los． ) 、黄毛草莓( F． nilgerrensis Schidl) 和五
叶草莓( F． pentaphylla A． Los． ) 进行了核型分析。
［结果］纤细草莓的核型为 2n =2x =14 =10m +2sm +2m* ，属 1B类型;黄毛草莓为 2n =2x =14 =14m，属 1A类型;五叶草莓为 2n =2x =14 =
12m +2sm，属 1A类型;森林草莓为 2n =2x =14 =14m，属 1A类型。
［结论］草莓二倍体及品种核型对称性为:黄毛草莓 ＞森林草莓 ＞五叶草莓 ＞纤细草莓，供试草莓种的新缘进化顺序可能为黄毛草莓、森林草
莓、五叶草莓、纤细草莓。
关键词 草莓;核型分析;二倍体
基金项目 国家教委归国留学人才基金资助项目。
作者简介 时翠平( 1975 － ) ，女，河北灵寿人，硕士，讲师，从事植物抗逆生理研究。Tel: 0312-7528246，E-mail: shicp2006@126． com。* 通讯作者。
收稿日期 2011-01-18 修回日期
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2011-02-10
( 上接第 7页)
植物科学和未来技术的发展
许智宏1，2* ( 1．北京大学生命科学学院，北京 100871; 2．中国科学院上海植物生理生态研究所，上海 200032)
摘要 围绕全球粮食安全问题，就人类面对全球气候变化、农业可持续发展、能源和环境等问题的挑战，从植物科学和技术发展的现状及其
潜力出发，系统阐述了植物科学家在解决粮食安全等全球问题中能够担负的社会责任和应发挥的作用。并强调植物科学家应与农学家、生
态学家和环境专家携手，为发展低碳农业、培育高产优质抗性强新型农作物品种、开发新型能源植物、提供健康食品和药物、合理利用土地和
水资源、改善环境等方面提供新思路和新技术，为地球和人类的可持续发展作出贡献。
关键词 植物科学;粮食安全; 生物技术; 转基因;药用植物;能源植物
作者简介 许智宏( 1942 － ) ，男，江苏无锡人，教授，博士生导师，中国科学院院士，从事植物发育生物学、植物细胞培养及植物生物工程研究。* 通
讯作者。
收稿日期 2010-09-20 修回日期 2010-12-25
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