Mechanized rice production in the United States had its origin on the southwest Louisiana coastal prairies in the latter part of the 19^th century. Production of this important grain crop was well-adapted to this region, and rice cultivation spread rapidly throughout this corner of the state. From Louisiana, production soon moved into Texas, Arkansas and California, then more recently into Mississippi and Missouri. These six states are the backbone of the current U.S. rice industry.

Since the beginning of this industry, there has been a need for the continual development of new technology to boost the productivity and economic viability of rice production. The LSU AgCenter Rice Research Station near Crowley was established to help develop new technology. The station was created through joint efforts among local leaders in the rice industry, the Louisiana Agricultural Experiment Station and the U.S. Department of Agriculture. The station’s initial focus was to provide new varieties to the industry, and this focus has continued. The initial progress in this area came about by bringing in varieties from throughout the world and testing them under southwest Louisiana conditions. A number of improved varieties were provided to the local industry from this screening of international germplasm.

Variety development shifted to the creation of new germplasm or genetic combinations. This involves taking different lines or strains of rice and cross-pollinating them to create new combinations of genes that have never existed before. We then select the offspring from these crosses that appear to have the best combinations of characteristics for production in this region. It takes several generations after a cross is made to eliminate the segregation or non-uniformity that is a result of the cross pollination.

The superior lines from this process are entered in trials that evaluate yield and quality potential as well as numerous other characteristics that influence the potential of a line to become an improved variety. Those lines that continue to display superiority for several years of testing are purified, increased and then released to the industry as a new rice variety.

This process used to take 12-14 years from the initial cross until a new variety was released to seed growers. Breeders have been able to shorten that time span considerably in recent years through various means. One of these is the winter nursery facility in Puerto Rico. This location allows breeders to grow rice year-round and thus produce up to three generations of breeding lines in one year, which can dramatically reduce the delivery time for a new variety. The use of the winter nursery has reduced the average time from a cross to foundation seed to about eight years.

Another tool added to our breeding program is anther culture technology. Simply put, this is a fairly complex system where uniform breeding lines are created in one generation by creating plants directly from the anthers, which are the pollen-bearing parts of the flower. The eventual genetic makeup of the new plant is created by doubling the pollen parent’s DNA, which leads to a uniform (non-segregating) line that can be directly entered into yield testing without having to grow out the line to eliminate the segregation as discussed above.

Marker-Assisted-Breeding (MAS) is another fairly new tool that holds great promise for future variety development. This technology allows one to sample plant tissue at an early stage and detect whether a gene of interest is contained in the genetic makeup of a breeding line. An example here would be in breeding for resistance to sheath blight disease, which is a major cause of yield and quality loss in southwest Louisiana rice production. Before use of MAS, a breeder, working with a pathologist, would have to grow out lines, inoculate with the sheath blight organism, hope for environmental conditions conducive to development of the disease, then evaluate for relative resistance or susceptibility. With MAS, one can collect leaf tissue at the seedling stage, evaluate this in the lab and have a high level of confidence as to whether the resistance gene is in the line.

Yet another tool that has played a major role in variety development is the creation of induced mutations. This is a system where rice seeds are subjected to either chemicals or radiation in an effort to create mutations or changes in the genetic material of the plant. These seed are then grown, and the resulting plants are evaluated to see if any new characteristics may be advantageous. This is the system that was used to create the herbicide-resistant lines now known as Clearfield technology that have become so vital to Louisiana rice production in recent years.

Researchers are continually looking for new methods to expedite the delivery of new superior rice varieties to the Louisiana rice industry. New technological advances are essential for the future of the rice industry.