Aneuploidy and Karyotypic Polymorphism of Lysimachia

Aneuploidy and Karyotypic Polymorphism of Lysimachia mauritiana (Primulaceae) Distributed in Middle and Southern Parts in the Ryukyu Archipelago Belonging to Okinawa Prefecture, Japan

Yoshiko Kono1,2, Yoshikazu Hoshi3,*, Hiroaki Setoguchi4, Masatsugu Yokota5 and Kazuo Oginuma6

1 Graduate School of Human Health Science, Kochi Women’s University, 5-15 Eikokuji-cho, Kochi 780-8515, Japan 2 Herbarium (HAST), Biodiversity Research Center, Academia Sinica, Taipei 115, Taiwan 3 Department of Plant Science, School of Agriculture, Tokai University, Kawayou, Minamiaso-mura, Aso-gun, Kumamoto 869-1404, Japan 4 Graduate School of Human and Environmental Studies, Kyoto University, Yoshidanihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan 5 Laboratory of Ecology and Systematics , Faculty of Science, University of Ryukyus, 1 Senbaru, Nishihara-cho, Nakagami-gun, Okinawa 903-0213, Japan 6 Department of Biology, Faculty of Human Life and Environmental Science, Kochi Women’s University, 5-15 Eikokuji-cho, Kochi 780-8515, Japan

Received October 8, 2009; accepted November 16, 2009

Summary Aneuploidy and karyotypic polymorphism in 98 individuals of Lysimachia mauritiana collected in middle and southern parts of the Ryukyu Archipelago, Okinawa Pref., were cytologically analyzed. Aneuploids of 2nϭ16, 17, 18, 19 and 20, and 13 cytotypes were recognized in the areas. By using longer metacentric chromosomes as markers, the number of all cytotypes in the Ryukyu Archipelago, Japan was 18, together with data reported earlier.

Key words Aneuploid, Chromosomal polymorphism, Karyotypic variation, Lysimachia mauritiana, Ryukyu Archipelago.

The biennial plant, Lysimachia mauritiana L. (Primulaceae), distributed widely in the temperate and subtropical regions of both hemispheres grows on coastal rocks and seashores from north to south in the Japanese Archipelago (Iwatsuki et al. 1996). The chromosome numbers of the species has been reported to be 2nϭ20 or nϭ10 by using plant materials native to Korea, Japan and Taiwan in East Asia, and Hawaii (Kono et al. 2008). According to the karyotype with 2nϭ20, 2 different karyotypes have been reported as 2nϭ20ϭ4mϩ2smϩ4stϩ10t collected in the Shikoku District of Japan (Jinno 1956, Tanaka and Hizume 1978), and as 2nϭ20ϭ4mϩ4smϩ2stϩ10t collected in the Orchid Island of Taiwan (Oginuma et al. 2004b). Recently, the aneuploidy and karyotypic polymorphism of the species have been reported in Yonagunijima Island (Oginuma et al. 2004a) and northern and middle parts in the Ryukyu Archipelago belonging to Kagoshima Pref. (Kono et al. 2008). All plants collected in Yonagunijima Is. showed the chromosome number of 2nϭ16 with 3 cytotypes as 2nϭ16ϭ8mϩ2smϩ6t, 2nϭ 16ϭ7mϩ2smϩ1stϩ6t and 2nϭ16ϭ6mϩ2smϩ2stϩ6t. Meanwhile, 76 plants collected in northern and middle parts in the Ryukyu Archipelago showed the aneuploidy (2nϭ16, 17, 18, 19 and 20) with 16 cytotypes (Kono et al. 2008).

* Corresponding author, e-mail: [email protected]

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Figs. 1–5. Chromosome arrangement based on the karyotypic formula in Lysimachia mauritiana in Izenajima Is., Okinawajima Is., Iejima Is. and Gerumajima Is. 1. Shinzato (OMShi-0001; 2nϭ 20ϭ4mϩ4smϩ12t). 2. Geruma (GZG1-0001; 2nϭ20ϭ4mϩ2smϩ4stϩ10t). 3. Hedo (OKHe- 0001; 2nϭ20ϭ4mϩ2smϩ14t). 4. Uchihana (IzIzU-0111; 2nϭ19ϭ5mϩ3smϩ11t). 5. Higashieue (IeIeHiu1-0001; 2nϭ19ϭ4mϩ1mϩ2smϩ1stϩ11t). Five individuals were collected from Okinawajima Is. (1 and 3), Gerumajima Is. (2), Izenajima Is. (4) and Iejima Is. (5), respectively. Barϭ5 mm.

In the present paper, aneuploidy and karyotypic polymorphism in 98 individuals of Lysimachia mauritiana collected in middle and southern parts of the Ryukyu Archipelago, Okinawa Pref., were investigated.

