Chalk9 gene found in rice to cut grain chalkiness and breakage
Why in the news
A team at the Agricultural College of Yangzhou University, China, found a gene behind chalky, easily broken rice grains.
Key facts
- Rice feeds over half of the world’s population, and chalkiness raises breakage during milling.
- Genomes of 175 varieties were sequenced; a segment on chromosome 9 regulates the Chalk9 gene in the endosperm.
- Chalk9-H (high chalkiness) was common before 1990; Chalk9-L (low chalkiness) rose after 1990 through breeding programmes.
About chalkiness
- Grains look opaque rather than translucent over large areas.
- Assessed by chalky grain rate and degree of chalkiness.
- Influenced by genetics and high temperature.
- Chalky grains are weaker, so fewer whole, saleable grains are recovered, lowering quality and market value.
Significance
- Grain quality: breeding with this gene can lower chalkiness and lift whole-grain yield.
- Economics: more unbroken rice means better profits for farmers and millers.
- Consumer value: whole grains are prized, improving marketability and food quality.
Exam angle
- Gene: Chalk9, on chromosome 9.
- Varieties compared: Chalk9-H versus Chalk9-L.
- Institution: Yangzhou University, China.