Developing Japanese rice for the tropical areas

Developing japonica rice for the tropical areas

RDA Administrator Dr. Jae-Soo Kim (Korea) and IRRI Director General Dr. Robert Zeigler
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 some time between 3500 and 1200 BC. The cultivation of rice in Korea and Japan during that time occurred on a small-scale, fields were impermanent plots, and evidence shows that in some cases domesticated and wild grains were planted together. The technological, subsistence, and social impact of rice and grain cultivation is not evident in archaeological data until after 1500 BC. For example, intensive wet-paddy rice agriculture was introduced into Korea shortly before or during the Middle Mumun Pottery Period (c. 850–550 BC) and reached Japan by the final Jōmon or initial Yayoi periods c. 300 BC.

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 sell ready-polished rice in 10 kg, 5 kg, and smaller bags. Brown rice is usually sold in 30 kg bags. Japonica should not be confused with Jasponica rice – a cross between the long-grained and fragrant Thai Jasmine rice and the sticky, soft Japanese rice.
Rice is cultivated throughout Japan. In Hokkaidō, Japan's northernmost island, hardier varieties are grown. In Honshū, the Japanese mainland, varieties such as koshihikari are grown.
Rice is eaten in several ways in Japan, as plain rice "gohan" (lit. "cooked rice" or "meal of any sort") or often with a topping of furikake , nattō or nori , as well as for sushi . Leftover rice is often reused as ochazuke (rice with green tea) or chāhan (fried rice).
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; most modern rice cookers can be set ahead by a timer, so that rice will be ready for the morning meal. The rice cooker can also keep rice moist and warm. Rice kept warm like this remains edible for several hours, so that rice need be made only once per day.
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 and other Mediterranean countries. Idly rice- the short grained and stout variety grown in Tamil Nadu (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. long-grain types) usually clustered together but no firm boundary was found between the tropical and temperate types.
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. Because it is a high-quality and a high-yielding variety, japonica rice fetches a higher cost than the tropically grown indica rice. Farmers who can grow japonica rice locally stand to earn greater return on their incomes. Consumers, on the other hand, can afford to enjoy this semi-glutinous rice at affordable prices, rather than paying more for the imported japonica

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, to develop high-quality, high-yielding temperate japonica rice cultivars that can adapt and grow in the tropical zone. Under warm conditions, most temperate japonica rice varieties show stunted growth and develop weak tillers, small panicles, and premature heading because these varieties are sensitive to short daylength and high temperature.
 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. These selections served as base materials to develop breeding populations of temperate japonica rice that can adapt to tropical conditions.
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, NSIC Rc170 or IRRI 142, now called MS11, was released in 2008. MS11 is a cross between two varieties from the Republic of Korea, namely, Jinmibyeo and Cheolweon 46. Jinmibyeo has high grain quality, while Cheolweon 46 has high resistance to pests and diseases in tropical conditions.
Released in the Philippines in 2008, MS11 is a cross between two Korean varieties, namely, Jinmibeyo, which has high grain quality, and Cheolweon 46, which is highly resistant to pests and diseases in the tropics.
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, at an event marking RDA and IRRI's long and productive collaboration.
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. RDA officially turned over MS 11 rice to farmers for cultivation in the Philippine island of Bohol in early 2010.
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 TodayApril-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, especially among urban dwellers and the younger generation, will soon be satiated at more reasonable costs. Korean, Japanese, and Taiwanese restaurants and hotels would no longer need to look back to their origins to cater to their customers’ preference. Most importantly, local farmers who grow this type of rice could soon take advantage of the expanding market, reap higher profits, and, we hope, lead better lives.
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. The Rice Technical Working Group of the National Seed Industry Council through the National Cooperative Tests Network, led by the Philippine Rice Research Institute, has approved two temperate japonica rice cultivars, NSIC Rc170 or IRRI 142 and NSIC Rc220 or IRRI 152, for large- scale planting. This development is expected to provide local farmers with higher returns, and subsequently, allow consumers to enjoy this quality rice at a more affordable price.
1- From Wikipedia, the free encyclopedia

No comments:

Post a Comment