214 1. Introduction It is thought that ancestors of grape (genus Vitis) ap- peared during the first half of the Cretaceous period. They then spread around the world according to environmental and anthropogenic influences, and now comprise three ma- jor groups of species: European, North American, and East Asian species, which differ in their physiological and eco- logical characteristics (Horiuchi and Matsui, 1996). Wild grapes native to Japan belong to the group comprising the East Asian species. Only a few reports on wild grape spe- cies, including classification, physiological, and ecological characterizations, have been published so far (Horiuchi and Matsui, 1996). Nevertheless, the importance of wild grapes as genetic resource for grape breeding has gradually been recognized because some wild grapes show superior traits towards global warming in terms of sustainable berry pro- duction under hot and humid conditions. This paper describes the identification and classifica- tion of wild grapes native to Japan. Their physiological and ecological traits, as well as their utilization are also reviewed by focusing on the latest research findings re- garding wild grapes native to Japan. 2. Geographical distribution This, and previous studies, found that seven Vitis spe- cies and eight varieties are distributed throughout Japan, from Hokkaido (northern region) to Okinawa (southern region) (Table 1) (Nakagawa et al., 1991). Of these, Yam- abudo, Ebizuru, and Sankakuzuru are the three main spe- cies found in Japan. Many other species exist locally in limited areas. In addition, researchers from Osaka Pre- fecture University discovered Shiohitashibudou (tenta- tive name) (Nakagawa et al., 1991). The geographical distribution of the wild grapes native to Japan are shown in figures 1-4. These figures were created from a site survey from Hokkaido to Okinawa starting in 1973, and were made based on past records and reports using con- served (pressed) leaf specimens from Hokkaido Univer- sity, Tokyo Metropolitan University, Kyoto University, Niigata University, Kumamoto University (Japan), and Taiwan University (Taiwan). Yamabudou, Vitis coingnetiae Pulliat (Fig. 1) This species is widely distributed from level ground to the lowest mountain areas in Hokkaido; from the low- est areas in the mountains to the mountain zone in the Tohoku district (northeastern region of Japan); from the mountain zone to the alpine region in the Chubu district (central region of Japan); and in the alpine regions of the Kinki, Chugoku, and Shikoku districts. It is thought that this species is also present in a limited area of the alpine regions in the Kyushu district, but it has not yet been dis- covered around Mt. Aso, which is consistent with the fact that we could not find any pressed leaf specimen in the universities located in the Kyushu distinct. It is notewor- thy that this species is not distributed in South Korea, China, and neighboring countries; including Far Eastern Russia. However, it has been confirmed that Yamabudou grows naturally in the South Chishima and Sakhalin dis- tricts (Horikawa, 1972). Sankakuzuru (Gyojanomizu), V. flexuosa Thunb. (Fig. 2) This species is distributed in the mid regions of the Yamabudou (Fig. 1) and Ebizuru (Fig. 3) ranges, overlap- Wild grape germplasms in Japan H. Yamashita*, R. Mochioka** * Faculty of Life and Environmental Sciences, University of Yamanashi, 4-4-37, Takeda, Kofu, Yamanashi, Japan. ** Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, Kita, Kagawa, Japan. Key words: anthocyanins, breeding, classification, geographic distribution, growth cycle, Vitis. Abstract: In Japan, seven species and eight varieties of wild grapes were identified, among which the main species are Vi- tis coignetiae Pulliat, V. flexuosa Thunb., and V. ficifolia Bunge var. lobata (Regel) Nakai (syn. V. thunbergii Sieb. et Zucc.). This paper summarizes the identification and classification of wild grapes native to Japan based on the past reports. Their distributions in Japan and physiological and ecological traits are also reviewed for effective practical use for grape breeding in the future. Adv. Hort. Sci., 2014 28(4): 214-224 Received for publication 17 September 2014 Accepted for publication 14 November 2014 215 Table 1 - Systematic and geographical distribution of wild grapes native to Japan (Nakagawa et al., 1991) Species or varieties Japanese name Locality where