植物研究雑誌 J. J. Jpn. Bo t. 76: 76: 329-338 (200 1)

Variation Variation in Shoot Organization in () with with Special Reference to Prunus ogawana

c Ak itoshi Iw AMOTO¥ Keiko MIY AZA 阻 b and Jin MURATA

aUniversity aUniversity Museum ， the University of Tokyo ， Hongo 7-3-1 ，Bunkyo-ku ，Tokyo ，113 ・0033 ; bMakino bMakino Herbarium ，Tokyo Metropolitan University ， Minamiosawa 1-1 ，Hachi 吋i，Tokyo ， 192-0397 JAPAN; [Present address: address: [Present Matsubara 3-39-29 ，Setagaya-ku ，Tokyo ， 156-0043 JAPAN] CBotanical CBotanical Gardens ， Graduate School of Science ， the University of Tokyo ，

Hakusan 3-7-1 ，Bunkyo-ku ，Tokyo ，112 ・0001 JAPAN

(Received on May 11 ，2001)

To determine variation in shoot development in Prunus (Rosaceae) ，we observed and and compared the shoot organization of 13 species (9 species of subgen. Cerasus sec t. Pseudocerasus; Pseudocerasus; 1 species of sec t. Microcerasus; 1 species of sec t. Phyllomahaleb; 1 spe- cies cies of Prunus; subgen. and 1 species of subgen. Padus). As a result ，we can categorize the the observed species into four distinct groups based on shoot organization of 1) types of winter winter bud growth ， 2) growth of buds in the axils of scale-like prophylls ， and 3) shoot ab- scission. scission. The first group includes all species of subgen. Cerasus sec t. Pseudocerasus and sec t. Phyllomahaleb except P. ogawana. The second group includes only P. ogawana ， the third third group contains P. mume and P. glandulosa ， and the fourth group contains only P. grayana. grayana. Prunus ogawana (subgen. Cerasus sec t. Pseudocerasus) is distinct from other

members of sec t. Pseudocerasus in that some winter buds develop into mixed shoots pro ・ ducing ducing both and ， and some buds in the axils of scall-like prophylls grow into into vegetative shoots. In addition ， this grouping is basically supported by the phylogenetic phylogenetic DNA analysis of Prunus.

Key words: Prunus ， Prunus ogawana ， Prunus subgenus Cerasus ， shoot organization

Introduction Introduction to determine the degree of variation between Prunus (Rosaceae) ， comprising about 200 them. We especially focused on P. ogawana species ， has been usually classified into sev- Makino (subgen. Cerasus sec t. Pseudocera- eral eral subgenera (Rehder 1940 ，Gohra and sus). The species usually blossoms within Panigrahi Panigrahi 1995). Ohba (1989) recognized three ye 訂 s of germination (Makino 1906) ， five five subgenera (Prunus ，Amygdalus ，Padus ， while other species of Prunus usually need Laurocerasus ， Cerasus) in J apan. There are 10-15 years for flowering. Additionally ， the some references to shoot organization in species produces fertile seeds that can rela- Prunus in the descriptions of the species ， but tively easily propagate. Hence ， Prunus critical critical comparative studies have not been ogawana was expected to be suitable for ex-

conducted. conducted. We observed the shoot organiza 四 perimental studies of formation in tion tion of species of 13 Prunus (mainly Prunus using genetic recombinant methoas. J apanese wild species) to comp 訂 e them and Flowering at a juvenile stage has been

