— 31 IREC Farmers' Newsletter No. 201 — Autumn 2019 Challenges Rice breeders constantly need to combine a wide range of traits into a new variety. The Australian rice industry is targeted towards premium quality and therefore new varieties for southern NSW need to have high yields and specific quality attributes. Breeders have also targeted essential agronomic traits such as seedling vigour, lodging resistance and growth duration. They strive to increase to make improvements for at least one trait (referred to as ‘genetic gain’) with fixed resources. Predicted climate variability will almost certainly affect water availability and a range of abiotic stresses such as cold and heat tolerance, straight-head tolerance and transient drought. These traits are difficult to study and accurately measure, preventing routine screening methods to be developed. Improving water use efficiency and adaption to water-limited conditions at different growth stages will be a top priority. New molecular technologies In the past 30 years, the development of ‘DNA markers’ (also called molecular markers) have provided breeders with new tools for selection and analysis. DNA markers provide breeders with genetic information by ‘fingerprinting’ rice plants to track specific genes or make predictions for traits based on the genetic makeup. The methods used are very similar to the methods used in forensic science labs (as shown in late night TV shows!). Using markers to screen breeding populations — marker-assisted selection (MAS) — is more efficient than using conventional methods leading to improved accuracy, reduced labour or cost savings. The implementation of molecular breeding has been widely adopted in most plant breeding programs around the world. The Yanco rice breeding program has been using molecular markers in rice breeding for many years for traits such as amylose content and fragrance, and was in fact an early adopter of marker technology on par with the most advanced rice programs in the world, to speed up the breeding process. There have been incredible advances in rice molecular research in the last 20 years. Due to its small genome size and use as a model cereal species, rice was the first crop genome to be sequenced in 2005, representing a major scientific breakthrough. In 2014, due to recent technological improvements, more than 3000 rice genomes are now publicly available. This amount of information is not available for other crops. Genomics has enabled considerable information to be discovered about the genetic control of traits by using gene mapping approaches. Once a gene has been mapped, it provides opportunities to use markers for routine screening. It is expected that genomics research will facilitate the characterisation of genes controlling high priority traits. — 31 IREC Farmers’ Newsletter No. 201 — Autumn 2019 Rice breeding in Australia – challenges and opportunities