Identification of resistance to Sugarcane streak mosaic virus (SCSMV) and Sorghum mosaic virus (SrMV) in new elite sugarcane varieties/clones in China

Sugarcane mosaic disease is one of the most serious and prevalent viral diseases of sugarcane in China. The use of resistant varieties is the most economical and effective measures for controlling this disease. Sugarcane streak mosaic virus (SCSMV) and Sorghum mosaic virus (SrMV) are the two predominant pathogens of mosaic disease in the cane-growing regions of China. In 2015, 2016, double resistance to SCSMV and SrMV was identified once a year using a combination of artificial stalk-cutting inoculation and RT-PCR detection in 71 new elite sugarcane varieties/clones. Of the 71 new elite sugarcane varieties/clones, 24 were highly (Grade 1) to moderately resistant (Grade 3), and 47 were susceptible (Grade 4) to highly susceptible (Grade 5) to SCSMV. Furthermore, 27 were highly (Grade 1) to moderately resistant (Grade 3), and 44 were susceptible (Grade 4) to highly susceptible (Grade 5) to SrMV. Fifteen new elite sugarcane varieties/clones were highly resistant (Grade 1) to resistant (Grade 2) to SCSMV and SrMV. While, five new elite sugarcane varieties/clones (Yuegan 34, Yuetang 55, Yunzhe 03-258, Yunzhe 05-51, Yunzhe 06-80) were highly resistant (Grade 1) to SCSMV and SrMV. We defined the resistance of 71 new elite sugarcane varieties/clones to the two main pathogens of mosaic disease and identified 15 resistant to both SCSMV and SrMV. These results provide an elite resistance resource for effective prevention and control of mosaic disease and may serve as a reference for commercial varieties.