grown Vitis coignetiae Pulliat Yamabudou Hokkaido, Honshu, Shikoku Vitis coignetiae Pulliat var. glabrescens Hara Takeshimayamabudou Hokkaido, Honshu Vitis flexuosa Thunb. Sankakuzuru (Gyojanomizu) Honshu, Shikoku, Kyusyu Vitis flexuosa Thunb. var. rufo-tomentosa Makino Kesankakuzuru Southern Honshu, Shikoku Vitis flexuosa Thunb. var. tsukubana Makino Usugesankakuzuru Northern Honshu Vitis flexuosa Thunb. var. crassifolia Hara Atsubasankakuzuru Shikoku Vitis saccharifera Makino Amazuru (Otokobudou) Southern Honshu, Shikoku Vitis yokogurana Makino Yokogurabudou Shikoku (Kochi Pref.) Vitis ficifolia Bunge var. lobata (Regel) Nakai (Vitis thunbergii Sieb. et Zucc.) Ebizuru (z) All over Japan Vitis ficifolia Bunge var. izu-insularis Hara Shititouebizuru Izu Islands Vitis ficifolia Bunge var. sinuata Hara Kikubaebizuru Southern Honshu, Shikoku, Kyusyu Vitis ficifolia Bunge var. ganebu Hatusima Ryuukyuuganebu Amami Islands, Okinawa Islands, Yaeyama Islands Vitis austrokoreana Hatusima Kenashiebizuru Tsushima Islands Vitis kiusiana Momiyama Kumagawabudou Kyushyu (Kumamoto pref., Kagoshima pref.) Vitis shiragai Makino Shiragabudou Honshu (Okayama pref.) Vitis sp. Shiohitashibudou (tentative) Kyusyu (Kagoshima pref.) (z) used in some classifications as a species (thunbergii). Fig. 1 - Geographic distribution of Vitis coignetiae Pulliat (Nakagawa et al., 1986). Fig. 2 - Geographic distribution of Vitis flexuosa Thunb. (Nakagawa et al., 1986). 216 ping with the two species, and is found in slightly lower al- titude areas than Yamabudou (Fig. 1). We can usually find this species from the lowlands to the mountainous area of the Tohoku district or the Chubu district; it does not grow naturally in Hokkaido. Ebizuru, V. ficifolia Bunge var. lobata (Regel) Nakai (Fig. 3) This species is one of the most widespread Vitis species in Japan. Its distribution extends from the southern Hok- kaido region to the flatlands and mountainous terrain in the Okinawa district; it can be found in a wide variety of habitats, including both the seashore and urban districts. This species is considered to be highly adaptable to the environment, thus it has a wide distribution compared with other Vitis species. As a result, many variants of morpho- logical and physiological traits are found in this species as a result of adaptation to local climates. Ryuukyuuganebu, Shichitouebizuru, and Kikubaebizuru are varieties belong- ing to V. ficifolia. Kenashiebizuru is also closely related to V. ficifolia, although its scientific name is given as V. aus- koreana Hatusima. These grapes are generally included in the V. ficifolia group. Other species (Fig. 4) As shown in Table 1 and figure 4, in addition to these, many species and varieties are spread in various districts of Japan. Takeshimayamabudou, a variety of Yamabudou (V. coingnetiae), was discovered in Hokkaido (around Lake Akan) and Nagano prefecture. It has no hairiness on the lower leaf surface and a thinner leaf compared to Yam- abudou. Kumagawabudou has prickly shoots and ovoid leaves; one wild grape (V. davidii) with prickly shoots grows naturally in China, however, it differs significantly from Kumagawabudou in its morphological characteris- tics. Shichitouebizuru grows in seaside areas of seven is- lands of Izu. Moreover, its fruit-set is the highest among all wild grapes native to Japan. 3. The classification of Japanese wild grapes As genus Vitis is mainly classified by morphology, some taxa may be taken as different classifications even if they are the same grape. For example, Shiragabudou has two scientific names, Vitis shiragai Makino (Makino, 1918) and Vitis amurensis Rupr. (Ohwi, 1953). In this sec- tion, wild grapes native to Japan are classified concisely based on chemical, biochemical and genetic knowledge. Morphological classifications Classification by leaf structure. Galet (1979) tried to classify genus Vitis through ampelographic measurements Fig. 3 - Geographic distribution of Vitis ficifolia Bunge var. lobata (Re- gel) Nakai (Nakagawa et al., 1986). Fig. 4 - Geographic distribution of wild grapes native to Japan (Nak- agawa et al., 1986). 