— 38 IREC Farmers' Newsletter No. 200 — Spring 2018 two separate pools of germplasm in the Australian rice breeding program and demonstrated that an F1 hybrid can outperform elite parents from both these pools. Hybrids between the two subspecies could be explored to see if they give better performance. We are not aware of any other research documenting the performance of hybrids developed from Australian rice germplasm. We used two commonly grown varieties (Reiziq and Doongara) as an initial test for hybrid vigour. It is possible that other hybrid parents exist in the Australian breeding program that could give even better combinations of hybrid performance, especially where the two germplasm pools of elite breeding material in the breeding program could be combined. Our experiment measured single plants grown under controlled conditions, so our results are likely to be different to results obtained from larger experiments conducted under field crop conditions. Our results raise further questions: Will the results we observed translate to the field environment? Is there any trade-off between hybrid vigour and increased yield and other characteristics important in Australian rice, like grain quality or reproductive cold tolerance? And how can hybrid seed be produced in a cost-effective way? Hybrid rice technology and techniques have advanced considerably over recent years. Many of these questions have been addressed in other production systems over a long period of time, to the point where hybrid varieties are an established part of the production system in in several temperate rice growing regions internationally. In order to implement a hybrid breeding program in Australia, effective cytoplasmic male sterility could be integrated into Australian germplasm, or alternatively chemical gametocides could be employed. Other new methods of producing hybrid rice seed should also be explored to identify the best options available. Hybrid technology could be a way of extracting a large genetic gain from elite Australian germplasm in a short time to rapidly realise the yield and water productivity benefits of hybrid rice. New breeding methods are being developed that could overcome many of the challenges previously faced in hybrid rice breeding, and our results indicate that there is a starting point of good hybrid vigour in elite Australian germplasm. Further information Ben Ovenden Rice Breeder Yanco Agricultural Institute E: [email protected] New methods that could overcome many of the challenges previously faced in hybrid rice breeding have potential to rapidly realise the yield and water productivity benefits of hybrid rice. — 38 IREC Farmers' Newsletter No. 200 — Spring 2018 Prospects for hybrid rice BACK TO CONTENTS PAGE