Materials and methods Ninety-eight individuals of Lysimachia mauritiana collected from 23 sites in the Ryukyu Archipelago, Okinawa Pref., Japan were listed in Table 1 along with their karyotypic formula. They were cultivated in the greenhouse of Kochi Women’s University and their somatic chromosomes were examined on the basis of 3 good mitotic cells per individual using root tip. The methods for preparations and classiﬁcations of chromosome morphology followed Kono et al. (2008). As marker chromosomes, chromosomes of which the relative length was more than 5.4 were deﬁned as longer-median, longer-submedian and longer-subterminal centromeric chromosomes designated by the bold letters “m”, “sm” and “st” in respective karyotypic formula (see Tables 1 and 2). The chromosome number and the number of “m” were also used as markers to simplify the karytypic polymorphisms (Kono et al. 2008). The voucher specimens investigated were deposited in the herbarium of University of Ryukyus (RYU).

Results and discussion The aneuploidy of 2nϭ16, 17, 18, 19 and 20 and 16 cytotypes have been reported in northern and middle parts of the Ryukyu Archipelago belonging to Kagoshima Pref. (Kono et al. 2008). Comparing the present data with the foregoing data, the same aneuploidy of 2nϭ16, 17, 18, 19 and 20 was also recognized in middle and southern parts of the Ryukyu Archipelago belonging to

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Figs. 6–11. Chromosome arrangement based on the karyotypic formula in Lysimachia mauritiana in Izenajima Is., Okinawajima Is, Tokashikijima Is. and Shimojijima Is. 6. Irabusawada (SMISa- 0003; 2nϭ18ϭ6mϩ2smϩ10t). 7. Aharen (TTA2-0101; 2nϭ18ϭ5mϩ1mϩ2smϩ10t). 8. Ada (OKAd-0102; 2nϭ18ϭ4mϩ2mϩ2smϩ10t). 9. Uchihana (IzIzU-0110; 2nϭ17ϭ7mϩ2smϩ 8t). 10. Onna (ONS-0002; 2nϭ17ϭ6mϩ2smϩ1stϩ1stϩ7t). 11. Tokashiki (TTT1-0305; 2nϭ17ϭ5mϩ2mϩ2smϩ8t). Six individuals were collected from Shimojijima Is. (6), Tokashikijima Is. (7 and 11), Okinawajima Is. (8 and 10) and Izenajima Is. (9), respectively. Barϭ5 mm.

Figs. 12–13. Chromosome arrangement based on the karyotypic formula in Lysimachia mauritiana in Iheyajima Is. and Okinawajima Is. 12. Shimajiri (IhIhShi-0027; 2nϭ16ϭ8mϩ2smϩ6t). 13. Onna (ONS-0007; 2nϭ16ϭ6mϩ2smϩ2stϩ6t). Two individuals were collected from Iheyajima Is. (12) and Okinawajima Is. (13), respectively. Barϭ5 mm.

