Screening Australian sugarcane clones for smut reaction in Indonesia: initial results

The presence of sugarcane smut in Western Australia poses a potentially serious risk to the eastern Australian sugar industries. An existing agreement with the Indonesian Sugar Research Institute (ISRI) for pre-emptive screening of Australian germplasm was renegotiated after the incursion in WA. Two small-plot, replicated smut resistance trials, containing 296 clones, were planted in Indonesia and were rated monthly in three trial/crop combinations. Combined analyses of variance of percent smut-infected stools for the monthly inspections revealed highly significant differences among clones and among inspections and highly significant clones x inspections interaction. Genetic coefficients of variation and broad sense heritabilities were high. Significant gains from selection are achievable. The crops x clones interaction term was not significant in a combined analysis of variance of the final inspections of the plant and ratoon crops of Trial 1. This suggests that trials could be assessed in the ratoon crop only. Assessment on a stool or stalk basis was identical genetically, but practicality favours stool assessment. A broad range of smut reaction exists in the Queensland cultivars tested. Initial results suggest 70% of all clones tested are susceptible to smut. However, 51% of the crop is currently produced by resistant cultivars. The most widely grown resistant cultivars are Q96, Q124, Q151, and Q155. Breeding highly productive smut-resistant cultivars is essential, will be readily achievable, and will commence immediately. This depends upon maintaining strong collaborative links with the ISRL.