217 of the leaf (Fig. 5, Table 2). Nakagawa et al. (1991) coded the characteristics of grape leaves and the result is present- ed in Table 3. Code numbers of vein length rations (ABC) for the five basic leaf shapes are as follows (Galet, 1979): Cordiform: 357 to 468, Cuneiform: 135 to 247, Truncate: 045 to 247, Orbicular: 015 to 136, Reniform: 014 to 136. According to this method, code numbers are relatively near for close species (e.g. V. coignetiae and V. amurensis) (Table 3). Classification by pollen ultrastructure. Mochioka et al. (1993) observed ultrastructures of mature pollen grains of wild grapes native to Japan, Korea and China using a scanning electron microscope and reported that the pollen could be classified as one of three types by the lumina forms in muri (Fig. 6). They also reported the Table 2 - The code number of the Galet (1979) ruler for the values of A, B, C, r, S 1 and S 2 Code number Vales of A, B and C Vales of r Vales of S 1 Values of S 2 0 0.91~1.00 ≤0.80 ≤ 70° ≤ 100° 1 0.81~0.90 0.81~0.90 71°~80° 101°~110° 2 0.71~0.80 0.91~1.00 81°~90° 111°~120° 3 0.61~0.70 1.01~1.10 91°~100° 121°~130° 4 051~0.60 1.11~1.20 101°~110° 131°~140° 5 0.41~0.50 1.21~1.30 111°~120° 141°~150° 6 0.31~0.40 1.31~1.40 121°~130° 151°~160° 7 0.21~0.30 1.41~1.50 131°~140° 161°~170° 8 0.11~0.20 141°~150° 171°~180° 9 0.00~0.10 ≥151° ≥181° A= L 2 length/L 1 length; B= L 3 length/L 1 length; C= L 4 length/L 1 length, where L 1 = Midwein; L 2 = Superior lateral vein and L 3 = Inferior lateral vein; L 4 = Petiolar vein. r= Leaf length/leaf width. S 1 = α + β; S 2 = α + β + r where α= Angles between L 1 and L 2 . β= Angles between L 2 and L 3 . and r= Angles between L 3 and L 4 . Fig. 5 - The general morphology of a mature grape leaf. al.= Apical lobe; II= Lateral lobe; pl.= Proximal lobe; ss.= Superior sinus; is.= inferior sinus; ps. Petiolar sinus; pe.= Petiol; mv.= Mid- vein; sv.= Superior lateral vein; iv.= Inferior lateral vein; pv.= petiolar vein; vl.= Veinlet; se.= Serration; lm= Leaf margin. (Nakagawa et al., 1991). Table 3 - The code number of various wild grapes obtained by using the Galet’s method (Nakagawa et al., 1991) Species ABC-r-S 1 S 2 Vitis coignetiae 146-4-24 Vitis amurensis 146-3-24 Vitis flexuosa 357-7-01 Vitis ficifolia var. lobata 246-3-13 Vitis shiragai 136-3-13 Vitis sp. (Daisankakuzuru) 146-3-12 Vitis ficifolia Bunge var. ganebu 135-3-24 Vitis sp. (Shiohitashibudo) 257-5-02 Vitis ficifolia var. izu-insularis 146-3-01 Vitis kiusiana 368-7-01 Fig. 6 - Scanning electron microphotographs of grape exine. Scale bars= 1 µm. Type-1 A pollen has perforations in the lumina; type-1 B pollen has perforations and corrugation in the lumina, and type-II pollen has granules in the lumina (Mochioka et al., 1993). 218 pollen ultrastructures of related species belonged to the same type (Table 4). Chemotaxonomic classifications Classification by anthocyanins in grape skin. Mochioka et al. (1995) analyzed by HPLC anthocyanins in the berry skin of 10 wild grapes (four species, five varieties and one unidentified type) native to Japan. The dendrogram, show- ing phylogenetic relationships, was drawn from the pairwise comparison of matching coefficients based on anthocyanin Table 4 - Morphological characteristics of pollen grains of the wild grapes native to Japan, Korea and China (Mochioka et al., 1993) Species or cultivars Pollen size (µm) L/W ratio No. of colpi Pollen exine typeLength (L) Width (W) Japan Vitis coignetiae Pulliat ♂ 20.0±0.2 (z) 19.4±0.2 1.03±0.01 3 I A ♀ 22.0±0.2 20.7±0.2 1.06±0.01 0 I A Vitis flexuosa Thunb. ♂ 20.3±0.5 19.6±0.3 1.04±0.03 3 I A ♀ 20.6±0.2 20.1±0.2 1.03±0.01 0 I B, II Vitis ficifolia Bunge var. lobata (Regel) Nakai ♂ 20.0±0.2 19.2±0.2 1.04±0.01 3 II ♀ 20.9±0.2 20.0±0.2 1.05±0.01 0 II Vitis ficifolia Bunge var. izu-insularis Hara ♂ 20.9±0.3 20.1±0.4 1.04±0.01 3 II ♀ 21.4±0.2 20.2±0.2 1.06±0.01 0 II Vitis ficifolia Bunge var. ganebu Hatusima ♀ 21.4±0.3 20.3±0.2 1.05±0.01 0 I A Vitis shiragai Makino ♂ 21.1±0.2 20.7±0.2 1.02±0.01 3 I A ♀ 22.6±0.2 21.1±0.3 1.08±0.01 0 I A Vitis kiusiana Momiyama ♀ 20.4±0.2 19.5±0.2 1.05±0.01 0 I B Vitis sp. (provisional name: Shiohitashibudo) ♀ 21.3±0.3 20.0±0.3 1.06±0.01 0 II Korea Vitis amurensis Rupr. ♂ 20.6±0.3 20.1±0.2 1.03±0.01 3 I A ♀ 23.4±0.2 22.1±0.2 1.06±0.01 0 I B Vitis sp. (provisional name: Daisankakuzuru) ♀ 21.4±0.2 20.3±0.2 1.06±0.01 0 I B China Vitis amurensis Rupr. ♂♀ 21.5±0.2 20.7±0.2 1.04±0.01 3 I B Vitis flexuosa Thunb. ♂ 19.8±0.3 19.0±0.3 1.04±0.01 3 I A Vitis ficifolia Bunge ♂ 20.6±0.3 19.0±0.3 1.04±0.01 3 II Vitis adstricta Hance ♂ 21.5±0.2 21.2±0.2 1.02±0.01 3 II Vitis adstricta Hance var. ternata W.T. Wang ♂ 22.3±0.3 21.0±0.4 1.06±0.01 3 II Vitis bellula (Rehd.) W.T. Wang ♂ 19.3±0.3 