Featured Research

from universities, journals, and other organizations

NC State Geneticists Study Origin, Evolution Of "Sticky" Rice

Date:
October 24, 2002
Source:
North Carolina State University
Summary:
A study by two North Carolina State University geneticists traces the origin and evolution of a genetic mutation that long ago led to the creation of a type of rice known as glutinous, or "sticky," rice.

A study by two North Carolina State University geneticists traces the origin and evolution of a genetic mutation that long ago led to the creation of a type of rice known as glutinous, or "sticky," rice.

Related Articles


The molecular genetic research leads researchers to believe that glutinous rice - which differs from non-glutinous, or common, rice on account of a mutation in its Waxy gene that suppresses the formation of a starch called amylose - most likely originated a single time in Southeast Asia. Further, DNA evidence - namely the lower-than-expected genetic variability in the Waxy gene - suggests that early domesticators of glutinous rice liked its adhesive quality and wanted to preserve that particular trait.

Dr. Michael Purugganan, associate professor of genetics, and Dr. Kenneth Olsen, post-doctoral research associate in genetics, publish their findings in the Oct. 23 edition of Genetics.

To learn more about the origin and evolution of sticky rice, the researchers studied 105 glutinous and non-glutinous samples of rice donated from the multitudinous stock kept by the International Rice Research Institute in Los Banos, Philippines.

Rice contains two starches: amylose and amylopectin. Glutinous rice lacks amylose; in fact, it is the lack of amylose that gives it its sticky composition. Non-glutinous rice - what you'd find if you cooked up a name-brand package of rice from the grocery store, for example - contains up to 30 percent amylose; the result is rice with grains that separate.

Glutinous rice is the staple food in some areas in Southeast Asia, including parts of Laos, Thailand and Cambodia, the researchers say. Sticky rice has also migrated north to become an important part of the diet in places like China and Japan. Used primarily in a number of desserts - rice cakes, for example - sticky rice has achieved important cultural standing in East and Southeast Asia.

But Asian folklore diverges on the origin of glutinous rice, Purugganan says. He found both a Laotian Buddhist legend charting the existence of glutinous rice to about 1,100 years ago and Chinese folklore that indicated the existence of glutinous rice more than 2,000 years ago.

"Since no one really knows where glutinous rice came from, we wanted to find its origin using molecular means," Purugganan says. "We also wanted to find out the number of times the mutation in the Waxy gene that suppresses amylose, which produces glutinous rice, arose during rice domestication. And, we wanted to see if the Waxy gene showed evidence of selection by early Asian farmers."

Performing genetic sequencing of these samples at NC State's Genome Research Laboratory, Purugganan and Olsen assembled a "gene tree," or network that represents patterns of genetic differences among the DNA sequences, Olsen explains.

Using the gene tree, the researchers found that sticky rice's genetic mutation maps to a single mutation on the gene tree, suggesting that the mutation occurred a single time rather than more than once, Olsen says. Looking at the geographic locations of the rice DNA sequences that are direct ancestors of the mutation, the researchers found fairly strong evidence that Southeast Asia was the geographic origin of sticky rice. This squares with the fact that sticky rice is a staple in some parts of Southeast Asia.

"This type of research really opens up the window of not only how crops originate, but also how specific features evolve," Purugganan says. Olsen adds, "This is one of the first times that anyone has looked within a crop species at the evolutionary and geographical origins of important domestication traits in crops."

Purugganan and Olsen now plan to study other genes involved in starch synthesis in rice.

Research funding for the study of the origin and evolution of glutinous rice was provided by the Alfred P. Sloan Foundation.


Story Source:

The above story is based on materials provided by North Carolina State University. Note: Materials may be edited for content and length.


Cite This Page:

North Carolina State University. "NC State Geneticists Study Origin, Evolution Of "Sticky" Rice." ScienceDaily. ScienceDaily, 24 October 2002. <www.sciencedaily.com/releases/2002/10/021023064638.htm>.
North Carolina State University. (2002, October 24). NC State Geneticists Study Origin, Evolution Of "Sticky" Rice. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2002/10/021023064638.htm
North Carolina State University. "NC State Geneticists Study Origin, Evolution Of "Sticky" Rice." ScienceDaily. www.sciencedaily.com/releases/2002/10/021023064638.htm (accessed October 25, 2014).

Share This



More Plants & Animals News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Black Bear Cub Goes Sunday Shopping

Black Bear Cub Goes Sunday Shopping

Reuters - Light News Video Online (Oct. 23, 2014) Price check on honey? Bear cub startles Oregon drugstore shoppers. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Dances With Wolves in China's Wild West

Dances With Wolves in China's Wild West

AFP (Oct. 23, 2014) One man is on a mission to boost the population of wolves in China's violence-wracked far west. The animal - symbol of the Uighur minority there - is under threat with a massive human resettlement program in the region. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
Breakfast Debate: To Eat Or Not To Eat?

Breakfast Debate: To Eat Or Not To Eat?

Newsy (Oct. 23, 2014) Conflicting studies published in the same week re-ignited the debate over whether we should be eating breakfast. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins