Rice Breeding: Nighttime Stress Tolerance
- As nighttime temperatures climb in key rice-producing areas, scientists are intensifying efforts to develop heat-tolerant rice varieties.
- Arkansas, which produces half of the rice grown in the united States, has roughly 1.4 million acres dedicated to the crop, a staple food for billions worldwide, according...
- Vibha Srivastava, professor of plant biotechnology at the University of Arkansas System Division of Agriculture, said incorporating heat tolerance genes into Arkansas rice is challenging but showing progress.She...
Combat the impacts of rising nighttime temperatures on crucial crops.This article outlines critical research into rice breeding, focusing on developing heat tolerance in rice varieties. Scientists leverage traditional breeding and gene editing to safeguard yields and grain quality, with U.S. rice production, especially in Arkansas, facing meaningful challenges. Learn how researchers, backed by USDA grants, investigate pathways to adapt to rising temperatures, including techniques like gene editing.The goal is to produce high-quality rice, even under harsh conditions, and cloning key genes like Chalk5 may unlock new strategies for improvement; a key focus within the Arkansas program. News Directory 3 provides updates on this developing story. Discover what’s next for the future of rice.
Rice Breeding Focuses on Nighttime heat Tolerance as temps Rise
As nighttime temperatures climb in key rice-producing areas, scientists are intensifying efforts to develop heat-tolerant rice varieties. Researchers are exploring both conventional breeding methods and cutting-edge gene editing techniques to combat the threat to yields and grain quality.
Arkansas, which produces half of the rice grown in the united States, has roughly 1.4 million acres dedicated to the crop, a staple food for billions worldwide, according to the USDA Economic Research Service.
Vibha Srivastava, professor of plant biotechnology at the University of Arkansas System Division of Agriculture, said incorporating heat tolerance genes into Arkansas rice is challenging but showing progress.She suggests gene editing, which avoids introducing foreign DNA, as another avenue.
Srivastava and her colleagues, Christian De Guzman and Samual B. Fernandes, recently published a review article in Current Opinion in Plant Biology, summarizing current research on breeding rice for high nighttime temperature tolerance.
The USDA has awarded De Guzman,Fernandes,and Srivastava a four-year,$585,650 grant to support their work in breeding rice for high nighttime tolerance.
Rice is particularly vulnerable to high nighttime temperatures during its flowering and grain-filling stages. Most varieties are sensitive to temperatures above 82.4 degrees Fahrenheit (28 Celsius). These elevated temperatures can led to significant yield losses and a decline in grain quality, often expressed as undesirable “chalkiness.” Studies suggest that high nighttime stress can slash grain yields by up to 90% and substantially increase chalkiness.
Srivastava noted that while the precise genetic mechanisms behind nighttime heat stress susceptibility remain unclear, increased respiration rates divert energy from growth and biomass formation.
While no U.S. cultivars currently possess sufficient nighttime heat tolerance, an Indian variety, nagina 22, exhibits this trait. However, when grown in Arkansas, it displays undesirable characteristics such as small grain size and chalkiness.although Nagina 22 has been crossed with modern cultivars, its heat tolerance genes have not yet been cloned, hindering the request of gene editing. Srivastava suggests gene editing could improve Nagina 22’s traits or enhance crosses involving the variety.
Advanced breeding lines within the Arkansas Rice Breeding Programme may also be candidates for gene editing, provided they demonstrate improved yield and reduced grain chalkiness under nighttime heat stress. A key focus will be reducing the naturally high grain chalkiness of Nagina 22 and its derivatives. Cloning and analyzing Chalk5,a major DNA region associated with chalkiness,could pave the way for reducing chalkiness through gene editing,Srivastava said.
“Our goal is to get more production and more flavorful taste when it comes to rice, but quality of the grain is significant,” Srivastava said.
What’s next
With national studies indicating a trend toward warmer nights,the development of heat-tolerant rice varieties is becoming increasingly critical to ensure stable yields and maintain grain quality for consumers.