Sugarcane mild mosaic virus in commercial varieties and advanced lines in Florida

Authors: Soares, Juliana; Adhikari, Bishwo; HU, XIAOJUN - Animal And Plant Health Inspection Services (APHIS), National Wildlife Center; Sood, Sushma

Submitted to: International Society of Sugar Cane Technologists Proceedings
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/12/2025
Publication Date: 3/13/2025
Citation: Soares, J.M., Adhikari, B.N., Hu, X., Sood, S.G. 2025. Sugarcane mild mosaic virus in commercial varieties and advanced lines in Florida. International Society of Sugar Cane Technologists Proceedings. 32, 297-302, 2025.

Interpretive Summary: Several viral diseases affect sugarcane production worldwide. One of them is Sugarcane mild mosaic virus (SCMMV) found recently in a commercial cultivar in the USA for the first time. Therefore, this study aimed to survey commercial cultivars and advanced lines for SCMMV infection. Leaf samples from seven principal commercial varieties, those grown on over one percent of sugarcane acreage, were collected from the USDA-ARS Sugarcane Field Station and farms throughout the sugarcane growing area in Florida. In addition, samples were taken from non-principal commercial varieties and advanced lines. SCMMV infection was tested using reverse transcriptase PCR with SCMMV-specific primers. The results showed that all the samples from the principal commercial varieties from the Sugarcane Field Station tested positive for SCMMV. The growers' farms had fewer principal and non-principal commercial varieties infected with SCMMV mostly due to the use of clean seed cane obtained through meristem tissue culture for planting. This method has been shown to effectively remove SCMMV. Hence, using clean seed canes is essential to minimize the impact of SCMMV.

Technical Abstract: Several viral diseases affect sugarcane production worldwide. In 2022, a severely stunted principal commercial variety, CP 06-2400, growing in the crossing line at the USDA-ARS Sugarcane Field Station in Canal Point, Florida, was tested using high-throughput sequencing and found to be infected with Sugarcane mild mosaic virus (SCMMV). This virus had not been previously reported in commercial cultivars in the USA. Therefore, this study aimed to survey commercial cultivars and advanced lines for SCMMV infection. Leaf samples from seven principal commercial varieties, those grown on over 1% of the sugarcane area, were collected from Canal Point and farms throughout the sugarcane growing area in Florida. In addition, samples were taken from 11 non-principal commercial varieties and 13 advanced lines. SCMMV infection was tested using reverse transcriptase PCR with SCMMV-specific primers. All the samples from the principal commercial varieties from Canal Point and only three samples from growers’ farms tested positive for SCMMV. Only one non-principal commercial variety from one farm tested positive. However, samples from several advanced lines collected from all the farms tested positive. The growers' farms had fewer principal and non-principal commercial varieties infected with SCMMV mostly due to the use of clean seed canes obtained through meristem tissue culture for planting. This method has been shown to effectively remove SCMMV, which is further supported by the finding that the SCMMV-positive advanced lines on these farms that were not grown from clean seed canes. Like other members of the genus Ampelovirus, SCMMV is transmitted by pink sugarcane mealybugs (Saccharicoccus sacchari). An increased infestation of sugarcane in recent years may explain the higher incidence of SCMMV infection at Canal Point. Hence, using clean seed canes is essential to minimize the impact of SCMMV.