Go to top of page

Primary tabs

Breeding for low chalk in rice

This project aims to validate functional molecular markers that can routinely be used to reduce chalk in rice breeding programs.
Chalk reduces the market price of rice considerably. Chalky areas appear as opaque streaks in translucent rice grains due to the aborted formation of starch granules and protein impairment. Chalkiness can vary from very low (less than 2%) to very high (up to more than 20%).
A previous project, CIM-2006-176, mapped the genetic variation for the low-chalk trait, despite a widely held belief that environmental variation caused the trait. A second project, SRA CIM-2014-024, fine-mapped the genetic region to chromosome 5, which was linked to low chalk through genome-wide association studies.
The project will transfer the low-chalk trait into a high-chalk background using markers (haplotypes) identified in CIM-2014-024 and functionally validate the three candidate genes identified in CIM-2014-024.
This would reinforce the value of IRRI's intellectual property, provide proof of concept to breeders, attract interest and funding from private rice breeders, and increase confidence that grain chalk can be addressed through genetics.