BREEDING SMUT-RESISTANT SUGARCANE VARIETIES IN AUSTRALIA: PROGRESS AND FUTURE DIRECTIONS

SUGARCANE SMUT was found for the first time in Queensland in June 2006. This serious disease can cause total crop loss in susceptible varieties and, at the time of the incursion, 69% of the Queensland crop was produced by susceptible varieties. BSES commenced screening Australian varieties for resistance to sugarcane smut in Indonesia in 1998, a few months after the disease was found in the Ord River Irrigation Area (ORIA) of Western Australia. A total of 1705 clones have been screened for smut resistance in Indonesia and 481 clones have been screened in the ORIA. The screening trials have shown that 69% of the Australian clones were susceptible to smut. These smut resistance ratings have been used to select resistant varieties for release to growers, select parent clones for smut specific crosses and to advise growers of the risk they faced from a smut incursion. When smut was found in Queensland, the ratings obtained from this program played a major role in the emergency response. A smut screening program was commenced in Bundaberg in 2006, once it was clear that smut could not be eradicated. In 2006, 1007 clones were screened for resistance to smut using a method where spores were painted onto the buds. More than 1600 clones have been planted in screening trials in Bundaberg in 2007. The proportion of smut-resistant crosses made in the BSES-CSIRO Variety Improvement Program increased from 0.4% in 2000 to 52% in 2007. Many productive parent clones are highly susceptible to smut, and a program has commenced to recover the genes for high productivity found in these parents by identifying smut-resistant progeny from crosses between susceptible parents and from crosses between susceptible and resistant parents. This will involve developing methods to inoculate true seedlings to rapidly screen the clones for resistance. The paper describes the changes that are being made to the BSESCSIRO Variety Improvement Program to achieve a rapid recovery from the smut incursion.