18.8±0.2 1.03±0.01 3 II Vitis davidii (Roman.) Foëx ♂ 23.1±0.2 22.4±0.2 1.03±0.01 3 I B ♂♀ 20.4±0.2 19.9±0.1 1.03±0.01 3 I B Vitis pseudoreticulata W.T. Wang ♂ 21.3±0.2 20.8±0.2 1.03±0.01 3 I A Vitis hancokii Hance ♂ 20.1±0.2 19.6±0.1 1.03±0.01 3 I B Vitis chugii Metcalf. ♂ 19.9±0.2 19.3±0.2 1.03±0.01 3 I B Vitis chunganensis Hu ♂ 19.9±0.2 19.7±0.2 1.01±0.01 3 I A Cultivar Vitis vinifera L. ‘Muscat of Alexandria’ ♂♀ 23.2±0.4 22.4±0.4 1.03±0.01 3 I B Vitis lambrusca L. ‘Concord’ ♂♀ 23.3±0.3 22.9±0.3 1.02±0.01 3 I B Vitis lambruscana Bailey ‘Delaware’ ♂♀ 21.3±0.3 20.1±0.3 1.06±0.01 3 I B ‘Campbell Early’ ♂♀ 24.6±0.4 23.4±0.4 1.05±0.01 3 II ‘Kyoho’ (tetraploid) ♂♀ 28.2±0.3 26.9±0.3 1.05±0.01 3.4 I A (z) Each valure represents the mean of 20 individual measurements ±se. 219 components, and agrees well with the morphological tax- onomy (Fig. 7, Table 5) (Mochioka et al., 1995). In this study 19 anthocyanins were identified, and there were more kinds of anthocyanins in the berry skins of wild grapes distributed in southern regions than those of wild grapes distributed in northern regions (Table 5). Classification by isozyme and DNA analysis. Species- specificity was observed in the alleles dominated by Gpi- 2 and Pgm-2 gene loci (Fig. 8, Table 6) (Ohmi et al., 1991). The F band of Gpi-2 and the A and the C bands of Pgm-2 existed only in wild grapes native to East Asia (Table 6). While restriction fragment length polymorphism (RFLP) and random amplified polymorphic DNA (RAPD) analyses were used to analyze the relationships among wild and cultivated grapes, a phenogram of RAPD data obtained showed a clear separation between wild and cultivated grapes (Goto-Yamamoto et al., 1998). Fig. 7 - Dendrogram of berry skin anthocyanin phenotypes of wild and cultivated varieties (Mochioka et al., 1995). Table 5 - Percentage of anthocyanin composition in grape berry skins analyzed by HPLC (z) (Mochioka et al., 1995) Species or cultivars Peak No (y) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Wild grape Vitis coignetiae 1 4 66 1 4 2 1 18 2 V. amurensis 2 2 81 V. flexuosa 5 4 4 57 7 4 1 12 2 V. flexuosa var. rufo-tomentosa 2 1 28 3 3 2 1 4 1 38 2 8 V. ficifolia var. lobata 6 2 10 6 44 2 2 1 7 5 10 12 1 V. ficifolia var. izu-insularis 15 3 17 5 27 3 1 3 12 5 2 2 4 V. ficifolia var. ganebu 8 4 9 8 10 28 2 4 3 4 1 3 2 9 1 V. ficifolia var. sinuata 10 5 39 13 8 9 4 3 6 1 2 1 V. shiragai 11 7 5 13 15 26 2 1 3 4 2 2 2 4 V. kiusiana 13 10 28 19 11 1 1 6 3 3 2 1 V. sp. (tentative name: Shiohitashibudou) 6 3 2 10 15 37 2 6 1 1 4 1 1 2 2 V. sp. (tentative name: Daisankakuzuru) 5 3 28 17 12 7 7 4 3 2 3 2 2 3 V. sp. (tentative name: Taiwan kes- ankakuzuru) 5 2 24 6 36 1 8 3 3 2 2 2 3 Cultivars ‘Delaware’ 44 26 4 3 9 4 ‘Muscat Bailey A’ 3 21 4 32 23 2 2 1 2 2 1 2 ‘Campbell Early’ 6 6 12 46 6 2 7 6 (z) Absorbance at 520 nm. (y) Peak No. 3= delphinidia 3-monoglucoside, no. 5= cyaniding 3-monoglucoside; no. 9= petunidin 3-monoglucoside; no. 16= malvidin 3-monoglucoside. Fig. 8 - GPI and PGM isozymes bands coded by each alleles at Gp1-2 (left) and Pgm-2 (right) loci (Ohmi et al., 1991). 220 Classification by general judgments Since the past horticultural plant classification was qualitatively performed considering a small number of characteristics, a different result for some researchers might be found (e.g. Shiragabudou). Therefore, using plu- ral classification methods is desirable because just one method might induce the wrong result. What follows is a brief discussion of judgments about some Japanese wild grapes with questionable taxonomic points. Shiragabudou. Shiragabudou was discovered in Okayama prefecture, Honshu and was first named by Makino (1918). As the leaf shape of this wild grape re- sembles that of V. amurensis Rupr. Ohwi (1953) changed its scientific name to Vitis amurensis Rupr. The leaf morphology and pollen ultrastructures of these two wild grapes are in the same group (Table 3, 4), but anthocyan- in composition in berry skins (Table 5) and species-spe- cific alleles at 2 loci (Table 6) are apparently different. Furthermore, ecological differences exist between Shi- ragabudou and V. amurensis. Shiragabudou is distributed over the warm lowland from 20 to 240 m above sea level in Okayama while V. amurensis has a growth area in the cold districts at 40 to 50° N latitude. The cross section morphology of Shiragabudou shoots is hexagonal, while that of V. amurensis is circular. These