Location: National Germplasm Resources LaboratoryTitle: Natural infection of Sorghum bicolor germplasm by Sugarcane yellow leaf virus in Florida Author
Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 3/26/2017
Publication Date: 12/1/2017
Citation: Boukari, W., Wei, C., Mulandesa, E., Hincapie, M., Mollov, D.S., Beiriger, R., Rott, P. 2017. Natural infection of Sorghum bicolor germplasm by Sugarcane yellow leaf virus in Florida. Phytopathology. S5:137. Interpretive Summary:
Technical Abstract: Sugarcane yellow leaf virus (SCYLV), the causal agent of sugarcane yellow leaf, is vectored by the aphid Melanaphis sacchari. Although sugarcane is the primary host of SCYLV, two new natural hosts were recently identified in Florida: the weed Columbus grass (Sorghum almum) and grain sorghum (Sorghum bicolor). Most sugarcane varieties grown in Florida are susceptible to infection by SCYLV, and resistance to this virus seems limited in sugarcane germplasm. We investigated the resistance of S. bicolor germplasm to infection by SCYLV. A field trial comprising 30 different sorghum lines was established at Belle Glade, FL in spring 2016. The planted crop produced 25 lines that were colonized by M. sacchari, whereas only 11 lines grew and were colonized by the aphids when ratooned. In the plant crop, out of 10 plants sampled per line, 4 to 10 tested positive for SCYLV by tissue-blot immunoassay (TBIA). In the ratoon crop, out of 10 plants sampled per line, 5 to 10 tested positive. However, SCYLV was found in only 4 out of 11 TBIA positive plants from ratoon crop by reverse transcription-polymerase chain reaction (RT-PCR). Disparity between TBIA and RT-PCR results suggest either serological cross-reactivity with an unknown virus or the presence of new genetic variants of SCYLV. This needs to be resolved before further screening of grain sorghum resistance to SCYLV is performed for potential use of sorghum resistance in sugarcane breeding and marker-assisted selection.