Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/4/2012
Publication Date: 10/1/2012
Publication URL: http://handle.nal.usda.gov/10113/63042
Citation: Que, Y., Xu, L., Chen, R., Grisham, M.P. 2012. Molecular variation of Sporisorium scitamineum in mainland China revealed by RAPD and SRAP markers. Plant Disease. 96:1519-1525. Interpretive Summary: Sugarcane smut caused by the fungus Sporisorium scitamineum is found worldwide in sugarcane producing countries and can cause serious loss in stalk yield and sugar quality. A study was conducted to determine if the smut fungus is genetically different among the six primary sugarcane production areas in Mainland China (Guangxi, Yunnan, Guangdong, Hainan, Fujian and Jiangxi provinces). Isolates of the fungus were collected at the six locations. Two molecular techniques were used to compare the DNA of each isolate with the others. Differences were found. When the isolates with similar DNA were grouped together, most isolates in a group were from the same location. Isolates from the same sugarcane variety, but from different locations, were often in different groups based on DNA similarity. The results suggest that breeders test varieties to insure that they are resistant to the population of the fungus from each location where the variety might be grown.
Technical Abstract: Sugarcane smut caused by the fungus Sporisorium scitamineum is found worldwide in sugarcane producing countries and can cause serious loss in stalk yield and sugar quality. In order to reveal the molecular evolution of S. scitamineum, twenty-three S. scitamineum isolates collected from the six primary sugarcane production areas in Mainland China (Guangxi, Yunnan, Guangdong, Hainan, Fujian and Jiangxi provinces) were assessed by RAPD (random amplified polymorphic DNA) and SRAP (sequence-related amplified polymorphism) markers. The results of RAPD, SRAP and RAPD-SRAP combined analyses showed that while the molecular evolution of S. scitamineum was associated with its geographic origin, there was no evidence of a co-evolution mechanism between sugarcane and the pathogen because no close relationship was found between the pathogen and its host origin. The results obtained here not only enrich the research on molecular diversity of S. scitamineum but also provide information needed in sugarcane smut resistance breeding and cultivar distribution. Although race differentiation of S. scitamineum was not detectable at the DNA level by RAPD and SRAP methods, the genetic variation suggests that cultivars intended for distribution to other geographical areas should be tested for susceptibility to S. scitamineum populations in each area.