New Rice
Stock Adds Good Trait to Genetic Collection
By Jim Core
May 28, 2004 New genetic rice stocks from the
Agricultural Research Service add to the
diversity available for rice breeders everywhere.
The latest rice genetic stock, called Guichao 2 eui, is significant
because it marks the first time a gene for a key trait, called elongated
uppermost internode (eui), has been found in an indica rice, the principle rice
type grown in the world. The "eui" trait is beneficial for better
pollen transfer in hybrid rice seed production because the male line
panicles--the plant's flowering heads--are taller than female line panicles. It
can also be used to raise the female panicles and make them more available for
pollination.
This trait is the 11th addition to a new rice collection repository, called
Genetic Stocks-Oryza (GSOR), that was established at the
ARS Dale Bumpers National Rice
Research Center in Stuttgart, Ark., in August 2003. Genetic stock
collections help preserve germplasm, such as plant seed, and these stocks have
characteristics that breeders can use to create new lines with valuable traits.
J. Neil Rutger, director of the Stuttgart center, made the discovery in an
indica cultivar grown there. The recessive gene that caries the eui trait was
previously found only in japonica rice lines. Rutger made the original
discovery of the mutant gene during the early 1980s in temperate japonica
germplasm, the cultivars that produce short, sticky grains. But this trait has
had its greatest use in indicas, so international breeders have spent a lot of
time breeding the japonica source into indicas. The finding means this
time-consuming practice is no longer necessary.
GSOR stocks currently include rice seed stocks produced in Stuttgart. Soon,
more rice lines will be added. ARS, the chief scientific research agency of the
U.S. Department of Agriculture, has recently
committed to long-term storage and distribution of rice seed stock resources
generated from National Science Foundation
and USDA Plant Genome grants.
Seeds are available on request through the
ARS Germplasm Resources Information
Network or through the
GSOR repository
homepage.
|