title: Development and Comparison of TaqMan-Based Real-Time PCR Assays for Detection and Differentiation of Ralstonia solanacearum strains.
abstract: Bacterial wilt caused by Ralstonia solanacearum is destructive to many plant species worldwide. The race 3 biovar 2 (r3b2) strains of R. solanacearum infect potatoes in temperate climates and are listed as select agents by the U.S. government. TaqMan-based real-time quantitative PCR (qPCR) is commonly used in federal and state diagnostic laboratories over conventional PCR due to its speed and sensitivity. We developed the Rs16S primers and probe set and compared it with a widely used set (RS) for detecting R. solanacearum species complex strains. We also developed the RsSA3 primers and probe set and compared it with the previously published B2 and RsSA2 sets for specific detection of r3b2 strains. Both comparisons were done under standardized qPCR master mix and cycling conditions. The Rs16S and RS assays detected all 90 R. solanacearum species complex strains and none of the five outgroups, but the former was more sensitive than the latter. For r3b2 strain detection, the RsSA2 and RsSA3 sets specifically detected the 34 r3b2 strains and none of the 56 R. solanacearum non-r3b2 strains or out-group strains. The B2 set, however, detected five non-r3b2 R. solanacearum strains and was less sensitive than the other two sets under the same testing conditions. We conclude that the Rs16S, RsSA2, and RsSA3 sets are best suited under the standardized conditions for the detection of R. solanacearum species complex and r3b2 strains by TaqMan-based qPCR assays.
authors.affiliation: Floral and Nursery Plants Research Unit, Agricultural Research Service, United States Department of Agriculture, United States National Arboretum, Beltsville, MD, USA.|Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Stulberg
authors.affiliation: Center for Plant Health Science and Technology, United States Department of Agriculture, Plant Protection and Quarantine, Animal and Plant Health Inspection Service, Beltsville, MD, USA.
authors.forename: John
authors.initials: J
authors.lastname: Rascoe
authors.affiliation: Center for Plant Health Science and Technology, United States Department of Agriculture, Plant Protection and Quarantine, Animal and Plant Health Inspection Service, Beltsville, MD, USA.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Li
authors.affiliation: Center for Plant Health Science and Technology, United States Department of Agriculture, Plant Protection and Quarantine, Animal and Plant Health Inspection Service, Beltsville, MD, USA.
authors.forename: Zonghe
authors.initials: Z
authors.lastname: Yan
authors.affiliation: Center for Plant Health Science and Technology, United States Department of Agriculture, Plant Protection and Quarantine, Animal and Plant Health Inspection Service, Beltsville, MD, USA.
authors.forename: Mark K
authors.initials: MK
authors.lastname: Nakhla
authors.affiliation: Floral and Nursery Plants Research Unit, Agricultural Research Service, United States Department of Agriculture, United States National Arboretum, Beltsville, MD, USA. qi.huang@ars.usda.gov.
authors.forename: Qi
authors.initials: Q
authors.lastname: Huang
mesh_terms: D015373:Bacterial Typing Techniques / Q000295:instrumentation / Q000379:methods*; D017931:DNA Primers / Q000235:genetics; D010935:Plant Diseases / Q000382:microbiology*; D043368:Ralstonia solanacearum / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D060888:Real-Time Polymerase Chain Reaction / Q000295:instrumentation / Q000379:methods*; D011198:Solanum tuberosum / Q000382:microbiology*
chemical_list: D017931:DNA Primers