Breeding the chalk out of rice

Dr Melissa Fitzgerald is looking for ways to overcome the problem of chalky rice, which occurs in high temperatures during grain filling, and threatens the rice supply of the 2.5 billion people who depend on it every day.

Chalkiness weakens rice grains, making them prone to breaking during polishing, and cutting the amount of edible grain available. Chalk in rice cuts its value on domestic markets by around 25%, and even more on the international market.

To date no breeding program has been able to overcome chalkiness in rice, but through an ACIAR-funded research project Dr Fitzgerald has recently made a breakthrough in her investigation of possible molecular markers to enable breeders to select against it.

Recent breakthrough

The ACIAR-funded research project is being conducted at the International Rice Research Institute (IRRI) in the Philippines, where Melissa has worked for the past five years at the Grain Quality, Nutrition and Postharvest Center she helped establish, and also at Yanco, Australia.

Melissa’s team recently identified DNA sites that cause chalkiness in rice, giving them the confidence that they will find the molecular markers to help breeders select against chalk, and overcome this problem which affects rice crops in both Australia and overseas.

Melissa estimates that reducing chalk in rice would help increase food security and farmer incomes by boosting the yield of edible rice per hectare, possibly by as much as 7%.

“Chalk is a real problem of climate change and has the potential to wipe out yield. Imagine if you had a nice looking crop, with nice looking panicles and you went with high expectation to the local mill and then it all crumbled to pieces,” she said.

For more information on IRRI: http://irri.org