Context:
Rice, the staple food for over half of the world’s population, often faces the problem of chalkiness in grains, which leads to higher breakage during milling. Recently, researchers from the Agricultural College of Yangzhou University, China, identified a key gene, Chalk9, that controls rice chalkiness.
What’s the Discovery?
Scientists have identified a gene that helps rice grains resist breakage during milling, particularly addressing grains with the trait known as chalkiness, a characteristic that makes them brittle and more prone to cracking when polished
- Breakthrough Discovery:
- Researchers sequenced genomes of 175 rice varieties.
- Found a DNA segment on chromosome 9 strongly linked with chalkiness.
- This segment regulates the Chalk9 gene in the rice endosperm.
- Varieties and Breeding:
- Chalk9-H (high chalkiness) was dominant before 1990.
- Chalk9-L (low chalkiness) increased significantly after 1990 due to breeding programs.
- Now, breeders can directly introduce Chalk9-L to improve grain quality.
What is Chalkiness?
- Rice grains are chalky if large parts of them appear opaque instead of translucent.
- Measured by chalky grain rate and degree of chalkiness.
- Leads to higher breakage during milling.
- Influenced by genetic factors and high temperature.
Why Chalkiness Important?
- Chalky grains are weaker and more likely to break during milling.
- This reduces the recovery of whole, commercially acceptable rice, thereby lowering its quality and market value
Why This Matters?
- Improved Grain Quality: By targeting this gene in breeding programs, scientists can develop rice varieties with lower chalkiness, boosting the yield of whole (unbroken) grains.
- Economic Benefit: Higher rate of unbroken rice translates to better profits for farmers and millers.
- Enhanced Food Value: Whole grains are more prized by consumers, improving both marketability and food quality.
