Chromosome Science 14: 53-62, 2011 Okuno et al. 53 Regular Article Stable chromosome number in horticultural cultivars of Farfugium japonicum (Asteraceae), with descriptions of their morphological characteristics Hajime Okuno, Masashi Nakata and Masahiro Mii Received: January 9, 2011 / Accepted: December 19, 2011 © 2011 by the Society of Chromosome Research Abstract Introduction A total of 111 horticultural cultivars of Farfugium ja- Farfugium japonicum (L.) Kitam. (Asteraceae), Japanese ponicum were studied cytologically and described mor- name: ‘Tsuwabuki’, is a perennial herb native to Japan, phologically for the first time. All 111 cultivars with South Korea, Taiwan and the middle part of China various unusual morphologies, such as dwarf, rumpled (Kitamura 1981). In Japan it grows on rocky coastal cliffs in leaves, etc., had 2n=60 chromosomes, which was the Honshu (southwestern part), Shikoku, Kyushu, Ryukyu and same number as in wild plants. Only one individual ob- Ogasawara Islands (Horikawa 1972, Koyama 1995). Wild tained by tissue culture of the cultivar ‘Yukibeni-botan’ plants of F. japonicum have been used as a garden plant had exceptional chromosome number with 2n=59. In since the Edo period (Kaibara 1694), and some cultivars 14 cultivars with 2n=60 chromosomes examined, no ab- showing morphological variations or variegation in leaves normal chromosome behavior was observed through have been described in the literatures published more than the microsporogenesis, and at the meiotic metaphase 180 years ago (Iwasaki 1828, Mizuno 1829). After that, I, 30 bivalents were observed. Among the flowered 96 these variants have been preserved mainly by collectors. individuals in 95 cultivars, seven individuals had no pol- The number of cultivars has gradually increased and 73 len grains, and those having atrophied head, such as variants were listed in “Hana-ninki” (2001). Now more “SHISHI” and “KURUMA”, showed relatively low pollen than one hundred cultivars are known (Okuno et al. 2007). stainabilities, 48.3 and 23.4% in average, respectively, Chromosome numbers of wild F. japonicum have whereas the other cultivars had high stainability (91.3% been reported to be n=30 (Ishikawa 1916, as Ligularia in average). The 2n=59 somaclonal variant of the cultivar tussilaginea) and 2n=60 for the plants from Japan (Arano ‘Yukibeni-botan’ showed the lowest stainability (0.3%). 1962, Miyagi 1971, Okuno et al. 2005), Taiwan (Hsu These results indicate that horticultural cultivars of F. ja- 1970) and China (Su and Liu 1995, Liu 2001). Recently we ponicum are stable diploids from the cytogenetical view- examined chromosome number for 190 individuals of wild point, and that the morphological diversity in the culti- F. japonicum, including four taxonomic varieties, from 68 vars should not be ascribed to the numerical changes of localities in 31 prefectures of Japan and two localities in chromosomes but must have been caused by mutation Taiwan. The all individuals had the chromosome number of gene(s) responsible for morphogenesis. of 2n=2x=60 with high pollen stainability (93.9±8.8%) except for one spontaneous aneuploid (2n=61) (Okuno et al. 2009). However, no cytological studies have been Key words: Asteraceae, chromosome number, Farfugi- conducted yet on horticultural cultivars of this species. um japonicum, horticultural cultivar, pollen stainability Thus, in this paper, we describe the results of the studies on chromosome number and pollen fertility of 111 horticultural cultivars in F. japonicum with artificial classification and brief descriptions of the morphology of them. Hajime Okuno 3250-201 Fukaisawa-machi, Naka-ku, Sakai, Osaka 599-8236, Materials and Methods Japan Masashi Nakata (*) The cultivars of F. japonicum used in this study had Botanic Gardens of Toyama, 42 Kamikutsuwada, Fuchu-machi, been collected by the first author in the last 25 years from Toyama 939-2713, Japan nurseries or private collectors of the species throughout Tel: +81-76-466-4187, Fax: +81-76-465-5923 Japan. The 112 individuals of 111 horticultural cultivars e-mail: [email protected] as shown in Table 1 had been cultivated in pots at the Masahiro Mii first author’s private garden at least for five years under Laboratory of Plant Cell Technology, Graduate School of Horticul- continuous observations. Vouchers have been preserved at ture, Chiba University, 648 Matsudo, Matsudo, Chiba 271-8510, Ja- the Botanic Gardens of Toyama (TYM). pan For mitotic and meiotic chromosome observation, fresh 54 Chromosome number of horticultural cultivars of Farfugium japonicum Table 1. Characteristics, chromosome numbers, pollen stainabilities, and vouchers of the horticultural cultivars of Farfugium japonicum ex- amined. Chromo- some Pollen Cultivar Characteristics number stainability Voucher (2n) (%) Group Ⅰ . “SHISHI (BOTAN)” : Leaf blade rolled; margin crisped and waved. Head atrophied 1. ‘Midori-hime’ Leaf blade slightly rolled; margin rough crisped, low waved. Head at- 60 28.1 HO5084 rophied. 