differences show that Shiragabudou and V. amurensis are not the same species, thus Vitis shiragai Makino should be used as the scientific name for Shira- gabudou. Ebizuru and its varieties. Ebizuru is distributed wide- ly in Japan. There are a number of varieties and ecotypes in the Ebizuru group, and morphological differences are various. Even if they are the same species, there are sev- eral synonyms for this group. Even now, Vitis ficilolia, V. ficifolia var. lobata, and V. thunbergii are used as scientif- ic names for Ebizuru. An isotype of V. ficifolia is the wild grape native to China. There are definitely differences in leaf morphology and bearing habit between Chinese fici- folia and Japanese Ebizuru. Natural hybrids. Different Vitis species can be hy- bridized easily with each other, so there are many natural hybrids. V. yokogurana is supposed to be a hybrid of V. flexuosa and V. saccharifera (Makino, 1918); V. flexuosa var. tukubana is supposed to be a hybrid of V. flexuosa and V. ficifolia var. lobata (Murata, 1971). Yamabudou. Yamabudou (V. coignetiae) must be a species related to V. amurensis, but there is no report that both these two species are simultaneously distributed over the same regions in Japan or other countries. Shiohitashibudou. (tentative name): Shiohitashibu- dou is an unidentified species, and it was discovered in Kagoshima prefecture, Kyushu (Nakagawa et al., 1991). Its leaf morphology is definitely different from that of other Japanese wild grapes. Shiohitashibudou might be a related species or natural hybrid of Ebizuru because its flowering habit is ever-bearing and the pollen ultra- structure is type II. Its bud endodormancy is deeper, and the soluble solid content of its juice is higher than other Japanese wild grapes (Mochioka, 1996). Ryuukyuuganebu. Ryuukyuuganebu is distributed over Amami, Ryukyu and Yaeyama Islands, and is sup- posed to be a variety of V. ficifolia. However its leaf shape is different from V. ficifolia var. lobata (Fig. 9, Table 3), and its pollen ultrastructure is also different (Table 4). Ryuukyuuganebu is ever-green in its habitat. 4. Physiological and ecological traits of wild grapes na- tive to Japan Four species [V. coignetiae, V. flexuosa, V. shiragai, and Shiohitashibudou (tentative name. Vitis sp.)] and two va- rieties (V. ficifolia var. lobata and V. ficifolia var ganebu ) of wild grapes native to Japan, and two species [Chosen Yamabudou (V. amurensis) and Daisankakuzuru (tentative name. V. sp.)] grown in Korea, and ‘Delaware’ (V. labrus- Table 6 - Species-specific alleles at 2 loci in grape (Ohmi et al., 1991) Locus Allele Species (z) Gpi-2 A Vin. B Vin., Amur. (?) C Lab., Rip. (?) D Vin. E Lab., Shir. F Thun., Shir. G Vin., Amur. H Lab., Aest. (?), Vulp (?) I Lab., Rup., Champ., Linc. (?), Coig., Shir. J Bourq. and/or Lab. K Champ. L Vulp. and/or Lab. Pgm-2 A Shir. B Vin. C Amur., Coig., Thun., Shir. D Vin. E Vin. F Lab. and/or Linc. G Lab., Aest. (?) H Vin., Rup., Champ., Lab., Coig., Aest. (?), Bourq. (?), Rip. (?), Vulp. (?) I Vin. J Rup. K Champ. (z) Abbreviations: Amur.= Vitis amurensis; Aest.= V. aestivalis; Bourq.= V. aestivalis var. bourquiana; Champ.= V. champini; Lab.= V. labrusca; Linc.= V. lincecumii; Rip.= V. riparia; Rup.= V. rupestris; Shir.= V. shi- ragai; Tun.= V. thunbergii (=V. ficifolia var. lobata); Vin.= V. vinifera; Vulp.= V. vulpina. 221 cana Bailey) (Table 7) were cultivated in the Horticultural Experiment Field at Osaka Prefecture University (Sakai, Osaka) and their physiological and ecological traits were compared (Nakagawa et al., 1986). Here, Chosen Yamabu- dou is a wild grape grown naturally in the northern and northeastern regions of China, northern region of Korea and southeastern region of the former Soviet Union. The results are illustrated below. Growth cycle Bud burst. Bud burst of Yamabudou and Chosen Yam- abudou occurred earlier among the wild grapes, followed by Sankakuzuru, Ebizuru, and Daisankakuzuru. Shiohi- tashibudou showed the latest bud burst in this study (Table 7). ‘Delaware’ broke bud later than all wild grapes except for Shiohitashibudou. Full bloom (50% cap off). In grape cultivation, early bud burst does not always mean early bloom. Indeed, the orders of bloom date differed from those of bud burst (from early to late bloom): Yamabudou, Sankakuzuru Ebi- zuru/Shiragabudou, Daisankakuzuru, Shiohitashibudou, and Ryuukyuuganebu. Here, Ebizuru blooms in