Cytological Studies of Seven Taxa of Cyperaceae Collected from the Bonin (Ogasawara) Islands

2006·0.44 MB·English

by  Okihito Y Ano

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Cytological Studies of Seven Taxa of Cyperaceae Collected
from the Bonin (Ogasawara) Islands
a a
Okihito YANO，T eruo KATSUYAMAb and Tak吋iHOSHINO
aDepartment of Mathematical and Environmental System Science，G raduate School of Informatics，
Okayama University of Science，1- 1，Ri dai-cho，O kayama，70 0-0005 JAPAN;
E-mail: [email protected]
bKanagawa Prefectural Museum of Natural History，4 99，Ir yuda，O dawara，2 50-0031 JAPAN
(Received on August 5，2 005)
Seven taxa of Cyperaceae collected from the Bonin Islands were used for
karyomorphological studies. Chromosome numbers are reported for Carex hattoriana
(2n =6 2)，C . toyoshimae (2n =6 2)，F imbristylis longispica var. boninensis (2n =3 0)，F .
longispica var. hahajimensis (2n =3 0)，R hynchospora chinensis var. curvoaristata (2n =
36) and R. boninensis (2n =2 0) for the first time. These six taxa are endemic to the Bonin
Islands. Our finding of 2n =8 2 for Actinoscirpus grossus differs from that of ap revious
study. The chromosome number of R. chinensis var. chinensis was previously reported as
2n =6 2，a nd our results suggest that this number might have arisen by chromosome
duplication of 2n =3 6 in R. chinensis var. curvoaristata.
Key words: Bonin Islands，c hromosome number，C yperaceae，d iffuse centromeric chro-
mosome，e ndemic species.
The Bonin Islands are typical oceanic is- oceanic islands. However. there has been no
lands，a nd are located 1，000 km south of report on cytological study of Cyperaceae in
Tokyo，J ap an，i n the westem Pacific Ocean the Bonin Islands. The purpose of this paper
(lto 1998). Many vascular plants endemic to is to report the Chr01TIOSOme numbers of
the Islands have been reported (Ono et al. seven taxa of Cyperaceae from the Bonin
1986)， including those from the family Islands，a nd to clarify the cytological rela-
Cyperaceae. Cyperaceae includes over 5000 tionships of allied species.
species (Goetghebeur 1998). Thirty-four spe-
cies of Cyperaceae have been reported for Materials and時lethods
the Bonin Island，o f which six species are Seven taxa of Cyperaceae collected from
endemic to the islands (Toyoda 2003). the Bonin Islands were used for karyo-
Koyama (1990) reported sixty-nine species morphological observations. The materials
of Cyperaceae in the Hawaiian Islands，o f examined訂elisted in Table 1，o f which the
which seventeen species are endemic. The following six taxa are reported to be endemic
level of endemism of Cyperaceae in the to the Bonin Islands: Carex hattoriαna，C .
Bonin Islands is almost same as in the toyoshimae， Fimbristylis longispica var.
Hawaiian Islands. Cytological studies of the boninensis，F. longispica var. hahαyimensis，
endemic species of Cyperaceae in the Bonin Rhynchospora chinensis var. curvoaristata
Islands are important for understanding the and R. boninensis (Toyoda 2003). Somatic
evolution and diversification of this family in chromosomes were observed in the meriste-
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100 植物研究雑誌第81巻第2号 平成18年4月
matic cells of root tips. The root tips were may be an intraspecific aneuploid，w hich is
preeatedin 0.002 M 8-hydroxyquinoline common in Cyperaceae plants with diffuse
仕
solution for 1h a t 230C and 15 ha t 40C. centromeric chromosomes (Goetghebeur
They were fixed in acetic alcohol (1 :3) for 1998).
over 16 h at -20oC or for 1.5h at 230C， Carex hattorianαhad the chromosome
stained by Feulgen' sn uclear reaction，m ac- number of 2n = 62，a nd the somatic meta-
erated in am ixture of 2% pectinase and 2% phase chromosomes were less than 0.8μmin
cellulase for 1h a t 370C，r estained in 1% length (Fig. lB). Carex hattoriαna belongs
aceto-orcein and squashed. Voucher speci- to section Graciles，a nd is closely related to
mens were deposited in the Herbaria of C. brunnea (Ohwi 1936). The chromosome
Kanagawa Prefectural Museum of Na tural number of C. brunnea was reported as 2n =
History (KPM) and Okayama University of 62 by Tanaka (1948). Our results support the
Science (OKAY ). close relationship between these two species.
