SmutBuster: accelerated breeding of smut-resistant sugarcane varieties : SRDC final report BSS325

Abstract

Sugarcane smut is caused by the fungus, Ustilago scitaminea Syd., and is one of the most serious diseases of sugarcane. At the end of 1983, only the sugar industries of Australia and Fiji remained free from smut. Sugarcane smut was reported for the first time in Australia in July 1998 in the Ord River Irrigation Area. Eight years later, smut was identified on the east coast of Australia at Childers. By December 2007 sugarcane smut was widespread and established in the Bundaberg?Isis, Central Queensland and Herbert River districts, and by 2010 the Mulgrave, Tully and Burdekin districts were also infested. The average yield loss reported in papers at the time of the east coast smut incursion was 6% yield loss for each 10% increase in per cent-infected plants. To minimise losses susceptible varieties will need to be completely replaced with equivalent/higher yielding smut-resistant varieties, as fast as possible. This would necessitate changing ~80% of the2006 sugarcane crop. Replacement of susceptible varieties will be achieved, not only by rapid scale-up of smut-resistant varieties, but also accelerated development of high yielding,smut-resistant varieties. The parental pool of high breeding value, smut-resistant germplasm was however severely limited, adversely impacting the core crossing program. Without a significant plant breeding response, the rate of genetic gain for productivity would decrease and fewer productive, smut-resistant varieties would be released from the BSES-CSIRO Sugarcane Variety Improvement Program. The SmutBuster project was a key component of the RD&E response to sugarcane smut with the specific objective of developing high yielding smut-resistant varieties through the utilisation of high breeding value parental germplasm with susceptible reaction to smut.