-329 ー 330 植物研究雑誌 第76 巻 第6号 平成13 年12 月 considered considered to be the only distinct characteris- subgen. Cerasus sec t. Phyllomahaleb (P. tic tic differentiating it from other species of maximowiczii). Th e materials used in this sec t. Pseudocerasus. Our preliminary obser- study 訂 e shown in Table 1. We observed de- vations vations revealed that all winter buds develop tails of the shoots macrographically. A into into shoots with flowers. This feature does stereoscopic microscope was used to observe not not occur in other species of Prunus and axillary bud organization. shows shows that the shoot organization of P. ogaw αna may be unique. Detailed observa- Results tions tions of shoot organization in P. ogawana F eatures observed and and of other phylogenetically closely related We determined that 伽 ee features were species species of Prunus 紅 'e necess 紅 Y to ascertain important for analyzing shoot organization; that that the feature is species-specific. (1) type of winter bud growth ， (2) growth of buds buds in the axils of scale-like prophylls and Materials Materials and Methods (3) shoot abscission. Observations of each We observed shoots of 13 species of item 紅 e as follows: Prunus throughout two years (from April 1998 1998 to March 2000) using living and (1) Types of winter bud growth sample sample branches obtained from the 佐ees. All the species examined in this study 訂 e Among 13 species ， nine belong to subgenus and all new shoots extend from Cerasus Cerasus sec t. Pseudocerasus ， the other four winter buds. The winter buds of species of belong belong to: subgen. Prunus (P. mume) ， Prunus usually develop into one of three subgen. subgen. Padus (P. grayana) ，subgen. Cerasus types: (1) a vegetative shoot that produces sec t. Microcerasus (P. glandulos α) and some leaves and no flowers ， (2) a reproduc-

Table Table 1. Observed materials of Prunus s. 1. in this study. Scientific names 訂 e 紅 ranged according to Ohba (1 989)

Subgenus Subgenus Section Species Source*

Cerasus Cerasus Phyllomahaleb maximowiczii Rupr. IV wwwwwwww Pseudocerasus Pseudocerasus apetala (Siebold & Zucc.) Franch. & Sav. cerasoides cerasoides D. Don v訂 . campanulata (Maxim.) Koidz. incisa incisa Thunb. YEAYE-TEly-- jamasakura Siebold ex Koidz. 11 111 pendula pendula Maxim. f. ascendens (Makino) Ohwi sargentii sargentii Rehder speciosa speciosa (Koidz.) Nakai verecundi α(Koidz.) Koehne 111 ogawana Makino 11

Microcerasus Microcerasus glandulosa Thunb. IV

Prunus Prunus mume (Siebold) Siebold & Zucc. IV

Padus Padus grayana Maxim. IV

Source. * Source. 1: Tokyo Metropolitan University. 11: Botanical Gardens Koishikawa ， Graduate School of Science ， the University of Tokyo. 111: Botanical Gardens Nikko ， Graduate School of Science ， the University University of Tokyo. IV: Tama Forest Science Garden. December December 2001 Joumal of Japanese Botany Vo l. 76 No. 6 331

F

-p reproductive reproductive shoot reproductive reproductive shoot

(a) (a) (b)

vegetative vegetative shoot vegetative shoot

(c) (c) (d)

Fig. Fig. 1. Types of winter bud growth in Prunus s. 1. (a) Winter buds grow into both reproduc- tive tive shoots and vegetative shoots. (b) All winter buds grow into shoots with flowers. Some shoots also develop leaves (mixed shoots). (c) Winter buds grow into only vege- tative tative shoots. (d) All winter buds grow into shoots with leaves. F: flower. B: brac t. L: lea f. S: scale-like . P: scale-like prophylls of winter buds. Arrows indicate indefinite shoots. shoots. 332 植物研究雑誌第76 巻第6号 平成 13 年12 月

tive tive shoot that produce some flowers and no (c) Growth into only vegetative shoots leaves leaves or (3) a mixed shoot that produce both All winter buds grow into vegetative flowers flowers and leaves. We also found that the shoots in this type and no shoots with flow-

