Higher rice yields with no extra water

Annual rice production losses due to cold are 5 to 10 per cent, or $44 million, and when cold snaps occur about every 4 years losses soar to up to 40 per cent.

Water is used to buffer cold-sensitive rice against cold - a cold tolerant rice variety could reduce this water use.

CSIRO Plant Industry research in Canberra has shown cold snaps prevent sugar in rice being transported to the pollen. Pollen development is then aborted and without pollen no grain is produced.

There is a 1-2 day opportunity for sugar to be transported from a layer surrounding the pollen to the pollen itself.

If a cold snap occurs then, there is no further chance for sugar to get to the pollen to allow it to grow.

Dr Rudy Dolferus has found a gene that produces a hormone that can prevent the development of one of the enzymes that moves sugar to pollen.

In conventional rice more of this hormone is produced when it is cold, but in cold tolerant rice the hormone's levels remain the same - allowing the enzyme to develop.

Why this gene behaves differently is now being investigated.

If there is a difference in the gene then DNA markers that flag its location can be identified - speeding up the delivery of a cold tolerant rice variety.

This research was supported by the Rice Cooperative Research Centre.

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