the same period as Shiragabudou, and the bloom date of Sankaku- zuru was comparable to that of ‘Delaware’ (Table 7). Veraison (berry coloring begins). The skin color of Yamabudou changed earliest among the wild grapes. Changes in skin color in Chosen Yamabudou and ‘Dela- ware’ occurred on the same date. Skin color change oc- curred the latest in Daisankakuzuru, Shiohitashibudou, and Ryuukyuuganebu; and Sankakuzuru, Shiragabudou and Ebizuru were the next to latest (Table 7). Maturity. Maturity is denoted when berry weights and soluble solids attain maximum maturation. ‘Delaware’ matured in mid-August, which was earlier than the studied wild grapes. Sankakuzuru and Ryuukyuuganebu matured in mid-September and Daisankakuzuru in early-October (Table 7). Thus, wild grapes tend to have medium to late maturation in Osaka. Defoliation. Defoliation indicates the date when all leaves (from basal to tenth leaf) fall completely. Defo- liation in Sankakuzuru and Daisankakuzuru took place in early-November, Yamabudou and Chosen Yamabudou shed their leaves in mid-November, and Shiohitashibudou, Ebizuru, and Shiragabudou in late-November. Interest- ingly, Ryuukyuuganebu, a subtropical grape, showed ex- tremely late defoliation; in some cases, leaves did not fall until January. Characteristics of organ Shoot. Observations of shoot growth in summer en- abled us to classify the wild grapes into three types: con- tinuous, subcontinuous, and discontinuous. The continu- Table 7 - Growth cycle of wild grapes native to Japan at Sakai Osaka (Nakagawa et al., 1986) Species and varieties Bud burst Full bloom Veraison Harvest Leaf fall Chosen yamabudou (V. amurensis Rupr.) 3/27 5/14 8/1 9/29 11/14 Yamabudou (V. coignetiae Pulliat) 3/27 5/12 7/26 9/29 11/13 Sankakuzuru (V. flexuosa Thunb.) 3/29 5/26 8/6 9/14 11/7 Ebizuru [V. ficifolia Bunge var. lobata (Regel) Nakai] 3/29 6/4 8/11 9/11 11/27 Shiragabudou (V. shiragai Makino) 3/29 6/4 8/6 9/15 11/23 Daisankakuzuru (tentative Vitis sp.) 3/29 6/10 9/4 10/6 11/4 Shiohitashibudou (tentative Vitis sp.) 4/10 6/13 9/4 9/22 11/25 Ryuukyuuganebu (V. ficifolia Bunge var. ganebu Hatusima 4/3 6/19 8/31 9/20 after end of Dec. Delaware (V. labruscana Bailey) 4/6 5/27 7/30 8/20 11/8 Fig. 9 - Standard design of mature leaf of various wild grapes (├─┤ 1 cm) (Nakagawa et al., 1991). 222 ous group had constant growth of some shoots in summer; Shiohitashibudou and Daisankakuzuru were included in this type. The subcontinuous type exhibited slight growth of some shoots in summer; Ryuukyuuganebu, Sankakuzu- ru, Ebizuru, and Shiragabudou corresponded to this type. Finally, the discontinuous group stopped shoot growth in summer, for example Yamabudou and Chosen Yamabudou in this study. Tendril placement of all Vitis species and va- rieties native to Japan is intermittent. Inflorescence. Wild grapes native to Japan (seven spe- cies and eight varieties) are dioecious, meaning that they contain imperfect individual male and female plants. Three types of fruiting habits were found (Fig. 10). “A” type: as is the case of Yamabudou, Chosen Yamabudou, Sankakuzu- ru, Daisankakuzuru, Shiragabudou, and Kumagawabudou, with two to four inflorescences at the basal part on each shoot without any inflorescences on lateral shoots. “B” type: as seen in Shiohitashibudou, Shichitouebizuru, and some Shiragabudou, there are two to four inflorescences at the basal part on each shoot with some inflorescences on lateral shoots. “C” type: Ebizuru and Ryuukyuuganebu be- long to this type, with two to six inflorescences at the basal part and the upper part of each shoot, having contiguous inflorescences from the base to the top of lateral shoots. Grape comparison and fruit quality (Table 8) Sugars. Shiohitashibudou attained a sugar concentra- tion of 17.7%, which is the highest among the other spe- cies (measured as 12-14%) except Ebizuru and Ryuukyuu- ganebu, which had sugar concentrations of around 8%. Almost all studied species have high glucose content, especially Kumagawabudou, Shiohitashibudou, and Dai- sankakuzuru, which contained two to three fold more glu- cose than fructose. Acids. Kumagawabudou and Daisankakuzuru contained about 0.7 and 0.8% of organic acids, while almost all other species contained about 0.5%; Shiragabudou showed the lowest level of organic acids (0.36%) (Table 8). Amino acids. The concentration of amino acids var- ied widely from 50 mg% (Ebizuru) to 294 