DISEASE CONTROL THROUGH THE ENHANCEMENT OF RESISTANT SUGARCANE GERMPLASM
Location: Sugarcane Research Unit
Title: Susceptibility of Saccharum spp. and near relatives to mosaic viruses
Submitted to: American Society of Sugar Cane Technologists
Publication Type: Abstract Only
Publication Acceptance Date: April 10, 2012
Publication Date: July 15, 2012
Citation: Grisham, M.P., Hale, A.L. 2012. Susceptibility of Saccharum spp. and near relatives to mosaic viruses. Journal of the American Society of Sugar Cane Technologists. 32:82. Available: http://www.assct.org//. Also published in Sugar Journal 75(1):16-17.
A collection of Saccharum spp., Erianthus, and Miscanthus maintained at the USDA-ARS, Sugarcane Research Unit in Houma, LA (SRU) is an important source of germplasm for the sugarcane improvement program, as well as, for the development of bioenergy feedstock. Interspecific hybrids of Saccharum spp. and, to a limited extent, intergeneric hybrids have resulted in improved commercial sugarcane varieties throughout the world. In addition to the taxonomic diversity of the accessions, they were collected from diverse geographical regions. As the geographical range of sugarcane and bioenergy feedstock expands, susceptibility to viral diseases will affect not only their productivity, but, if grown in proximity to other graminaceous crops, provide a source of virus pathogens that can infect crops such as maize, sorghum, sugarcane, rice, forages, and small grains. Eighty-four accessions (10 S. officinarum, 42 S. spontaneum, 10 S. barberi, seven S. sinense, one S. robustum, six Erianthus, and eight interspecific hybrids of uncertain parentage) that had not been previously screened for mosaic resistance were mechanically inoculated with the two viruses that cause sugarcane mosaic, Sugarcane mosaic virus (SCMV) and Sorghum mosaic virus (SrMV). Test plants were divided into two groups each containing from two to 12 plants per accession. One group was inoculated with SCMV and the other with SrMV. Plants were inoculated three times at two week intervals and observed for the development of mosaic symptoms for six weeks after the final inoculation. Visual observations were verified with polymerase chain reaction (PCR) analysis. Two accessions of S. officinarum, Fiji 47 and La Stripe, were susceptible to both SCMV and SrMV, while Oi Dang was susceptible to SCMV only. Among the S. spontaneum accessions, MPTH98-388 was susceptible to both viruses, while S66-121A, Spont 17, and Spont 24 were susceptible to SrMV only. Three S. barberi accessions, Dhaula, Panura, and Newra, were susceptible to both viruses; likewise, two accessions of S. sinense, China, Katha, were susceptible to the two mosaic viruses. The S. robustum accession, NG77-055, was susceptible to SrMV only. The six Erianthus accessions and eight interspecific hybrids were not susceptible to either SCMV or SrMV. This collection of accessions are currently being utilized in SRU’s Basic Breeding Program to introgress economically important traits including, mosaic resistance, into commercial sugarcane cultivars.