Cαrex toyoshimae had the chromosome
Results and Discussion number of 2n = 62，a nd the somatic meta-
The chromosome numbers determined in phase chromosomes were less than 0.8μmin
this study are shown in Table 1. Primary length (Fig. lC).
constriction was not observed in any species. Fimbristylis longispica var. boninensis
Actinoscirpus grossus had the chromo- had the chromosome number of 2n = 30. The
some number of 2n = 82，a nd all somatic somatic metaphase chromosomes ranged
metaphase chromosomes were less than 0.8 from 1.2 to 2.2μm in length (Fig. lD).
μm in length (Fig. lA). Actinoscirpus Fimbrisηlis longispica var. hahajimensis
grossus collected from lndia was reported as also had 2n = 30. The somatic metaphase
2n =ca . 88 by Rath and Patnaik (1978). The chromosomes ranged from 1.2 to 2.1μm in
2n = 82 of A. grossus from the Bonin Islands length (Fig. lE). Morphologically，th ese two
Table 1. Taxa，l ocality and voucher，a nd chromosome numbers of seven taxa of Cyperaceae collected from the
Bonin Islands
Taxa Locality and Vo ucher Chromosome number (2n)
Actinoscirpus grossus (L. f.) Goetghebeur & D. A. Simpson
Hahaオima，Pond Hasu; Katsuyama & al. 19915 (OKAY) 82
Carex hattoriana Nakai
Hahaサima，Mt. Tibusa; Katsuyama & a .l19913 (OKAY) 62
C. toyoshimae Tuyama
Haha-jima，M t. Kuwanoki; Katsuyama & al. 19917 (OKAY ) 62
Hahaオima，Sekimon; Katsuyama & al. 19918 (OKAY) 62
Fimbrisηlis longispica Steud. var. boninensis (Hayata) Ohwi
Hahaサima，Mt. Tibusa; Katsuyama & al. 19911 (OKAY) 30
Chichi-jima，K ominato; Katsuyama & al. 19920 (OKAY) 30
F. longispica Steud. var. hahajimensis (Tuyama) Ohwi
Haha-jima，M t. Kensaki; Katsuyama & al. 19910 (OKAY) 30
Haha-jima，M t. Cyouki; Katsuyama & al. 19914 (OKAY ) 30
Rhynchospora boninensis Nakai ex Tuyama
Chichiオima，Higashi-daira; Katsuyama & al. 19872 (OKAY ) 20
R. chinensis Nees & Meyen var. curvoaristata (Tuyama) Ohwi
Chichi-jima，H igashi-daira; Katsuyama & al. 19871 (OKAY) 36
Apri12006 Journal of Japanese Botany Vo .l81 No. 2 101
varieties were mainly separated by the width curvoaristata (2n = 36) and R. boninensis
of their leaves; 4-5 mm in Fimbristylis (2n =2 0)，w ere determined for the first time
longispica v boninensis and 1-1.5 mmi n in this study. Two endemic species to the
紅 .
F. longispica var. hahajimensis. There were Bonin Islands， C. hattoriana and R.
no karyomorphological differences between boninensis had the same chromosome num-
these two varieties. ber as their morphologically closely related
Rhynchospora chinensis v curvoaristata species. Rhynchospora chinensis var. curvo-
紅 .
had 2n = 36. The somatic metaphase chro- aristata is closely related to R. chinensis var.
mosomes ranged from 0.6 to 1.1μm in chinensis and chromosome duplication was
length (Fig. lF). The chromosome number of found between these two taxa.
R. chinensis var. chinensis was reported as
2n = 62 by Tanaka (1948) and Hoshino The authors thank to Chikako Hasekura，
(1987). Hoshino (1987) reported that R. Hiroko Nakayama， Tetsuo Ohmori， and
chinensis var. chinensis collected from Takaya Yasui for their great help in collect-
Okayama Pref.，J apan was 2n =6 2，a nd that ing plant materials.
the metaphase chromosomes ranged from 0.8
to 1.9μm in length. In Carex，w hen the chro- References
mosome number increases by aneuploidy， Devies E. W. 1956. Cytology，ev olution and origin 9f
both the lengths and widths of all chromo- the aneuploid series in the genus Carex. Hereditas
42: 349-365.
somes tend to become smaller (Hoshino
Goetghebeur P. 1998. Cyperaceae. In: Kubitzki K.
1981). The aneuploidy of Carex was re-
(ed.)，T he Families and Genera of Vascular Plants
ported as agmatoploidy (chromosome frag-
4. Flowering Plants，M onocotyledons: Alismatanae
mentation) (Devies 1956). In our study，t he and Commelinanae (except Gramineae). pp. 141-
chromosome sizes of R. chinensis v紅. 190. Springer，Be rlin.
chinensis (2n = 62) and R. chinensis var. Hoshino T. 1981. Karyomorphological and cyto-
curvoaristata (2n =3 6) were found to be genetical studies on aneuploidy in Carex. J. Sci.