3_8.pdf 3 10.5.26 9:06:51 AM 6 Y. Kono et al. Cytologia 75(1) terminal ϭ subterminal chromosomes, t ϭ longer subterminal chromosomes, st distributed in the middle and southern parts of Okinawa Prefecture in the distributed in the middle and southern parts of Okinawa ϭ st Lysimachia mauritiana Lysimachia submedian chromosomes, ϭ Okinawa groupOkinawa groupOkinawa groupOkinawa groupOkinawa groupKerama Ada Is., Kunigami-son, Okinawajima Agunijima Is., Aguni-son, Hama Tonakisonichien Is., Tonaki-son, Tonakijima Shimajiri Is., Kumejima-cho, Kumejima Zamamijima Is., Zamami-son, Asa 0002, 0008, 0011, 0013 TTTo1-0001, OKAd-0101, 0102, 0103, 0104, 0105 KKShi-0101, 0102, 0106, 0109, 0111 AAHa1-0201, 0203, 0204, 0207, 0208 ZZAs1-0208, 0209, 0304, 0312, 0313 Miyako groupMiyako groupMiyako groupYaeyama groupYaeyama groupYaeyama groupYaeyama Hirarakarimata Is., Miyakojima-shi, Miyakojima Irabusawada Shimojijima Is., Miyakojima-shi, Ishigakijima Is., Ishigaki-shi, Nagura Kohama Is., Taketomi-cho, Kohamajima Kuroshima Is., Taketomi-cho, Kuroshima MMHKa-0001, 0002, 0005 Haimi Iriomotejima Is., Taketomi-cho, SMISa-0001, 0002, 0003 0006, 0007 KTKo-0002, IINa-0001, 0002, 0004, 0006, 0007 0002, 0003, 0006, 0008 KTKu1-0001, ITHa-0001, 0002, 0003, 0004, 0005 Okinawa groupOkinawa Ada Is., Kunigami-son, Okinawajima OKAd-0113 Okinawa groupOkinawa Izenajima Is., Izena-son, Uchihana IzIzU-0101, 0103, 0105, 0110, 0113 median chromosomes, sm Group name of Islands Locality number Individual ϭ 11t group Okinawa Iejima Is., Ie-son, Higashieue IeIeHiu1-0001 7t group Okinawa Is., Onna-son, Onna Okinawajima ONS-0002, 0012 ϩ ϩ 10t group Okinawa Is., Motobu-cho, Sesoko Sesokojima SMSe-0001, 0005, 0006, 0007, 0009 10t group Kerama Aharen Is., Tokashiki-son, Tokashikijima TTA2-0101 1st 8t group Kerama Tokashiki Is., Tokashiki-son, Tokashikijima TTT1-0305 1st 6t group Okinawa Is., Onna-son, Onna Okinawajima ONS-0003, 0004, 0005, 0006, 0007 10t group Kerama Gerumajima Is., Zamami-son, Geruma GZG1-0001, 0002, 0004, 0005, 0008 ϩ ϩ ϩ ϩ ϩ ϩ ϩ st 10t group Okinawa Dana Is., Iheya-son, Iheyajima IhIhDa2-0001, 0004, 0010, 0013, 0024 2st 11t group Okinawa Izenajima Is., Izena-son, Uchihana IzIzU-0111, 0201 6t group Okinawa Shimajiri Is., Iheya-cho, Iheyajima IhIhShi-0027 14t group Okinawa Hedo Is., Kunigami-son, Okinawajima OKHe-0001, 0002, 0003, 0004, 0005 1 4st 8t group Okinawa Dana Is., Iheya-son, Iheyajima IhIhDa2-0003, 0005, 0008, 0009, 0011 12t group Okinawa Is., Motobu-cho, Shinzato Okinawajima OMShi-0001, 0002, 0003, 0004, 0005 2sm 2sm 2sm 2sm 1) ϩ ϩ ϩ ϩ ϩ ϩ ϩ ϩ ϩ ϩ ϩ ϩ ϩ 2m 1m 1m 2sm 2sm 3sm 2sm 2sm 2m 2sm 2sm 2sm 4sm ϩ ϩ ϩ ϩ ϩ ϩ ϩ ϩ ϩ ϩ ϩ ϩ ϩ Chromosome numbers, karyotypes and their collection data of Ryukyu Archipelago, Japan Ryukyu m m m m m m m m m m m m m 5 4 6 4 5 6 8 5 4 6 4 7 4 Karyotype ϭ ϭ ϭ ϭ ϭ ϭ ϭ ϭ ϭ ϭ ϭ ϭ ϭ 18 18 18 19 16 19 16 20 17 17 20 17 20 longer median chromosomes, m ϭ ϭ ϭ ϭ ϭ ϭ ϭ ϭ ϭ ϭ ϭ ϭ ϭ ϭ n n n n n n n n n n n n n 2 2 2 2 2 2 2 2 2 2 2 2 Table 1. 2 m chromosomes. 1)

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Table 2. Summary of chromosome numbers and all Okinawa Pref. cytotypes of Lysimachia mauritiana distributed Thirteen cytotypes recognized in the in the Ryukyu Archipelago, Japan, together with data reported earlier Ryukyu Archipelago of Okinawa Pref. are shown in Table 1 and Figs. 1–13, however, the Chromosome Cytotype1,2) number of cytotypes studied here was less than number the 16 cytotypes reported earlier in the Ryukyu 2nϭ20 2nϭ20ϭ5mϩ2smϩ1stϩ12t Archipelago belonging to Kagoshima Pref., 2nϭ20ϭ4mϩ4smϩ12t i.e., 5 cytotypes with 2nϭ20 (5m), 2nϭ19 2nϭ20ϭ4mϩ2smϩ4stϩ10t (6m), 2nϭ17 (4m), 2nϭ16 (7m) and 2nϭ16 2nϭ20ϭ4mϩ2smϩ14t ϭ ϭ ϭ ϩ ϩ (5m) did not occur (see Kono et al. 2008), 2n 19 2n 19 6m 2st 11t ϭ ϭ 2nϭ19ϭ5mϩ3smϩ11t while 2 kinds of new cytotypes with 2n 20 2nϭ19ϭ4mϩ1mϩ2smϩ1stϩ11t 4mϩ2smϩ14t and 2nϭ19 (4m) were found in 2nϭ18 2nϭ18ϭ6mϩ2smϩ10t this study (Table 1, Figs. 3 and 5). In addition ϭ ϭ ϩ ϩ ϩ 2n 18 5m 1m 2sm 10t to 1 cytotype with 2nϭ16ϭ7mϩ2smϩ1stϩ6t 2nϭ18ϭ4mϩ2mϩ2smϩ10t 2nϭ17 2nϭ17ϭ7mϩ2smϩ8t reported earlier in Yonagunijima Is. (Oginuma 2nϭ17ϭ6mϩ1mϩ1smϩ1stϩ8t et al. 2004a), where located in southern part of 2nϭ17ϭ5mϩ2mϩ2smϩ8t the Ryukyu Archipelago in Japan, a total of ϭ ϭ ϩ ϩ ϩ ϩ 2n 17 4m 1m 2sm 2st 8t cytotypes occurred in middle and southern 2nϭ16 2nϭ16ϭ8mϩ2smϩ6t 2nϭ16ϭ7mϩ2smϩ1stϩ6t parts of the Ryukyu Archipelago of Okinawa 2nϭ16ϭ6mϩ2mϩ2smϩ6t Pref. 2nϭ16ϭ5mϩ2smϩ3stϩ6t Overall, it was clear that 18 cytotypes

