— 36 IREC Farmers' Newsletter No. 200 — Spring 2018 Hybrid rice is well known to have a significant yield advantage over inbreeding rice varieties. However hybrid rice has historically had a bad reputation for high seed cost and poor grain quality. FOR these and other reasons hybrid rice varieties have not previously been pursued by the Australian rice breeding program. However, recent technological advances in hybrid breeding have largely overcome these problems and hybrid rice varieties are gaining popularity around the world. Hybrid rice was developed in China in the 1970s, and is now well established in several major temperate and tropical rice growing areas around the world. Commercial results of hybrid varieties in China and USA over the last 10 years report yield advantages of around 10–20% over equivalent conventional varieties. Hybrid rice varieties have been rapidly adopted in the southern USA rice growing region with, on average, more than a third of the rice area planted to hybrids. Southern USA hybrid varieties have proved popular with rice growers because of their yield advantage over inbred varieties, competitive growth habit and shorter growth duration. Research has shown there is no difference in the grain quality of southern US hybrid varieties compared to inbred varieties. Investigating Australian germplasm for hybrid potential Genomic analysis of the Yanco rice germplasm collection has shown that the Australian rice breeding program has two separate pools of elite germplasm, which could be the basis for a hybrid breeding program. We investigated an F1 hybrid with the well-known commercial varieties Reiziq and Doongara as parents to see if combining the two pools of elite Australian rice germplasm would generate hybrid vigour, and provide an indication of the potential for developing hybrid rice varieties adapted for Australia. We conducted an experiment in the rice breeding program glasshouse at Yanco, producing an F1 hybrid by controlled cross-pollination between Reiziq as the female parent and Doongara as the male parent. The trial was planted in 2017, and single plants were grown in 200 mm pots. We compared 10 replicates of the F1 hybrid and the hybrid parents at three times of sowing. An experiment at Yanco is investigating hybrid vigour in Australian rice. From left to right are example plants of Reiziq, the F1 hybrid and Doongara, during grain filling in glasshouse trials. — 36 IREC Farmers' Newsletter No. 200 — Spring 2018 Prospects for hybrid rice