2. ‘Hira-jishi’ Leaf blade slightly (or no) rolled; margin rough crisped, medially 60 62.3 HO5023 waved. Head atrophied. 3. ‘Mai-jishi’ Leaf blade slightly rolled; margin rough crisped, highly waved. Head 60 44.7 HO5027 (Fig. 1-1) atrophied. 4. ‘Genkai-daruma-jishi’ Leaf blade slightly rolled; margin rough crisped, highly waved; peti- 60 78.1 HO5045 ole highly fasciated. Head atrophied. 5. ‘Sekka-botan-jishi’ Leaf blade medially rolled; margin rough crisped, highly waved; peti- 60 93.6 HO5015 ole highly fasciated. Head atrophied. 6. ‘Daruma-jishi’ Leaf blade medially rolled; margin rough crisped, highly waved; peti- 60 67.7 HO5014 (Fig. 1-2) ole extreamly fasciated. Head atrophied. 7. ‘Hotei-sama’ Leaf blade medially rolled; margin medially crisped, highly waved; 60 34.8 HO5049 petiole short, etreamly fasciated. Head atrophied. 8. ‘Kumano-jishi’ Leaf blade slightly rolled; upper surface bearing leaf-like prominence; 60 not flowered HO5086 margin medially crisped, low waved. 9. ‘Uzushio’ Leaf blade slightly rolled; margin medially crisped, medially waved. 60 54.0 HO5001 Head atrophied. 10. ‘Shirahama-jishi’ Leaf blade slightly rolled; margin medially crisped, highly waved. 60 48.6 HO5016 Head atrophied. 11. ‘Genkotsu’ Leaf blade medially rolled; margin medially crisped, highly waved; 60 13.4 HO5051 petiole highly fasciated. Head atrophied. 12. ‘Yukibeni-botan’ Leaf blade slightly rolled; margin fine crisped, medially waved. Head 60 46.1 HO5029 atrophied. 59 0.3 HO5024 13. ‘Satsuma-botan’ Leaf blade slightly rolled; margin fine crisped, medially waved. Head 60 7.7 HO5012 atrophied. 14. ‘Yukibeni-henge’ Leaf blade slightly rolled; margin fine crisped, medially waved; peti- 60 no pollen HO5064 ole subbranched. Head atrophied. 15. ‘Unryu-jishi’ Leaf blade slightly rolled, recurved; margin fine crisped, medially 60 no pollen HO5071 waved; petiole subbranched. Head atrophied. 16. ‘Kirin-ju’ Leaf blade slightly rolled; margin fine crisped, highly waved; petiole 60 no pollen HO5006 subbranched. Head atrophied. Group Ⅱ . “KURUMA (FUGIRE)”: Leaf blade incised 17. ‘Fukuju-botan’ Leaf blade medially rolled, medially and fine incised; lower surface 60, 30 II 23.4 HO5040 (Fig. 1-3)" bearing hook-like prominence; margin highly waved. Head atro- phied. 18. ‘Temari’ Leaf blade medially rolled, deeply and fine incised; lower surface 60 no pollen HO5041 bearing hook-like prominence; margin highly waved. Head atro- phied. Group Ⅲ .“NOKOGIRI (TSUNO-DASHI)”: Leaf margin dentate 19. ‘Ryukaku’ Leaf margin low- and rough dentate, slightly waved; petiole short, 60 93.4 HO5063 (Fig. 1-4) fasciated. 20. ‘Hakkaku-uryu’ Leaf margin rough dentate; lower surface bearing hook-like promi- 60 93.3 HO5077 (Fig. 1-5) nence. 21. ‘Ura-no-mai’ Leaf margin low- and rough dentate, low waved; blade slightly rolled; 60 92.2 HO5067 petiole short, fasciated. 22. ‘Oya-jishi’ Leaf margin low- and densely dentate, low waved; blade slightly 60 97.9 HO5002 rolled; petiole short, fasciated. 23. ‘Hime-daruma’ Leaf margin densely dentate, low waved; blade slightly rolled; petiole 60 93.3 HO5022 short, fasciated. 24. ‘Sakae-jishi’ Leaf margin medially dentate, slightly waved; blade slightly rolled; 60 97.3 HO5011 petiole short, fasciated. 25. ‘Ryujin’ Leaf margin medially dentate, medially waved; blade slightly rolled; 60, 30 II 95.8 HO5034 petiole short, fasciated. 26. ‘Genkai-jishi’ Leaf margin densely dentate, low waved; blade slightly rolled; petiole 60 97.2 HO5048 short, fasciated. 27. ‘Kushira-jishi’ Leaf margin densely dentate, medially waved; blade slightly rolled; 60 95.4 HO5007 petiole short, fasciated. 28. ‘Fuku-manryo’ Leaf margin densely dentate, highly waved; blade rolled; petiole 60 98.7 HO5025 short, highly fasciated. 29. ‘Hishakaku’ Leaf margin large- and rough dentate, highly waved; blade outward- 60 not flowered HO5020 bended at the margin. Okuno et al. 55 Table 1. (continued) Chromo- some Pollen Cultivar Characteristics number stainability Voucher (2n) (%) 30. ‘Ryuho’ Leaf margin large- and rough dentate, slightly waved; blade 60 92.7 HO5069 (Fig. 1-6) slightly rolled; petiole short, fasciated. 31. ‘Hime-shinryu’ Leaf margin large- and rough dentate, low waved; blade slightly 60 93.7 HO5021 rolled; petiole short, fasciated. 32. ‘Keikan’ Leaf margin large- and rough dentate, medially waved; blade 60, 30 II 99.2 HO5008 (Fig. 1-7) slightly rolled; petiole short, fasciated. 33. ‘Fuku-daruma’ Leaf margin large- and rough dentate, highly waved; blade slight- 60 95.5 HO5073 ly rolled; petiole short, fasciated. 34. ‘Kyoshiba’