〔植探報Vol. 23 : 55 ～ 61，2007〕

長野県・山梨県におけるリンゴ属の探索・収集
池谷 祐幸・間瀬 誠子・佐藤 義彦
農業・食品産業技術総合研究機構・果樹研究所・研究支援センター・遺伝資源室

Exploration and Collection of Malus Genetic Resources in
Nagano and Yamanashi Prefectures.
Hiroyuki IKETANI, Nobuko MASE and Yoshihiko SATO
Laboratory of Genetic Resources , Research Support Center , National Institute of Fruit
Tree Science , National Agriculture and Food Research Organization .
2-1 Fujimoto, Tsukuba, 305-8615, Japan.

Summary
Wild genetic resources from indigenous populations of apple species in Nagano
and Yamanashi Prefectures were examined and collected. A total of 29 accessions of apple
genetic resources, including 15 from Malus baccata var. mandshurica and 14 from M.

toringo , as well as 1 from Pyrus ussuriensis var. hondoensis were collected. The former
two species were sympatrically distributed in four of the six areas surveyed in this study.
Hybridization or introgression between them is suspected in these areas.

KEY WORDS: genetic resources, apple, Malus , Nagano, Yamanashi, Chubu
Introduction
There are four species of Malus (Rosaceae, Maloideae) that grow wild in Japan, as well
as several cultivated species that originated from the Asian continent in ancient times or later,or were introduced from the Occident in modern times. These species have been explored byforeign and Japanese horticulturalists and botanists since the middle of the 19th century. As aresult, several genetic resources or botanical living collections reported to have been introduced
from Japan are now preserved in many facilities around the world. Unfortunately, there is little
or no detailed collecting data on these materials, even for the plants deposited in the NIAS
Genebank.
In addition, the Japanese provenance of some of these cultivated Malus plants is doubtful
due to morphological differences with both wild and cultivated species found in Japan. An- 55 -

extreme example is Malus floribunda . This species has been well utilized for ornamentals
and for the breeding of apple scab resistance and was reported to have originated in Japan.
However, neither wild nor cultivated plants of this Malus species have been identified in Japan.
Thus, the origin of apple scab resistance of this species is still unknown.
We have studied the taxonomy and distribution of Japanese Malus species1), 2), and3)started to explore and collect genetic resources from wild populations , in order to construct
core collections of them and for other purposes. This year we are surveying Nagano andYamanashi Prefectures in the Chubu region, an area which marks the western and southernboundaries of the distribution of Malus baccata (L.) Borkh. var. mandshurica (Maxim.)
C.K.Schneid. (“Ezo-no-koringo” in Japanese) in Japan. This species is distributed in isolated
mountain pockets of this area since it grows wild in upper temperate zones (about 1,000 - 2,000m height above sea level). We are also planning to collect M. toringo (Siebold) Siebold ex Vriese(“Zumi” or “Mitsuba-kaidou” in Japanese), which grows in similar habitats as the former species
but is more common.
Methods
The first field survey was conducted in May and June of 2006 to discover wild trees
in their native habitats, and to collect flower and fresh leaf samples for morphological andmolecular studies. The second field survey was performed in September and October of 2006
to acquire scions for genetic resource collections. Voucher herbarium specimens were alsocollected in both surveys. Based on the information obtained from the preliminary field survey
and from herbarium specimens preserved in various facilities in Japan, we traveled to the Fuji
Mountains, Nyuugasa Mountains, Yatsugatake Mountains, Chichibu Mountains, Karuizawa High
Plateau and Shiga-Kougen High Plateau to survey as much of the distribution area of M. baccata
as possible.
Results
A total of 29 accessions of apple genetic resources were collected. Fifteen individualsof Malus baccata var. mandshurica were collected from four different mountains and 14 of M.

toringo were collected from six mountains. We also found and collected one Pyrus ussuriensis
var. hondoensis sample in the Nyuugasa Mountains, which we had not surveyed during the4)

exploitation of Pyrus genetic resources in 2004 .
The following are brief descriptions of the habitats of the collection sites.
1) Shiga-Kougen High Plateau
This plateau is situated from 1,500 - 1,700 m in elevation. Both species prefer moist places
around ponds or moors so we especially searched such places. Malus toringo was more common
and was found other ponds and moors in addition to our collection.
On the other hand, M. baccata var. mandshurica was very rare. Since this area is one of themost artificially exploited places in the present distribution area of this species in the Chubu
region, this rarity is perhaps due to an artificially-induced decrease. However, considering that2)

this is also the northern limit of the species’ present distribution in this region , the population- 56 -