g% (Shiohi- tashibudou). Anthocyanins. Northern species such as Yamabudou and Chosen Yamabudou showed small amounts of antho- cyanin, while the southern species, Ryuukyuuganebu, con- tained a larger amount of this component (Table 8). Dormancy and cold hardiness Dormancy. Although all species have a dormancy trait, its intensity depends on the species. Ryuukyuuganebu showed a short dormancy period, while it was generally longer in Kumagawabudou and Shiohitashibudou (Nak- agawa et al., 1986; Nakagawa, 1989). Cold hardiness. Cold hardiness varied markedly among the wild grapes. For example, Ryuukyuuganebu and Ku- magawabudou were very susceptible to severe damage at -3°C. On the contrary, Yamabudou, Ebizuru, Shiragabu- Fig. 10 - Fruiting habit of wild grapes native to Japan. Table 8 - Berry composition of wild grapes native to Japan (Nakagawa et al., 1986) Species and varieties Reducing sugars (%) Glucose (%) Fructose (%) Glucose/ Fructose Organic acid (%) Amino acid (mg %) Anthocuanin (OD 537 nm) Chosen yamabudou (V. amurensis Rupr.) 12.7 9.2 3.5 2.6 0.50 191.2 0.12 Yamabudou (V. coignetiae Pulliat) 12.3 5.2 7.1 0.7 0.50 155.3 0.21 Sankakuzuru (V. flexuosa Thunb.) 14.2 8.0 6.2 1.3 0.52 214.0 0.30 Ebizuru [V. ficifolia Bunge var. lobata (Regel) Nakai] 8.1 4.1 4.0 1.0 0.51 50.7 0.30 Shiragabudou (V. shiragai Makino) 12.0 6.7 5.3 1.3 0.36 222.6 0.45 Daisankakuzuru (tentative Vitis sp.) 12.3 8.1 3.9 2.2 0.81 250.8 0.42 Kumagawabudou (V. kiusiana Momiyama) 12.0 9.2 2.8 3.3 0.72 180.5 0.49 Shiohitashibudou (tentative Vitis sp.) 17.7 12.7 5.0 2.5 0.48 294.5 0.41 Ryuukyuuganebu (V. ficifolia Bunge var. ganebu Hatusima 7.8 3.7 4.1 0.8 0.51 138.0 0.70 Delaware (V. labruscana Bailey) 16.8 7.5 9.3 0.8 0.77 220.8 0.05 223 dou, Shichitouebizuru, and Chosen Yamabudou showed moderate cold hardiness; their survival has even been re- ported at -10°C (Nakagawa, 1989). 5. Value and use of wild grape germplasms in Japan Wine Between the 1960s and 1980s, Yamabudou was suc- cessfully cultivated in commercial vineyards for wine- making in the town of Ikeda (Hokkaido); its cultivation has attracted attention as a means to revitalize towns in Japan. In China, V. quinquangularis is processed into an excellent wine (Li et al., 1992). Kumagawabudou, which is thought to be the same species as V. quinquangularis (Li et al., 1991), therefore, may be an important resource for wine making. Breeding The major cultivars, bred using wild grapes, are ‘Sawanobori Waingurando’ and ‘Yama Sauvignon’ in Ja- pan, both of which are used for wine production. ‘Sawa- nobori Waingurando’ is a cross seedling of V. amurensis × (Seibel 13053 × Nakajima No.1, a strain of Yamabu- dou) and it was released in 1998. By contrast, ‘Yama Sauvignon’ is a progeny of Yamabudou × ‘Cabernet Sauvignon’, which was released in 1990 by Dr. Yoshi- hide Yamakawa at the University of Yamanashi. ‘Yama Sauvignon’ has the following superior characteristics: 1) no cracking of berry; 2) resistance to ripe rot, downy mildew, and gray mold; 3) adaptability to the prevailing weather conditions in Japan; 4) high productivity; and 5) high quality wine with typical aroma and taste (Ya- makawa et al., 1989). Considering the potential use of wild grapes as breeding material, these grapes have the following notable charac- teristics: drought resistance, cold hardiness, salt tolerance, water logging tolerance, heat tolerance, disease resistance, high concentration of important substances, ever bearing, and short dormancy. Four characteristics are especially promising: i) ever bearing, ii) short dormancy, iii) salt tol- erance, and iv) heat tolerance. Therefore, we explain the usefulness of these characteristics for grape breeding pro- grams in more detail. i) Ever bearing Strains of Ryuukyuuganebu and Ebizuru bloom and fruit as long as the growth of axillary buds continues. This trait makes it possible to carry out year-round culture and/ or culture using a factory system, like some vegetables, us- ing artificial light and controlled irrigation. However, the major gene related to this trait has not yet been identified. ii) Short dormancy Ryuukyuuganebu can be released from dormancy af- ter being subjected to low temperature for extremely short periods. This trait may be profoundly related to ever bear- ing. Thus, it may be possible to force culture inside green- houses due to the low cost, for year-round culture and/or culture using a factory system. iii) Salt tolerance