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標題: 臺灣錦葵科植物染色體之研究
Chromosome Study of the Malvaceae in Taiwan
作者: 鄭雅芳
Cheng, Yea Fang
關鍵字: Malvaceae;錦葵科;chromosome;karyotype analysis;染色體;核型分析
出版社: 植物學系
摘 要 全世界的錦葵科植物約有 110 屬 2300 種,主要分布於熱
帶﹑亞熱帶及溫帶地區。臺灣原生之本科植物共計 8 屬 23 種 2 亞種 2
),已馴化者有 2 屬 3 種,其中有 6 種的染色體曾被研究過。 本論文
即利用臺灣原生及已馴化之錦葵科植物為材料,共研究了 7屬 15 種 1
亞種及 1 變種。 使用醋酸洋紅壓碎法製片,觀察根尖細胞有絲分裂中期
之染色體,並進行核型分析。 大部份學者認同本科主要的染色體原始
基數為 x=7, 見於莔麻屬﹑金午時花屬﹑繖楊屬及野棉花屬。賽葵屬染
色體基數為 x=12,木槿屬較複雜為 x=11-20。在染色體數目上野棉花屬
的野棉花 2n=28,梵天花 2n=28 為多倍體起源之二倍體,即古多倍體;
木槿屬的木芙蓉 2n=92,山芙蓉 2n=92, 黃槿 2n=96,皆為基數 x=16
之六倍體,但前兩者缺失 4 條染色體成為非整倍體; 繖楊之染色體數目
為 2n=26,可能是非整倍數之二倍體。 另外,香葵的染色體數為 2n=6
x=72,賽葵為 2n=2x=24,金午時花屬中除了細葉金午時花﹑圓葉金午時
花為 2n=4x=28, 薄葉金午時花﹑澎湖金午時花為2n=4x=32 之外,其
餘 4 種均為 2n=2x=14。本科植物中,染色體最小的為黃槿 0.53μ m,
最大的則是繖楊 4.61 μ m; B 染色體僅存在於金午時花一種,而隨體則
出現在山芙蓉(第 12 對)﹑薄葉金午時花(第 8 對)及野棉花(第 6
對)之短臂上,分別屬於 a 型﹑ b 型及 c 型隨體。 以核型來看,
錦葵科植物染色體有 86.0% 為兩臂對稱的 M ﹑ m 及 sm 型染色體,此
意示著本科為演化歷史上較古老或原始的植物。 由核型分析可知,金午
時花屬為最原始,賽葵屬為最特化之植物。 在金午時花屬中以擬金午時
花較原始,而薄葉金午時花及澎湖金午時花為最進步之種類。 木槿族的
繖楊屬為較原始的類群,其外部形態特徵, 染色體特徵﹑數目及核型組

ABSTRACT The family Malvaceae approximately consists of
2300 species groupedinto 110 genera in the world and
mostly distributed in the tropical,subtropical and temperate
regions. There are 23 species, 2 subspecies and 2varieties
belonging to 8 genera, indigenous to Taiwan. Among these
species,Sida parvifolia and S. uniaristata are new species and
S. rhomboidea newlyrecorded one in this study), In addition,
there are 3 species in 2 generanaturalized in Taiwan. Six
species of those plants have been investigatedcytologically in
previous reports. The materials of 15 species 1 subspeciesand 1
variety of 7 genera were collected throughout Taiwan Island
andstudied for chromosome characteristics of somatic
cells, usingaceto-carmine squash technique. The basic number
of chromosomes in the genera Abutilon, Sida, Thespesiaand Urena
have been reported as x=7 and considered to be primitive by
themost previous papers. Whereas, that of the genus
Malvastrum (x=12) andHibiscus (x=11-20) are derived. The
chromosome numbers of both species ofUrena lobata and U.
procumbens are 2n=28. They are the present diploid andthe
paleopolyploid derived from the ancestor by poly-ploidization.
Threespecies of the genus Hibiscus, i.e. H. mutabilis (2n=92),
H. taiwanensis(2n=92) and H. tiliaceus (2n=96), are hexaploid
based on x=16. However theformer two species are aneuploid
evolved by losing four chromosomes. Thechromosome number of
Thespesia populnea is 2n=26 and is considered as adiploid.
Moreover, the chromosome numbers of Abelmoschus moschatus
is2n=6x=72, Malvastrum coro-mandelianum 2n=2x=24, Sida
acuta and S.cordifolia 2n=4x=28, S. mysorensis and S.
veronicarfolia 2n=4x=32, and theother 4 species of Sida 2n=2
x=14. In these plants of the family, thesmallest typ e of
chromosomes (0.53 μ m) is found in Hibiscus tiliaceusand the
biggest one (4.61 μ m ) in Thespesia populnea. B chromosomes
areonly found in Sida rhombifolia. ssp. rhombifolia
Satellites are found atthe short arm of chromosome in Hibiscus
taiwanensis (the 12th pair ofchromosomes), Sida mysorensis
(the 8th pair) and Urena lobata (the 6thpair) and are
considered as a, b and c types, respectively. Based on the
karyotype characteristics, 86% of the chromosomes
areassigned as M, m and sm types, which is considered showing
more or lesssymmetrical for the two arms of the chromosomes,
primitive of this family.The karyotypes of Sida are most
primitive and Malvastrum are most derived.Among the genus
Sida, S. rhomboidea is the most primitive, both S.
mysorensis and S. veronicaefolia are most derived species.
In the tribeHibisceae, Thespesia is the most primitive genus.
Its morphological andchromosomal characteristics, chromosome
number and the karyotype componentsare different from the
other genera of this tribe. Therefore, it isappropriate to
be separated from that tribe and treated as the
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