1
Nagano●□2▲●

Mt. Asama-yama
4●
●

●

5

6
□

3●

□

Tokyo

Kôfu
7

●
▲

□

Yokohama

Mt. Fuji-san

Fig. 1. Collection sites of Malus genetic resources in Nagano and Yamanashi Prefectures.

structure may possibly be fluctuated by the bottleneck effect if this paucity of individuals in the
population is a natural phenomenon and this plant has occurred since geological age.
We also discovered a small population of M. baccata var. mandshurica at Nozori-ko Lake,
about 12 km east of this plateau.
2) Karuizawa High Plateau
We collected two plants of Malus toringo at the border between Nagano and Gunma
Prefectures. This species was common in this area from about 800 m to 1,700m in elevation.
Here it grew in secondary deciduous forests dominated by Quercus cripula or Q. serrata ,especially at forest margins. At one time, there had been extensive wetlands in the southernpart of Karuizawa. But almost all of them were completely destroyed to develop leisure facilities.
Some M. toringo trees were kept at these leisure facilities as ornamental trees.
3) Nyuugasa Mountains
Two moors, Oo-awara Moor and Nyuugasa Moor, are found in this area. We collectedmaterials from the former moor, where about 50 individuals of Malus baccata var. mandshurica
and a greater number of M. toringo were found. Both species were also found outside of themoors. M. toringo was distributed continuously in secondary forests from low elevation areas(about 1,000 m a.s.l.), while Malus baccata var. mandshurica grew only in areas surrounding themoors.

M. baccata var. mandshurica also occurs south of here, but the number of individuals is very
5)

limited . The population here is perhaps the southernmost one which contains a stable numberof individuals.
We also collected one sample of Pyrus ussuriensis var. hondoensis , the first time we had- 57 -

collected this material since we did not survey this area in our previous exploration for this4)

tree . This area is perhaps the only remaining indigenous habitat of this plant on the western
6)

side of the Itoigawa-Shizuoka Tectonic Line .
4) Yatsugatake Mountains
The number of Malus baccata var. mandshurica in this area is undoubtedly the largest in the
Chubu region. We can find this species in its preferred habitat from 1,300 m to 1,800 m inelevation throughout this area. We collected materials at a valley in the upper reaches of the
Shibu-kawa River. The south bank of this river consists of gentle slopes, which might have beencreated by pyroclastic flow from the Yatsugatake Volcano. Some places along this bank havebecome wetlands and preferred habitat for two Malus species.
5) Chichibu Mountains
We have already revealed that Malus baccata var. mandshurica is distributed in the areas
2)of Nagano and Yamanashi Prefectures of the Chichibu Mountains . However, since the datefrom the preliminary survey and the herbarium specimens indicated that there may be only alimited number of individuals on the south side (Yamanashi Pref.) of the Mountains, we decided
to survey the northwest side (Nagano Pref.). Here, M. toringo grew from lower elevations (lessthan 1,000 m) up to 1,600 m. Malus baccata var. mandshurica was generally found at higher
elevations (1,400 m or more), and was most common in riparian deciduous forests in the upper
reaches of the Chikuma-gawa River.
The microtopography of this locality is similar to that of the Shibu-kawa River Valley in the
Yatsugatake Mountains. Gentle slopes and wetlands occur throughout the area. It should be
noted that this terrain had been created by non-volcanic geographical processes.
6) Fuji Mountains
In this area, only Malus toringo occurs but it is very common. We surveyed from thenorthwest slope of Mikuni Touge Pass to the eastern shore of Yamanakako Lake.
7) Overview
Both species occurred in four of the six areas surveyed in this study. At the Chikumagawa River site in the Chichibu Mountains, the two species grew separate from one another,but in the Shiga High Plateau, Nyuugasa Mountains and Yatsugatake Mountains, they grew
sympatrically. Hybridization or introgression between them is suspected in these latter areas
because these two species have almost no interspecific physiological mating barriers. Some of
the bastard genetic resources and cultivated plants of the ostensibly Japanese provenance may
possibly be of hybrid origin.
We are planning to investigate the origin and analyze the molecular phylogeny andpopulation genetic structure of Japanese Malus populations using the materials collected inthis study. We expect the results will come in useful for unlocking the mystery of the origin ofMalus genetic resources as well as for revealing their genetic diversity.

