Developing japonica rice for the tropical areas
RDA Administrator Dr. Jae-Soo Kim (Korea
signed a Memorandum of Agreement on
the two institutions' continued collaboration
and its subsequent 2010 -11 work plan.
Introduction about japonica rice
Rice belongs
to the genus Oryza and
has two cultivated and 22 wild species. The cultivated species are Oryza
sativa and Oryza
glaberrima. Oryza
sativa is
grown all over the world while Oryza glaberrima has
been cultivated in West Africa for the last
~3500 years.
Rice is grown
under many different conditions and production systems, but submerged in water
is the most common method used worldwide. Rice is the only cereal crop that can
grow for long periods of time in standing water.
About 57% of
rice is grown on irrigated land, 25% on rainfed lowland, 10% on the uplands, 6%
in deepwater, and 2% in tidal wetlands .
Oryza sativa, commonly known as Asian rice, is the plant species most
commonly referred to in English as rice. Oryza sativa is
the cereal with
the smallest genome,
consisting of just 430 Mb across 12 chromosomes. It is renowned for being easy
to genetically modify, and is a model organism for cereal biology.
Oryza sativa contains two
major subspecies: the sticky, short grained japonica or sinica variety,
and the nonsticky, long-grained indica variety. Japonica varieties
are usually cultivated in dry fields, in temperate East Asia, upland areas of
Southeast Asia and high elevations in South Asia, while indica varieties
are mainly lowland rices, grown mostly submerged, throughout tropical Asia .
Mainstream archaeological evidence derived from
palaeoethnobotanical investigations indicate dry-land rice was introduced to Korea and Japan Korea
and Japan
Japanese rice not only be in Japan
Japanese rice is
commonly called for japonica rice
varieties that are now planted in the northeast China , Japan
and some areas in Europe and North America .
This is a short-grain variety of rice (Oryza sativa var. japonica) which
is characterized by its unique stickiness and texture.It also comes in a
variety called mochigome (sticky rice) which is used for making mochi. Rice begins as brown rice, genmai , which may then be polished by a machine (seimaiki), in which case
it is sold as ready-polished or white rice, hakumai .
Sprouted brown rice hatsuga genmai is also sold in smaller quantities. It has a softer texture than brown rice
and a pleasant fragrance, yet retains the health benefits of brown rice. Most
supermarkets in Japan
Rice is cultivated throughout Japan Hokkaidō , Japan Honshū , the Japanese mainland, varieties such as koshihikari are grown.
Rice is eaten in several ways in Japan
Rice is also used to make alcoholic drinks
like sake , rice
vinegar, snacks such as senbei ,
rice crackers, and agemochi.
Traditionally, rice was eaten at every
meal in Japan
Prepared rice is usually served from the
rice cooker into a chawan,
or rice bowl.
After cooking, rice may also be held in a
covered wooden box called an ohitsu.
Brown rice can be sprouted at home if it
has not been irradiated or otherwise altered.
Cultivars grown outside Japan
Arborio rice and
Baldo rice are cultivars of
Japonica grown in Italy Southern India ) closely resembles japonica.
Two major subspecies of rice (Oryza
sativa L.), indica and japonica, are widely recognized. Japonica rice, which
includes temperate and upland (tropical) cultivars, has been less well
characterized by DNA markers than indica rice.
The present study was undertaken to quantify genetic
diversity with random amplified polymorphic DNA (RAPD) markers in a sample of
134 predominately japonica cultivars and two wild species (O. nivara Sharma
et Shastry and O. rufipogon Griffith
Ten oligonucleotide primers produced 30 bands showing
clear polymorphisms. The indica and japonica cultivars were classified into
separate groups by cluster analysis. Clustering was less pronounced within the
japonica group. Tropical japonicas (including U.S.
Japanese rice
(Oryza sativa var. japonica) is a short-grain variety of rice that grows well
in both tropical and cool-weather climates. Prized in Japanese cuisine for its
nutty fragrance and soft texture, its sticky consistency makes it a staple in
dishes such as sushi and mochi. Because rice growing is a time- and
labor-intensive process relative to the amount of yield, rice is typically
grown commercially in large paddies.