1) ϭ ϭ occurred in the Ryukyu Archipelago, Japan m longer median chromosomes, m median chromo- ϭ somes, smϭlonger submedian chromosomes, smϭsub- (Table 2) including all cytotypes with 2n 20, median chromosomes, stϭlonger subterminal chromo- since it is possible that cytotypes with 2nϭ20 somes, stϭsubterminal chromosomes, tϭterminal have the original of the karyotypic polymor- chromosomes. 2) phism in this species. Among cytotypes with One of representative karyoypes was listed in res- ϭ pective cytotypes except 2nϭ20. 2n 20, having 4 longer-median chromosomes (m) are consistent, though their detailed karyotypes are different such as 2nϭ20ϭ 4mϩ4smϩ12t, 2nϭ20ϭ4mϩ2smϩ4stϩ10t and 2nϭ20ϭ4mϩ2smϩ14t reported in this study. When 3 cytotypes of 2nϭ20 (4m) were recognized as 1 cytotype, the total number of cytotypes was decreased to 16 grown in the Ryukyu Archipelago, Japan. Among those with 2nϭ20 (4m), 2nϭ20ϭ4mϩ2smϩ4stϩ10t was widely distributed in the main Japanese islands, northern parts of the Ryukyu Archipelago (Kono et al. 2008) and was also common to northern parts of Taiwan (Kono, unpublished data). In this study, however, individuals with the same karyotype of 2nϭ20ϭ4mϩ2smϩ4stϩ10t occurred in only Gerumajima Island located in the Kerama Group, west of Okinawajima Island, an area far from the main Japanese islands and Taiwan. Then, it is clear that individuals with 2nϭ20ϭ4mϩ4smϩ12t were found only in the Amami Group (Kono et al. 2008) and Okinawajima Island, and those with 2nϭ20ϭ4mϩ2smϩ14t were found exclusively in Cape Hedo, Kunigami-son, located in the northernmost of Okinawajima Island, mixed with plants of 2nϭ18 (6m) in this study. The rest of cytotype with 2nϭ20ϭ4mϩ4smϩ2stϩ10t was reported earlier on Orchid Island, southern part of Taiwan (Oginuma et al. 2004b). Individuals with the same karyotype of 2nϭ20ϭ4mϩ4smϩ2stϩ10t were also found in Maui Island, Hawaii (Kono, unpublished data). Further cytological studies of meiosis and FISH of telomere are needed to clarify the origin of karyotypic polymorphism and aneuploidy in this species.

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References

Iwatsuki, K., Yamazaki, T., Boufford, D. E. and Ohba, H. (eds.). 1996. Flora of Japan. Vol. IIIa. Kodansha, Tokyo. p. 482. Jinno, T. 1956. The chromosomes of Lysimachia. Jpn. J. Genet. 31: 87–88. Kono, Y., Hoshi, Y., Setoguchi, H., Yokota, M. and Oginuma, K. 2008. Aneuploidy and karyotypic polymorphism of Lysimachia mauritiana (Primulaceae) distributed in northern and middle parts in the Ryukyu Archipelago belonging to Kagoshima Prefecture, Japan. Chromosome Botany 3: 89–93. Oginuma, K., Hamada, A., Sato, H., Kono, Y., Yokota, M. and Setoguchi, H. 2004a. Aneuploidy and karyotypic variation of Lysimachia mauritiana (Primulaceae) in the Yonagunijima Island, the Ryukyu Archipelago, Japan. Chromosome Sci. 8: 45–54. —, Sato, H., Kono, Y., Yokota, M., Setoguchi, H. and Kokubugata, G. 2004b. Karyomorphology of Lysimachia mauritiana (Primulaceae) in the Orchid Island, Taiwan. Chromosome Sci. 8: 63–66. Tanaka, A. and Hizume, M. 1978. Karyomorphological studies on species differentiation in some species of Lysimachia.La Kromosomo II-11-12: 301–312.

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