- 58 -

Acknowledgements
We are grateful to Dr. M. Aizawa of Utsunomiya University for providing valuable
information about the distribution of Malus baccata var. mandshurica. We would also liketo thank the following facilities for granting us permission to investigate and collect plantmaterials: Wago-kai Foundation; Shiga Kougen Ranger Office, Ministry of Environment; Toshin
District Forest Office, Forestry Agency, MAFF; Nanshin District Forest Office, Forestry Agency,
MAFF.
References
1) Iketani H. and H. Ohashi (2001) Malus . in: Iwatsuki K. et al . (eds.) Flora of Japan IIb.
Angiospermae Dicotyledoneae Archichlamydeae (b): 120-123. Kodansha, Tokyo.
2) Iketani H. (2004) Rediscovery of Malus baccata var. mandshurica at Nikko and thereexamination of its taxonomy. Bunrui 4: 125-136. (in Japanese)3) Iketani H., M. Mase and Y. Sato (2006) Exploration and Collection of Pyrus and Malus
genetics resources in Northern Tohoku region. Annual Report on Exploration and Introductionof Plant Genetic Resources 22: 13-21. (in Japanese)4) Iketani H., M. Mase and Y. Sato (2005) Exploration and Collection of Pyrus ussuriensis
var. hondoensis in Yamanashi and Nagano Prefectures. Annual Report on Exploration andIntroduction of Plant Genetic Resources 21: 37-43. (in Japanese)5) M. Aizawa (personal communication).
6) Iketani H. and H. Ohashi (2003) Taxonomy and distribution of Japanese populations of Pyrus

ussuriensis Maxim . (Rosaceae). J. Jpn. Bot. 78: 119-134.
和文摘要
長野県と山梨県において，リンゴ属野生遺伝資源の探索・収集を行い，エゾノコリンゴ１５点とズミ１４点を収集した．この他にアオナシ１点も収集した．調査した６地域のうち４地域では，エゾノコリンゴとズミは同所的に生育しており，雑種形成を行っている可能性が疑われた．

- 59 -

Table 1. List of Malus and Pyrus genetic resources collected in Nagano and Yamanashi Prefectures.
Collection Name

Species

Date

Place

Municipality

Pref.

Locality Longitude(E) Latitude(N)
No.(Fig.1) (ddd-mm-ss) (dd-mm-ss)

Alt.
(m)

Field No.

- 60 -NAGANO MALUS COL.NO.2006-1

Malus baccata var. mandshurica

9/10/2006 around Ichi-numa Pond, Hirao

Yamanouchi-machi Nagano

1

138-28-47

36-43-71410 Sg-b14

NAGANO MALUS COL.NO.2006-2

Malus toringo

9/10/2006 around Biwa-ike Pond, Hirao

Yamanouchi-machi Nagano

1

138-28-57

36-43-07

1400 Sg-t23

NAGANO MALUS COL.NO.2006-3

Malus toringo

9/10/2006 around Biwa-ike Pond, Hirao

Yamanouchi-machi Nagano

1

138-28-57

36-43-07

1400 Sg-t25

NAGANO MALUS COL.NO.2006-4

Malus baccata var. mandshurica

9/10/2006 around Ichi-numa Pond, Hirao

Yamanouchi-machi Nagano

1

138-28-47

36-43-71410 Sg-b13

NAGANO MALUS COL.NO.2006-5

Malus toringo

9/11/2006 in a moor near of Shizen-kyouiku-en, Hirao Yamanouchi-machi Nagano

1

138-29-39

36-42-43

1560 Sg-t7

NAGANO MALUS COL.NO.2006-6

Malus baccata var. mandshurica

9/11/2006 near Sachino-yu, Hidadoko

Yamanouchi-machi Nagano

1

138-29-23

36-41-40

1640 Sg-b3

NAGANO MALUS COL.NO.2006-7

Malus baccata var. mandshurica

9/11/2006 near Sachino-yu, Hidadoko

Yamanouchi-machi Nagano

1

138-29-05

36-42-14

1560 Sg-b7

NAGANO MALUS COL.NO.2006-8

Malus toringo

9/12/2006 near the border of Gunnma Pref.

Karuizawa-machi

Nagano2138-34-15

36-25-101370 Kr-t17

NAGANO MALUS COL.NO.2006-9

Malus toringo

9/12/2006 near the border of Gunnma Pref.