species species of Prunus produce three kinds of ers were found. Buds in the axils of scale 田 winter winter buds in various combinations ， which like prophylls also show shoot elongation of are are illustrated in Fig. 1. another type (see (2) Growth of buds in the (a) (a) Growth into reproductive shoots and axil of scale-like prophylls). The species vegetative vegetative shoots which show this type are P. mume and P. Winter Winter buds produce a reproductive shoot glandulosa. and and a vegetative shoot in this type. No buds (d) Growth into vegetative shoots and develop develop into a mixed shoo t. An apical bud is mixed shoots more likely than a lateral one to grow into a All winter buds develop leaves and some- vegetative vegetative shoo t. The species that show this times also produce some flowers. The spe- type type are P. jam αsakura ， P. verecunda ， P. cies showing this type is P. grayana. sargentii ， P. speciosa ， P. pendula ， P. cerasoides ， P. incisa ， P. apelata and P. (2) Growth of buds in the axils of scale-like maxzmowzcZll. maxzmowzcZll. prophylls (b) (b) Growth into reproductive shoots and Some species of Prunus have buds in the mixed shoots axils of scale-like prophylls of the winter All All winter buds produce flowers. In addi- buds (we call the bud in the axil of a leaf the tion ，some of them also develop some leaves ， main bud to distinguish it from the buds in

but but buds in the axils of scale-like prophyll the axils of scale 田 like prophylls) (Fig. 2). show shoot elongation of another type (see The prophyll buds do not appear to expand (2) (2) Growth of buds in the axil of scale-like soon ， but a study by Guo et al. (1992) im- prophylls). prophylls). The species showing this type is plied that such buds in P. persica regul 紅 ly P.ogawana. develop into shoots. Our observations re- vealed vealed that the axillary buds show a variety

Aowers …s (altemate) (altemate)

Buds in 鉱 il of of a scale-like prophyll

Fig. Fig. 2. Structure of winter bud (a mixed bud) in Prunus s. L Flower buds produce no leaves and vegetative buds produce no flowers. Meaning of symbols are same as as those in Fig. 1. December December 2001 Journal of Japanese Botany Vo l. 76 No. 6 333

r--hu、.， (a) (a) ‘、J

\判各例舛~

L ‘

(d) (d)

Fig. Fig. 3. Growth of buds in the axil of scale 回 like prophylls in Prunus s. l. (a) Buds in the axile of scale-like prophylls prophylls do not develop. (b) Buds in the axile of scale-like prophylls of mixed shoots develop into vegetative vegetative shoots. (c) All buds in the axile of scale-like prophylls develop into reproductive shoots. (d) Buds in the axil of scale-like prophylls develop vegetative and mixed shoots in following yea r. Shoots

indicated indicated by broken lines extend one ye 訂 after shoots in solid lines develop. Shoots within solid ellipse

訂 e derived from main buds; shoots in broken ellipse extend from buds in axil of scale-like prophylls of main buds. Meaning of symbols are same as those in Fig. 1.

of of growth pattems ， for which we can distin- shoo t. Shoots which have no leaves were guish guish four types (Fig. 3). more likely to develop these axillary vegeta- (a) (a) B uds in the axils of scale-like tive shoots than shoots with leaves. A single prophylls prophylls not developing bud in either axil of two scale-like prophylls Axillary Axillary buds were recognizable rarely in grows into a vegetative shoo t. The species the the axils of winter scale-like prophylls ， or if showing this type is P. ogawana.

they they were present the bud hardly expands. )c( All buds in the axils of scale 回 like The species exhibiting this type are prophylls develop into reproductive shoots P. P. jamasakura ， P. verecunda ， P. sargentii ， Almost all buds in the axils of the scale- P. P. speciosa ， P. pendula ， P. cerasoides ， P. like prophylls grow into reproductive shoots. incisa ， P. apelata and P. maximowiczii. Buds in both axils of two scale-like (b) (b) Some buds in the axils of scale-like prophylls expand. They also grow into prophylls prophylls develop into vegetative shoots shoots in the same ye 紅 when the main buds The bud in the axil of scale-like prophylls developed. The species showing this type are of of a new shoot sometimes grows into a vege- P. mume and P. glandulos α. tative tative shoot in the same year as the new (d) All buds in the axils of scale-like 334 植物研究雑誌 第76 巻 第6号 平成13 年12 月 prophylls prophylls develop into new winter buds while all vegetative shoots persist to develop Nearly Nearly all buds in the axils of the scale- new shoots from their axillary buds in the like like prophylls develop into winter buds that following year. The species showing this grow into vegetative or mixed shoots in the type are P. jamas αkura ， P. verecunda ， following following year of main bud expansion. A P. sargentii ， P. speciosa ， P. pendula ， P. single single bud in either axil of two scale-like cerasoides ， P. incisa ， P. αrpelata ， P. prophylls prophylls grows into a vegetative shoot or maximowiczii ， P. mume and P. glandulos α. mixed shoo t. That is ， buds in the axils of (b) Reproductive shoots abscising; vegeta-