Japonica rice is typically grown in
temperate countries like South
Korea
Developing japonica rice for the tropics
IRRI’s japonica
rice breeding program, which is now known as Germplasm Utilization Value Added (GUVA), started
in 1991, in collaboration with the Republic of Korea
So,
during the initial stage of the breeding program, every year, scientists identified
and selected, from the Korean Seed Multiplication Project’s nursery, germplasm
(plant genetic material) that showed good performance in the Philippines
At the early
stage of the breeding program, scientists identify and select genetic material
that serve as base material for breeding populations of japonica rice suited in a tropical environment. During field tests,
these were found to be less sensitive to longer exposure to sunlight and higher
temperature. Plant growth does not vary much under the different environments
of Korea and the Philippines
They were found to be less sensitive to
longer exposure to sunlight and higher temperature, and also did not differ
much in plant growth under the varying environments of Korea and the Philippines
The first of the two cultivars in the Philippines Republic
of Korea
Released in
the Philippines
The product, MS11, is a semidwarf (90 cm),
early-maturing (112 days) variety, and has the typical characteristics of japonica
grain—short rounded shape, low amylose content (15.5%), and low gelatinization
temperature. In the three- season multilocation trials from the wet by Kyung-Ho Kang.
Hence, the
Germplasm Utilization Value Added project paved the way for scientists to breed
elite rice breeding lines that, in turn, provided the base materials for
breeding two varieties of temperate japonica rice suited to the tropical
conditions of the Philippines—NSIC Rc220 or IRRI 152 and NSIC Rc170 or IRRI
142, now called MS11.
Recently, RDA
ceremonially handed over MS11 to farmers for cultivation on the Philippine island of Bohol
The project
resulted in two cultivars, the MS 11, or IRRI 142 and IRRI 152. MS 11, released
in 2008, is a cross between two Korean varieties namely Jimnibeyo, which has
high grain quality, and Cheolweon 46 which is highly resistant to pests and
diseases in the tropics.
The second temperate japonica rice, NSIC Rc220 or IRRI 152, was released in 2009.
Locally known as Japonica 1, this cultivar is also a semidwarf (89 cm),
early-maturing (109 days), and high-yielding
variety. Again, in three-year multilocation trials conducted during the wet seasons
of 2007 to 2008, it demonstrated a 25% greater yield advantage over MS11. And,
strikingly, it was evaluated to have better eating quality—comparable with that
of the highly regarded Koshihikari, a japonica rice widely grown in Japan
Both IRRI 152
and MS11 were approved for large-scale planting by the National Seed Industry
Council of the Republic
of Korea island of Bohol
It is
expected that local cultivation of these high-quality lines will give farmers
higher returns. Consumers as well can enjoy this semiglutinous rice at
affordable prices.
Traditionally grown in cooler regions, japonica varieties, which are developed
by IRRI, can now be cultivated. It is expected that local cultivation of
these high-quality lines will give farmers higher returns. Consumers as well
can enjoy this semiglutinous rice at affordable prices.
On the website “Rice
Today” April-June 2010 seasons of 2001 to 2002,
MS11 yielded an average of 4.5 tons per hectare, with a premium milling and
head rice recovery of 70 and 61%, respectively.
Now, many elite temperate japonica lines adaptable to tropical
climate are being developed at IRRI through the GUVA program. These lines are expected
to provide base materials for intersubspecies hybridization to develop
intermediate varieties. These intermediate varieties will be another breeding
goal for the GUVA program to achieve genetic improvement for yield potential,
canopy architecture, lodging tolerance, and resistance to major pests and environmental
stresses that currently pose a threat to the temperate japonica varieties’
growth in tropical conditions.
With the release of the two japonica rice cultivars,
a growing taste for japonica rice in
the Philippines
While South and Southeast Asians, for example,
prefer long-grain rice such as basmati and jasmine, Northeast Asians prefer
medium-grain rice, known as japonica.
This latter type of rice thrives in temperate areas. Hence, in countries where
it is not traditionally grown, consumers need to pay more to obtain it.
This may soon change, however, as the
International Rice Research Institute (IRRI) has recently developed two temperate
japonica rice varieties released in the Philippines
References
1-http://en.wikipedia.org/wiki/Oryza_sativa
From Wikipedia, the free encyclopedia
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