Ⅲ-4. Radiation Chemistry & Biology

RIKEN Accel. Prog. Rep. 52 (2019)

Eﬀect of heavy ion beam irradiation on germination and mutation
rate in local Toraja rice
R. Sjahril,∗1 M. Riadi,∗1 Raﬁuddin,∗1 T. Sato,∗2,∗3 K. Toriyama,∗2 Y. Hayashi,∗3 T. Abe,∗3 andA. R. Trisnawaty∗1
Tana Toraja is one of the areas in South Sulawesi
that has wide local rice germplasm diversity. Basedon the results of a survey of local rice in the TanaToraja district, Suhardi et al. found approximately
29 local varieties of Toraja rice, each of which has
exotic characteristics such as brown rice, red, aromatic and glutinous.1) The local rice cultivars have
many unique traits, for example black and red rice.
These colored rice cultivars are in the spotlight as foodwith health-promoting beneﬁts because these pigments
found in them have an antioxidative eﬀect.2) However,improved rice cultivars are expanded in this area. Most
farmers grow no native rice cultivar because the yieldof these cultivars is lower than the improved cultivars
and have long maturity during 5–6 months (Fig. 1). Itis feared this will result in a lack of local rice cultivars
as germplasm materials. Our research aims to improve
the productivity of local cultivars with unique trait byheavy-ion beam irradiation. In this study, we evaluated seed germination as a result of irradiation using
ion beam in two varieties of Toraja local rice.
Pare Ambo and Pare Lea are black and red rice cultivar (Oryza sativa L.) in Tana Toraja, respectively(Fig. 2). Dry seeds packed in a plastic case were irradiated with Ar (309 keV/µm) and C (30 keV/µm)
in RI-beam factory, RIKEN Nishina Center, Japan.
The doses of Argon-ion and Carbon-ion were 10 and150 Gy, respectively.3,4)
Each grain from one panicle for each M1 plant wasgerminated in one line method on a 15 cm Petri dishand transplanted into small plastic bags. The germiFig. 1. Local red rice “Parelea” has a long culm tending
to lodge.

Table 1. Germination rate (%) on M1 and M2 seeds inTana Toraja rice cultivars Pare Ambo and Pare Lea.
BeforeIrradiation

Cultivar
Pare Ambo
Pare Lea8598M1

M2Irradiation Ion

Irradiation Ion

CarbonArgon

Carbon

Argon

54
97

55
98

85
93

90
94

Table 2. Number of plants undergoing albino mutation inTana Toraja rice cultivars Pare Ambo and Pare Lea.
Ion

M2 plants

AlbinoMutation Rate

Carbon Pare Ambo

(No.)
414

(No.)
8(%)
1.9

Pare Lea

1619

46

2.8

Pare Ambo
Pare Lea

901034

122

1.1
2.1

Argon

Cultivarnation percentages of seeds used before being irradiated are 85% and 98% in Pare Ambo and Pare Lea,
respectively (Table 1). Ion beam irradiation reducedthe germination percentage of Pare Ambo by approximately 30%. However, the germination percentage
of Pare Lea after irradiation was approximately thesame as before irradiation. M1 seeds of Pare Ambo
and Pare Lea irradiated with Argon-ion produced better seedling growths than Carbon-ion.
Further M2 seed germination shows uniqueness insome seedlings, such as lighter leaf color, albinism andwrinkled leaf, which could prove to be potential mutant
lines in tested M2 lines seed. Chlorophyll mutation inM2 plant was observed through the color of the leaves
ten days after sowing until the plant was transplanted
into the rice ﬁeld. The irradiation treatment with ion
beam also gives rise to chlorophyll mutations as seenin M2 of Pare Ambo and Pare Lea (Table 2). A higher
albino mutation rate was found in M2 population irradiated by carbon ion instead of argon ion in both
cultivars. The occurrence chlorophyll mutation occurring is a mutagenic eﬀect of carbon-ion beam, whichindicates that the treatment is eﬀective in the creationof genetic diversity in the M2 population.
ReferencesFig. 2. Pre Ambo (Blackrice) and Pare lea (red rice).
∗1
∗2
∗3

Hasanuddin University, Makassar, Indonesia
Tohoku University, Sendai, JapanRIKEN Nisina Center- 210 -1) Sahardi et al., Proc. of Nat. Sem. on Gen. Res. of Agr.
(2013), pp. 34–43.
2) Rahim et al., Int. J. Pharma. Phytochem. Res. 8, 771–776, (2016).
3) Y. Hayashi et al., RIKEN Accel. Prog. Rep. 51, 238 (2018).
4) Y. Hayashi et al., RIKEN Accel. Prog. Rep. 50, 27 (2017).