Hiroshima Univ. 17: 155-238.
almost equal. Our results suggest that the
1987.Karyomorphological studies on seven spe-
一一一
2n = 62 of R. chinensis var. chinensis might cies of Japanese Rhynchospora (Cyperaceae). La
have arisen by chromosome duplication，a nd Kromosomo 11 47-48: 1557-1561.
not agmatoploidy from a certain ancestor ItoM . 1998. Origin and evolution of endemic plants of
with smaller chromosome numbers such as Bonin (Ogasawara) Islands. Res. Popul. Ecol. 40:
205-212.
R. chinensis var. curvoaristata.
Koyama T. 1990. Cyperaceae. In: Wagner W. L.，
Rhynchospora boninensis had 2n =2 0.
Herbst D. R. and Sohmer S. H. (edsよManualof
The somatic metaphase chromosomes ranged the Flowaring Plants of Hawaii Vol. 2. pp.1381-
from 1.1t o 1.8μmi n length (Fig. 1G) . Ohwi 1436. Univercity of Hawaii Press & Bishop
(1943) reported that R. boninensis is closely Museum Press，H onolulu.
Ohwi J. 1936. Cyperaceae Japonicae. .1As ynopsis of
related to R. rubra，s haring ag lobul termi-
紅 the Caricoideae of Japan，i ncluding the Kuriles，
nal capitulum. The chromosome number of
Saghalien，K orea and Formosa. Mem. Coll. Sci.
R. rubra was reported as 2n =2 0 by Hoshino Kyoto Imp. Univ. Ser. BB iol. 11: 464-471.
(1987). Our results also support ac lose rela- 一一一 1943.Cyperaceae Japonicae. 11. A synopsis of
tionship between these two species. the Rhynchosporoideae and Sciropoideae of Jap an，
The chromosome numbers of Carex including the Kuriles， Saghalien， Korea and
Formosa. Mem. Coll. Sci. Kyoto Imp. Univ. Ser. B
hattoriana (2n = 62)，C . toyoshimae (2n =
Biol. 18: 15-17，80 .
62)，F imbristylis longispica var. boninensis
Ono M.，K obayashi S. and Kawakubo N. 1986. Present
(2n =3 0)，F . longispica v紅.hahajimensis situation of endangered plant species in the Bonin
(2n = 30)， Rhynchospora chinensis var. (Ogasawara) Islands. Ogasawara Res. 12: 1-32.
102 植物研究雑誌第81巻第2号 平成18年4月
Rath S. P. and Patnaik S. N. 1978. Cytological studies Tokyo (in Japanese).
in Cyperaceae -with special reference to its taxon- Toyoda T. 2003. F10ra of Bonin Islands，S econd
omy 11. Cytologia 43: 643-653. Edition. 522 pp. Aboc & CO.，Ltd.，K amakura (in
Tanaka N. 1948. The Problem of Aneuploidy. Japanese).
Biological Contribution in Japan 4. Hokuryukan，
矢野興ーヘ勝山輝男 ，星野卓二 .小笠原諸島産
b a
カヤツリグサ科植物7分類群の細胞学的研究
小笠原諸島より採集したカヤツリグサ科植物7 ca. 88 (Rath and Patnaik 1978) とは異なった染色
分類群について染色体数を報告した.このうち小 体数が観察された.小笠原固有のムニンイヌノハ
笠原諸島に固有の6分類群については今回が初め ナヒゲ (R.chinensis var. curvoaristata)は2n=3 6
ての報告である. ムニンナキリスゲ (Carex であるが，近縁種とされているイヌノハナヒゲゲ、
hattoriana) とセキモンスゲ(仁 toyoshimae) が (R. chi
仰
2n =6 2，ムニンテンツキ (Fimbristylislongispica 1円98幻7) と異なつていた.この二変種は，染色体の
var. boninensis)とハハジマテンツキ (F.longispica 大きさがほとんど同じであることから，イヌノハ
Vぽ.hahajimensis)が2n= 30，ムニンイヌノハナ ナヒゲでは染色体の重複による核型の分化がおこっ
ヒゲ (Rhynchosporachinensis v訂.curvoaristata) ていると考えられる.
が2n=3 6，シマイガクサ (R.boninensis)が2n= (a岡山理科大学大学院総合情報研究科
20であった. オオサンカクイ (Actinoscirpus 数理・環境システム専攻，
grossus)では 2n=82を観察し，従来の報告2n= 神奈川県立生命の星・地球博物館)
b