Karuizawa-machi

Nagano2138-35-11

36-25-131350 Kr-t23

NAGANO MALUS COL.NO.2006-10

Malus baccata var. mandshurica

10/3/2006 in Oo-araha Moor

Hase-mura

Nagano3138-10-57

35-53-07

1815 Ng-b5

NAGANO MALUS COL.NO.2006-11

Malus baccata var. mandshurica

10/3/2006 east of Oo-araha Moor

Fujimi-machi

Nagano3138-10-57

35-53-13

1820 Ng-b11

NAGANO MALUS COL.NO.2006-12

Malus baccata var. mandshurica

10/3/2006 in Oo-araha Moor

Hase-mura

Nagano3138-10-57

35-53-07

1815 Ng-b22

NAGANO MALUS COL.NO.2006-13

Malus baccata var. mandshurica

10/3/2006 north of Oo-araha Moor

Hase-mura

Nagano3138-10-42

35-53-21

1825 Ng-b61

NAGANO MALUS COL.NO.2006-14

Malus toringo

10/3/2006 in Oo-araha Moor

Hase-mura

Nagano3138-10-57

35-53-07

1815 Ng-t18

NAGANO MALUS COL.NO.2006-15

Malus toringo

10/3/2006 in Oo-araha Moor

Hase-mura

Nagano3138-10-57

35-53-07

1815 Ng-t19

NAGANO MALUS COL.NO.2006-16

Malus baccata var. mandshurica

10/4/2006 around upstream of Shibu-kawa River

Chino-shi

Nagano4138-18-00

36-02-02

1645 Ts-b105

NAGANO MALUS COL.NO.2006-17

Malus baccata var. mandshurica

10/4/2006 around upstream of Shibu-kawa River

Chino-shi

Nagano4138-19-14

36-01-59

1780 Ts-b201

NAGANO MALUS COL.NO.2006-18

Malus baccata var. mandshurica

10/4/2006 around upstream of Shibu-kawa River

Chino-shi

Nagano4138-18-26

36-02-02

1675 Ts-b202

NAGANO MALUS COL.NO.2006-19

Malus toringo

10/4/2006 around upstream of Shibu-kawa River

Chino-shi

Nagano4138-18-26

36-02-02

1675 Ts-t201

NAGANO MALUS COL.NO.2006-20

Malus toringo

10/4/2006 around upstream of Shibu-kawa River

Chino-shi

Nagano4138-18-09

36-02-01

1655 Ts-t209

NAGANO MALUS COL.NO.2006-21

Malus toringo

10/4/2006 around upstream of Shibu-kawa River

Chino-shi

Nagano4138-18-09

36-02-01

1655 Ts-t210

NAGANO MALUS COL.NO.2006-22

Malus baccata var. mandshurica

10/5/2006 around upstream of Chikuma-gawa River

Kawamami-mura

Nagano5138-43-05

35-56-57

1450 Kw-b4

NAGANO MALUS COL.NO.2006-23

Malus baccata var. mandshurica

10/5/2006 around upstream of Chikuma-gawa River

Kawamami-mura

Nagano5138-42-54

35-57-01480 Kw-b6

NAGANO MALUS COL.NO.2006-24

Malus baccata var. mandshurica

10/5/2006 around upstream of Chikuma-gawa River

Kawamami-mura

Nagano5138-42-40

35-57-15

1460 Kw-b10

NAGANO MALUS COL.NO.2006-25

Malus baccata var. mandshurica

10/5/2006 around upstream of Chikuma-gawa River

Kawamami-mura

Nagano5138-42-33

35-57-18

1450 Kw-b18

NAGANO MALUS COL.NO.2006-26

Malus toringo

10/5/2006 Megurime-daira

Kawamami-mura

Nagano6138-38-51

35-54-59

1520 Kw-t202

NAGANO MALUS COL.NO.2006-27

Malus toringo

10/5/2006 Megurime-daira

Kawamami-mura

Nagano6138-38-37

35-54-42

1580 Kw-t205

YAMANASHI MALUS COL.NO.2006-1 Malus toringo

10/7/2006 the top of Mikuni-touge Pass

Yamanakako-mura Yamanashi

7138-54-56

35-24-191170 Ymk-t1

YAMANASHI MALUS COL.NO.2006-2 Malus toringo

10/7/2006 eastshore of Yamanaka-ko Lake

Yamanakako-mura Yamanashi

7138-53-55

35-25-41

980

Fujimi-machi

3138-10-29

35-53-37

1835 Ng-1

NAGANO PYRUS COL.NO.2006-1

Pyrus ussuriensis var. hondoensis 10/4/2006 near Kubikiri-shimizu

NaganoYmk-t18

Photo 1. An indigenous habitat of Malus baccata
var. mandshurica and M. toringo . Deciduous
shrub vegetation dominated by these two species
has developed at the margin of a high moor. Ooawara Moor, Hase-mura, Nagano Pref. (Nyuugasa
Mountains).

Photo 2 Infructescence of Malus baccata
var. mandshurica . Near Sachino-yu, Hiradoko,
Yamanouchi-machi, Nagano Pref. (Shiga Kougen
High Plateau).

Photo 3 Infructescence of Malus toringo(red fruit type). In Oo-araha Moor, Hase-mura,
Nagano Pref. (Nyuugasa Mountains).

Photo 4. Infructescence of Malus toringo (yellow
fruit type). Around the upper reaches of the Shibukawa River, Chino-shi, Nagano Pref. (Yatsugatake
Mountains).

- 61 -