Arkansas Agricultural Experiment Station researchers were awarded grants from the U.S. Department of Agriculture to improve rice quality. (U of A System Division of Agriculture photo)
Arkansas Agricultural Experiment Station researchers were awarded grants from the U.S. Department of Agriculture to improve rice quality. (U of A System Division of Agriculture photo)

Fast facts

  • USDA-NIFA grants awarded to Arkansas researchers to improve rice quality
  • High nighttime temperature tolerance sought through genetic markers
  • Flavor chemist analyzing variation in flavor profiles across variety of rice cultivars

Fayetteville, AR (July 2, 2024) — Research in Arkansas to improve rice quality was recently supported with two new U.S. Department of Agriculture grants that total over $885,000.

Arkansas is the leading rice producer in the nation with nearly 1.5 million acres planted in the grain that is a staple crop for more than half of the world’s population, according to the USDA Economic Research Service.

The USDA’s National Institute of Food and Agriculture recently announced the following rice research grants through the Agriculture and Food Research Initiative.

Breeding for high nighttime temps

Christian De Guzman, assistant professor of rice breeding and genetics with the Arkansas Agricultural Experiment Station, was awarded a $585,650, four-year grant to seek genetic markers and develop pre-breeding rice lines that tolerate high nighttime temperatures. De Guzman works at the Rice Research and Extension Center in Stuttgart.

The research is being done in collaboration with Samuel Fernandes, assistant professor of agricultural statistics and quantitative genetics, and Vibha Srivastava, professor of plant biotechnology leveraging previous high nighttime temperature studies conducted at the Rice Research and Extension Center. The experiment station is the research arm of the University of Arkansas System Division of Agriculture.

“Rice production is impacted by both daytime and nighttime heat stress,” De Guzman said. “However, high nighttime temperature has a more detrimental effect on rice yield and quality and is considered an immediate threat as the average nighttime temperature is rising rapidly worldwide, including in the U.S.”

Several studies have linked high nighttime temperatures during reproductive stages to low grain yield and quality, De Guzman said. The normal nighttime temperature for the rice growing regions in the U.S. is about 71.6 degrees Fahrenheit. However, the average nighttime temperature has been increasing, especially in the top two rice-growing states of California and Arkansas.

A nighttime temperature of 82.4 F during the flowering stage could lead to significant yield declines and nighttime temps of 89.6 F are “devastating,” he added, and would result in up to 90 percent loss in grain yield. A significant increase in chalkiness has also been observed in rice under high nighttime temperatures. Chalkiness is an undesirable characteristic that not only impacts grain appearance, but also cooking quality and palatability. Those characteristics lead to reduced market value of U.S. rice in the export market.

De Guzman’s goal is to provide plant breeders and rice producers in the U.S. a rice variety that is tolerant to high nighttime temperatures, especially traits that influence grain yield and quality.

Chemical analysis research

Scott Lafontaine, assistant professor of flavor chemistry for the University of Arkansas System Division of Agriculture and the Arkansas Agricultural Experiment Station, was awarded a $300,000, two-year grant to generate a more comprehensive understanding of rice flavor to make U.S. varieties more competitive on the global market.

Rice that is imported from Thailand and India has a big impact on the U.S. rice industry, and U.S. rice imports are projected to represent an all-time high of about 32 percent, or $1.98 billion, of domestic rice use in 2023, Lafontaine stated in his grant proposal.

“Overall, this is because flavor plays a major role in consumer preference, and consumer demand has grown for Asian aromatic varieties such as jasmine from Thailand and basmati from India,” Lafontaine said. “To compete effectively with the imported jasmine rice market, U.S. rice breeders need to develop cultivars with similar but superior and possibly novel flavors.”

Lafontaine will investigate the variation in flavor profiles across a variety of rice cultivars from U.S. breeding programs including the University of Arkansas Division of Agriculture, Louisiana State University, and the California Cooperative Rice Experiment Station. He will also chemically analyze rice samples from the USDA-Agricultural Research Service World Rice Collection and subsets of genetically diverse genome-mapped accessions. After analyzing the chemical compounds of different varieties, he’ll use statistics to select a collection of about 10 to 20 of the most diverse samples for sensory analysis.

“In this way, we will establish a tool so that breeders can better design flavor-forward aromatic rice varieties and set indicators for the key performance of U.S. aromatic rice performance,” Lafontaine said.

The work will facilitate evaluation of the chemical characteristics in crops which are important for driving unique flavor characteristics in a cost-effective manner, Lafontaine added.

To learn more about Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website: https://aaes.uada.edu. Follow on Twitter at @ArkAgResearch. To learn more about the Division of Agriculture, visit https://uada.edu/. Follow us on Twitter at @AgInArk. To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit www.uaex.uada.edu.

Christian De Guzman is an assistant professor of rice breeding and genetics with the Arkansas Agricultural Experiment Station. (U of A System Division of Agriculture photo)
Christian De Guzman is an assistant professor of rice breeding and genetics with the Arkansas Agricultural Experiment Station. (U of A System Division of Agriculture photo)
Scott Lafontaine is an assistant professor of flavor chemistry for the University of Arkansas System Division of Agriculture and the Arkansas Agricultural Experiment Station. (U of A System Division of Agriculture photo)
Scott Lafontaine is an assistant professor of flavor chemistry for the University of Arkansas System Division of Agriculture and the Arkansas Agricultural Experiment Station. (U of A System Division of Agriculture photo)