IInntet err na
nattiioonnaall C
Ceenntteerr ffoorr RReesseeaarrchch andandEdEduuca
c attiioonn iinn Ag
Agrriiccululttuurree((IICCRREEAA),), Nago
Nagoyaya U
Univeniversitrsityy

Res e a r ch acti v i t i es
■Research on improving rice productivity in the unfavorable environments of the tropics
To feed an ever-growing global population, it is important to increase food production and secure a stable food supply
even in an environment not suited for agricultural production. In particular, demand for rice, which is a staple food for overhalf of the world's population, is expected to keep increasing in the coming decades, which makes it imperative to increaserice production. Rice ﬁelds in the tropical regions in Asia and Africa are faced with various environmental stresses that cancause a reduction in rice yields. At our research bases in Kenya, Indonesia, and Cambodia, we are undertaking the following
activities with the goal of increasing rice production in unfavorable environments: evaluation of factors inhibiting riceproductivity, assessment of adaptability of local rice varieties to stress, genetic analysis, genetic improvement of rice, anddevelopment of eﬀective cultivation techniques.

1) Genetic improvement of rice to secure stable rice production in unfavorable environments

03

In addition to the conventional cross breeding and mutation breeding technologies, novel
breeding techniques, such as quantitative trait locus (QTL) analysis (which identiﬁes QTLs
associated with stress tolerance) and marker-assisted selection (MAS) (which can quickly andGrowth inhibition of rice underaccurately identify the presence of a speciﬁc quantitative trait locus) are now available to breed
drought stress conditions
improved rice varieties with a greater eﬃciency, thanks to the recent
research advancements in the ﬁeld of agricultural sciences. Noveltechniques, such as next generation sequencing (NGS) (which quickly andinexpensively provides genome-wide genetic information on livingorganisms) and new plant breeding techniques (NBT) (new approach togenome editing) have also been developed. We are using thesetechnologies to achieve genetic improvement of rice with the goal of
Research activities for development of new rice varieties
with tolerance to environmental stresses
securing stable rice production in unfavorable environments.

2) Development of cultivation techniques to increase rice productivity in unfavorable environments in Africa
Rice yields in Africa have remained low due to various biotic and abiotic stresses including drought, cold temperatures inhighlands, high salinity, low-fertility soils, rice blast disease, and rice yellow mottle virus. To increase rice yields in suchunfavorable environments, it is necessary to genetically improve rice crops to enhance adaptability to unfavorable
conditions. The stress tolerance and crop productivity observed in the actual farm ﬁelds, however, are not only determinedby the genetic traits of crop varieties but also aﬀected by cultivation environments and the cultivation management
strategies used.
Through collaboration with our research colleagues, we are carrying out ﬁeld surveys to evaluate factors inhibiting riceproductivity. Furthermore, we are growing rice lines into which we have incorporated the QTLs associated with improved
adaptability to environmental stresses and improved rice yields. In addition, we are carrying out rice cultivation trials in acontrolled artiﬁcial environment as well as in the actual farm ﬁelds to identify both the rice traits suitable for the cultivation
environments in Africa and the QTLs that are associated with these traits, and to understand the cultivation conditions thatenable the incorporated QTLs to function eﬀectively.

・Identiﬁcation of factors

inhibiting rice productivity

・Evaluation of environmental
stresses adaptability in rice

・DNA analysis
・Genetic improvement of rice・Development of cultivation

Genotype（G）

technologies

Conducting cultivation trials in Kenya

Interactionanalysis

Improvement of riceproductivity inunfavorableenvironments

Environment（E）

ManagementTechnology（M）
Research under controlled environments
in Nagoya UniversityInt
Inteernat
rnatioional
nal CCeent
nteerr ffoorr ReResesearcharch andandEEdduucat
cat ioionn inin Agricult
Agricultureure(IC(ICREA),REA), Nago
Nagoyaya U
Univeniversitrsityy3) Development of ﬂood-adaptive rice cultivation technology
Since the late 1990s, the world has witnessed a rapid increase in major ﬂooding events. Flood management approaches
employed in Asian regions, which involve the use of newly developed or improved irrigation techniques, are not suﬃcient toavoid the damage of devastating ﬂoods that hit these regions, where vulnerability of crop cultivation to ﬂoods still poses aserious problem. In ﬂood-prone regions, rice must be planted during the deepwater ﬂood
phase of the rainy season in order to prevent rice crops from sustaining damage fromdryness during the late stage of growth. Inevitably, this puts the rice crops at risk of
ﬂood damage during the early stage of growth.
In addition to reevaluating the double-transplanting technique that has been used in thelow-lying swamps along the east coast of Sumatra and the west coast of Peninsular
Malaysia, we have been investigating the growth response of the locally grown rice
Uprooting of seedlings for thevarieties to ﬂoods to identify the traits associated with ﬂood adaptation of rice varieties
ﬁrst transplantingthat are grown in several diﬀerent regions with varying
water depth levels and varying periods of deepwater
ﬂood phase. Our goal here is to ensure stable productionof rice crops in ﬂood-prone regions through the use of
traditional techniques, and to improve cultivation
technology by using fertility management strategies that
not only help mitigate the harmful eﬀects ofRice seedlings growing on a raft for 2 weeks
First transplanting (second transplanting
submergence stress but also facilitate recovery fromprior to the ﬁrst transplanting
will be done after 20 days)
ﬂood damage.

■International Sago Palm Project for food security improvement
Agricultural production must increase by 70% globally to feed the world's population that is projected to reach 9 billion by
2050. Climate change and diminishing underground resources (including oil) also pose serious challenges to food security,
and we need to focus on how we can enhance agricultural production/productivity in a sustainable way while minimizing
post-harvest biomass losses. In view of this, our research group focused its attention on sago palms that grow naturally inSoutheast Asian and South Paciﬁc regions.
This palm adapts well to infertile/acid soils or brackish-water regions that are generally unsuited for crop cultivation.
Furthermore, one palm can yield approximately 300 kg of starch. Sago is a staple food for local residents, and is used as aningredient in biscuits, noodles, and other food products. Although it is not generally known, sago
ﬂour is used to knead buckwheat noodles and udon noodles in Japan. As an ingredient of choicefor people with food allergies, sago has recently been used in a number of cosmetics as well.
With only 10% of the wild and semi-cultivated sago palm stands believed to be harvested for use
today, there is much room left for further exploitation of this economic plant.
In our laboratory, we are investigating the mechanism through which sago palms adapt tosaline and acidic soils. Furthermore, we are carrying out ﬁeld surveys to monitor the growth ofsago palms to inform our eﬀorts to develop an eﬀective cultivation management strategy thatenables stable growth of sago palms. We are also undertaking the following activities as part ofSpineless type sago palma joint international research project: use remote sensing to estimate the area of the land on(East sepic, PNG)
which sago palms are growing and to identify areas
suitable for growing sago palms, develop technology tomake sweeteners from the residue from sago starch
extraction, and estimate the socioeconomic impact of
the new technology.
Measurement of physiological parametersat the pilot farm of sago palm in Southeast
Sulawesi, Indonesia

Sago palm ﬁeld in Southeast
Sulawesi, Indonesia04