scale 四 like prophylls become new winter tive and mixed shoots persisting buds. buds. The species with this type is P. All reproductive shoots abscise and all g 1i αyαnα. vegetative shoots persis t. In addition ，mixed shoots shoots also persis t. That is ， any shoots with (3) (3) Shoot abscission leaves do not abscise. The species showing Species Species of Prunus usually abscise repro- this type is P. ogawana. ductive ductive shoots by the end of the flower sea- (c) All shoots abscising son ， while vegetative shoots persis t. But All shoots ，irrespective of the type ，usually extraordinary extraordinary abscission has been reported in abscise by the of winter the shoot extension P. P. grayana. Our observations also revealed except the terminal vegetative shoots. As a variation variation in shoot abscission pattems in this result ， shape with a simple branching species. species. We recognized three types in this pattem is formed. The species exhibiting this character character (Fig. 4). type is P. grayana. (a) (a) Reproductive shoots abscising; vegeta- tive tive shoots persisting All All reproductive shoots abscise by winter ， 主主、が

terminal terminal shoot

Q 的 校一・・ぶU 込 JF JF ~・..1

(a) (a) (b) (c)

Fig. Fig. 4. Shoot abscission in Prunus s. 1. (a) Reproductive shoots abscise ， while vegetative shoots per- t. sis t. (b) Mixed shoots and vegetative shoots persis t. Reproductive shoots abscise. (c) All shoots except except terminal ones abscise. Solid lined shoots persists and broken lined shoots abscise. Meaning of syrnbols ぽ e sarne as those in Fig. 1. December December 2001 Joumal of Japanese Botany Vo l. 76 No. 6 335

Table Table 2. Result of observation on Prunus s. 1. in this study. It em 1: Types of winter bud growth. It em 2: Growth Growth of buds in the axils of scale-like prophylls. It em 3: Shoot abscission. See the text for explana- tion tion of the Groups I-IV

Subgenus Subgenus Section Species Item 1 It em 2 Item 3 Group

Cerasus Cerasus Phy llomahaleb Prunus m ω imowiczii a a a III-III-H Pseudocerasus Pseudocerasus P. apetala aaaaaaaaLUaaaaaaaabaaaaaaaab P. P. cerasoides P. P. incisa P. P. jamasakura P. P. pendura P. P. sargentii P. P. speciosa P. P. verecunda P.ogawana