Salt accumulation through the use of chemical fertilizers causes serious problems which sometimes result in the loss of plants. Shiohitashibudou is excellent in its resistance to salts and Ryuukyuuganebu grows naturally along the sea- shore. Although the mechanism underlying salt tolerance of this grape has not yet been fully elucidated, this trait could be useful not only for scion but also for root stock. iv) Heat tolerance As global warming progresses, fruit skin, including grape, shows poor coloration, which leads to a defective appearance and reduced commercial value. Poor coloration also affects wine production. Interestingly, the coloration of wild grapes native to Japan is very high, even under high temperature conditions during their ripening season. In grape, since MYB is involved in red skin coloration, it is valuable to compare MYB genes between wild grapes and primary Japanese cultivars such as ‘Kyoho’ and ‘Aki Queen’. Thus, this trait could be useful for sustainable grape production with high quality and high adaptability in the production area. 6. Conclusions Wild grapes native to Japan have been actively stud- ied over a long period, but in recent years attention has declined. However, wild grapes native to Japan can of- fer many useful characteristics, such as short dormancy, ever bearing, heat and salt tolerance. These traits are very attractive, not only for their use as rootstock, but also in terms of breeding material or for genetic studies. We have recently begun a breeding study using Ryuukyuuganebu. It is expected that some novel grapes will be bred to with- stand increasing global temperatures or for use in grape cultivation factories. References GALET P., 1979 - A practical ampelography: Grapevine iden- tification. - Cornell University Press, New York, USA, pp. 24-47. GOTO-YAMAMOTO N., MOCHIOKA R., LIN B., HASHI- ZUME K., UMEDA N., HORIUCHI S., 1998 - RFLP and RAPD analysis of wild and cultivated grapes (Vitis spp.). - J. Japan. Soc. Hort. Sci., 67: 483-490. HORIKAWA Y., 1972 - Yamabudo. Atlas of the Japanese flora: An introduction to plant sociology of East Asia. - Gakken Co., Ltd., Tokyo, Japan, pp. 208. HORIUCHI S., MATSUI H., 1996 - Nihon Budougaku. - Yok- endo, Tokyo, Japan, pp. 58-102. LI S.C., HORIUCHI S., MOCHIOKA R., MATSUI H., 1992 - Some issues on wild grapes native to East Asia (2). - Agric. Hortic. (Nogyo-oyobi-Engei), 67: 1277-1280. LI S.C., HORIUCHI S., MOCHIOKA R., YAMAZAWA M., MATSUI H., 1991 - Comparison between wild grapes native to Japan and China. 2. Study on morphological character- 224 istics of V. kiusiana and V. quinquanglaris. - J. Japan. Soc. Hort. Sci., 60(Suppl. 1): 132-133. MAKINO T., 1918 - A contribution of the knowledge of the flora of Japan. - J. Jpn. Bot., 1: 31-33. MOCHIOKA R., 1996 - Taxonomic classification and utiliza- tion on wild grapes native to Japan based on their various characteristics. - Ph. D. Thesis, Osaka Prefec. University, Sakai, Japan. MOCHIOKA R., HORIUCHI S., LI S.C., MATSUI H., MURAI Y., 1993 - Pollen morphology of wild grapes native to East- ern Asia. - Jpn. J. Palynol., 39: 11-20. MOCHIOKA R., YAMAGUCHI M., HORIUCHIL S., MAT- SUI H., KUROOKA H., 1995 - Chemotaxonomic classifica- tion of native wild Japanese grapes by anthocyanins in berry skin. - J. Japan. Soc. Hort. Sci., 64: 463-470. MURATA G., 1971 - Vitaceae, pp. 237-241. - In: KITAMURA S., and G. MURATA (eds.) Genshoku-Nippon-no-Shokubut- suzukan (Mokuhonhen I). Hoikusha, Osaka, Japan. NAKAGAWA S., 1989 - Studies on collection, preservation and usage of gene resorces in fruit trees. - Report for Grants in Aid for Scientific Research, pp. 10-20. NAKAGAWA S., HORIUCHI S., MATSUI H., YUDA E., 1986 - Studies on the cultivation and use of the wild grapes native to Japan. - Report for Grants in Aid for Scientific Research, pp. 1-49. NAKAGAWA S., HORIUCHI S., MATSUI H., YUDA E., YA- MADA S., MURAI Y., KOMATSU H., 1991 - Distribution and leaf morphology of wild grapes Native to Japan. - J. Ja- pan. Soc. Hort. Sci., 60: 31-39. OHMI C., WAKANA A., SHIRAISHI S., 1991 - Phylogenic im- plication of genus Vitis on the basis of isozyme analysis. - J. Japan. Soc. Hort. Sci., 60(Suppl. 2): 62-63. OHWI J., 1953 - Vitis Linn. Flora of Japan. - Shibundo, Tokyo, Japan, pp. 760-762. YAMAKAWA Y., MORIYA M., ANAMIZU H., 1989 - Char- acterization of hybrid new red-wine grape cultivar ‘Yama Sauvignon’. - J. Inst. Enol. Vitic. Yamanashi Univ., 24: 15-24.