Microcerasus Microcerasus P. glandulosa C C a III

Prunus Prunus P.mume C C a III

Padus Padus P. grayana d d C IV

Discussion Discussion abscise ， while the shoots with leaves (mixed Grouping of observed species on the shoot and vegetative shoots) persis t. orgamzatwn Group III [Prunus mume ， P. glandulosa] We can categorize the observed species All winter buds develop into vegetative into into four groups based on our observation of shoots and buds in the axils of scale-like the the three types of shoot organization (Table prophylls develop into reproductive shoots 2). 2). Detailed descriptions of each group are as simultaneously. All reproductive shoots ab- follows: follows: scise and all vegetative shoots persis t. Group 1 [Prunus jam αsakura ， P. verecunda ， Group IV [Prunus grayana] P. P. sargentii ， P. speciosa ， P. pendula ， P. Mixed shoots and vegetative shoots de- cer α， soides ， P. incisa ， P. αrpetala ， P. velop from winter buds. The winter buds are maximowiczii] maximowiczii] derived from smaller winter buds in the axils In In these species the buds in the axils of of scale-like prophylls. All shoots except the leaves leaves produce vegetative and reproductive terminal ones abscise usually before winter. shoots. shoots. Reproductive shoots abscise and vegetative vegetative shoots persist after flowering sea- Specific shoot orgamzatwn of Pmus son. son. Buds in the axils of scale-like prophylls ogawana are are not present or ， if present ， they do not de- Prunus ogawana is basically similar to velop. velop. other species of sec t. Pseudocerasus and it Group II [Prunus ogawana] was difficult to find any distinction between All All buds in the axils of leaves produce re- them except for the flowering of P. ogawana productive productive and mixed shoots (all shoots have at a juvenile stage. For this reason ，on the flowers). flowers). The buds in the axil of scale-like basis of similar mo 中hology in the juv~nile prophylls prophylls in P. ogawana often develop into stage ，Makino (1912) ，Ohwi (1952) and vegetative vegetative shoots. All reproductive shoots Sugimoto (1961) treated it as a form of P. 336 植物研究雑誌第76 巻第6号 平成13 年12 月 jamasakura. jamasakura. Our study ，however ， revealed of P. persica indicated that it has the same that that P. ogawana is far different from the pattem (Guo et a1. 1992 ， Kervella et a1. other other species in sec t. Pseudocerasus in shoot 1995). Taxonomic studies based on morpho- organization organization (Table 2). logy have classified these three species into We consider P. ogawana to show specific three different subgenera of Prunus s. 1.， but shoot shoot organization because al1 winter buds the phylogenic analysis using DNA se- grow into shoots with flowers. Winter buds quences shows their close relationship. Our of of other species of sec t. Pseudocerasus study corroborates the results of that

usually usually develop into shoots with no flowers phylogenic analysis ， but the number of spe 閏 and and shoots with some flowers and no leaves cies we analyzed is too few. Further analyses (reproductive) (reproductive) and some with just leaves of shoot organization in additional species in (vegetative); (vegetative); the vegetative shoot is photo- the subgenera Prunus ， Amygdalus and synthetic synthetic and contributes to vegetative Cerasus sec t. Microcerasus 紅 e needed. growth. growth. In P. ogawana ，all winter buds de- velop velop into shoots with flowers. If all shoots Shoot 01 苫anization of Prunus grayana had had no leaves ， as in the reproductive shoots Prunus grayana shows distinct shoot or- of of other species of sec t. Pseudocerasus ， P. ganization. The most remarkable feature is ogawana would not develop leayes and the abscission of all shoots except the termi- could could not. photosynthesize. It is understand- nal ones. In other species ，all shoots with able ，therefore ， that P. ogawana develops leaves persist and the buds in the axils of leaves leaves on reproductive shoots (= mixed their leaves develop into winter buds. In P. shoots) shoots) and that buds in the axils of scale- grayana ，we observed that the buds in the like like prophylls develop into leafy shoots for axils of the leaves also expand and develop vegetative vegetative growth. some leaf primordia ， but all shoots with those those axillary buds abscise by the end of the Shoot Shoot organization of Group 1 -genus growing season. In other words ， the develop- Cerasus Cerasus Group ment of buds in the leafaxils of non-terminal Prunus Prunus is sometimes divided into several shoots appe 紅 s to be of no use to the plan t. genera genera (Komarov 1971 ，Yu et a1. 1986 ，Ohba It is also a distinct character of P. grayana 1992). 1992). Ohba (1992) united and raised subge- to develop mixed shoots as in P. ogawana ， nus nus Cerasus sections Pseudocerasus and but ， the features of development are not the Phyllomahaleb Phyllomahaleb to the genus Cerasus for the same. While P. ogawana develops mixed Japanese Japanese species. A recent phylogenetic shoots because of flowering in all shoots ， P. analysis analysis using DNA sequences also showed grayana develops vegetative shoots as well. the the monophyly of Cerasus in the sense of We therefore consider that there may be Ohba (1 992) (Lee and Wen 2001). In our some developmental differences in the for- study ，all species of subgenus Cerasus sec- mation process of mixed shoots between P. tions tions Pseudocerasus ， except P. ogawana ， and grayana and P. ogawana. Phyllomahaleb ，紅e in Group 1. Further Further study Shoot Shoot organization of Group III -Prunus The present study indicates the specificity mume and P. glandulosa of shoot organization of P. ogawana. It is es- Our study showed that P. mume and P. pecially important that P. ogawan αdevelops glandulosa glandulosa can be categorized into one cate- leaves on its mixed shoots since the develop- gory gory with the same shoot organization pat- ment of both flowers and leaves on the same tem. tem. Previous studies on shoot organization shoot has never been observed in other spe- December December 2001 Journal of Japanese Botany Vo l. 76 No. 6 337 cies cies of genus Cerasus in the sense of Ohba mation in Prunus yedoensis Matsum. J. Jap. Soc. (1992). (1992). The leaf development process in this Hort. Sci. 58: 472 -4 73. species species is expected to be different from other Guo Z. ， Goi M. ，Tanaka M. and Chujo T. 1992. Mo 中hological studies on the bud formation in species species in subgenus Cerasus ， which will be Prunus persica Batsch. Mem. Fac. Agric. Kagawa examined examined and discussed in a forthcoming Univ.44: 167-173. study. study. Kervella J. ， Pages L. and Genard M. 1995. Growth Our results also indicate that shoot organi- context and fate ofaxillary meristems of young zation zation might be an important taxonomic fea- peach trees. lnfluence of p訂 ent shoot growth char- acteristic acteristic of emergence date. Ann. Bo t. (Oxford). ture ture for reevaluating Prunus s. 1.， since 76: 559-567. phylogenetic phylogenetic studies using DNA sequences Komarov V. L. 1971 Rosaceae: Rosideae ，Amygdaloi- have have basically agreed with our groupings of deae. Flora URSS 10: 1-512. English translation. species species based on shoot organization. Smithonian lnstitution ，Washington ，DC. Extensive Extensive observation of shoot organization Kubota H. 1993. Prunus ogawana and Prunus on additional species is needed. verecunda forma norioi. Kyoto Engei. 88: 7ー11. Lauri Lauri P. 199 1. Donnees sur l'evoltion de la ramifica- Shoot Shoot organization in P. grayana also tion et de la floraison du pecher Prunus persica (L) needs needs further analysis. From an evolutionary Batsch. au cours de sa croissance. Ann. Sci. Na t.， point point of view ， shoot abscission following Bo t. 11: 95-103. bud growth in this species is very inefficien t. Lee S. and Wen 1. 200 1. A phylogenetic analysis of It It is difficult to understand how or why this Prunus and the Amygdaloideae (Rosaceae) using ITS ITS sequences of nuclear ribosomal DN A. Amer. 1. pattern pattern developed. Further ecological and Bo t. 88: 150-160. evolutionary evolutionary studies may provide an answe r. Makino T. 1892. Notes on Japenese . Bo t. Mag. Tokyo 16: 45-56 [mainly 52]. We thank Tama Forest Science Garden 一一一 1906. Observations on the flora of Japan. Bo t. and and M r. T. Katsuki for providing of materi- Mag. Tokyo 20: 37 -4 5 [mainly 44-4 5]. als. als. We also thank M r. T. Kurita and M r. T. 一一一 1908. Observations on the flora of Japan. Bo t. Mag. Tokyo 22: 93-102 [mainly 98-99]. 1wayama for providing of materials and the 一一一 1912. Observations on the flora of Japan. Bo t. advice advice how to propagate P. ogawana. We Mag. Tokyo 26: 172-184 [mainly 176-177]. acknowledge acknowledge the general advice of Professor 一一一 1928. A contribution to the knowledge of the H. H. Ohba and Ms. A. Shimizu ， the University Flora of Japan. J. Jpn. Bo t. 5: 11-14 [mainly 11- Museum of the University of Tokyo. Our 12]. Ohba H. 1989. Prunus. In: Satake Y. ， Hara H. ， Watari thanks thanks also go to D r. David E. Boufford ， S. and Tominari T. ，Wild Fl owers of Japan ，Woody Harverd Harverd University Herbaria for checking Plants 1: 18 6- 198. Heibonsha Ltd. ， Tokyo. the the English text and conten t. 一一一 1992. J apanese trees under the genus This This study was partly supported by The Cerasus (Rosaceae). J. Jpn. Bo t. 67: 27 6- 281 ， New Technology Development Foundation ， Ohwi J. 1952. A juvenile form of Prunus verecunda Koehne. Koehne. J. Jpn. Bo t. 27: 148. the the Makino Botanical Garden ， Kochi Rehder Rehder A. 1940. A manual of cultivated trees and Prefecture ， and the public office of Sakawa- shurbs hardy in North America exclusive of the cho cho in Kochi Prefecture. subtropical and warmer temprate regions ， 2nd ed. Macmillan ，New Y or k. References References Sugimoto 1. 196 1. New Keys of Japanese Trees. Rokugatsusha Rokugatsusha Ltd. ， Osaka. Ghora C. and Panigrahi G. 1995. The family Rosaceae Yu T. ーT. ，Lu L.- T. ，Ku T.- C.， Li c.-L. and Chen S.-X. in in lndia ， 2. Bishen Sigh Mahendra Pal Singh ， 1986. 1986. Rosaceae (3) ， Amygdaloideae. Fl ora Dehra Dehra Dun. Reipublicae Reipublicae Popularis Sinicae ， 38. Science Press ， Goi M. ，Guo Z. and Tanaka M. 1989. Studies on the Beijing. Beijing. bud formation in temperate ornamental tree and s耐ubs. 2. Seasonal investigations on the bud for- 338 338 植物研究雑誌第76 巻第6号 平成13 年12 月

岩元明敏a，宮崎慶子b ，邑田 仁c .パラ科サクラ 属のシュート構成の多様性およびワカキノサクラ の特異性について 番目のグループにはウメ及びニワザクラが， 4 番 本研究ではパラ科サクラ属 (Prunus) 植物のシュー 目のグループにはウワミズザクラがそれぞれ含ま ト構成の多様性を明らかにするため，日本に自生 れた.ワカキノサクラは他のサクラ節植物とは異 する種を中心にサクラ属 13 種(サクラ亜属サクラ なるグループに属し，全てのシュートに花をつけ 節10 種， ミヤマザクラ節 1 種，ユスラウメ節 1 種， る，混成芽を持つ，前出葉肢芽が展開するなどシュー スモモ亜属 1 種，ウワミズサクラ亜属 1 種)につ ト構成に大きな特異性を持つことが分かつた.ま いて年間を通じた観察を行った.この結果，対象 た，グループ分けが基本的にサクラ属についての とした 13 種は (1) 冬芽成長 (2) 冬芽の鱗片化し 分子系統解析と一致することから，シュート構成 た前出葉肢芽の発達・伸長 (3) 枝の脱落性とい がサクラ属内の系統関係を反映している可能性も う3 つのシュート構成の特徴に注目することで， 示唆された. 明確に 4 つのグループに分けられ，多様性が確認 (a 東京大学総合研究博物館，

された.最初のグループには ワカキノサクラを b東京都立大学牧野標本館 除くサクラ亜属サクラ節とミヤマザクラ節の 9 種 現所属:慶応義塾高校講師，

が， 2 番目のグループにはワカキノサクラが， 3 c東京大学大学院理学系研究科附属植物園)