ARS | Publication request: MOLECULAR AND PATHOLOGICAL CHARACTERIZATION OF RICE SHEATH BLIGHT PATHOGEN ISOLATES FROM ARKANSAS USING RDNA-INTERNAL TRANSCRIBED SPACER SEQUENCES

Submitted to: National American Phytopathology Meetings
Publication Type: Abstract Only
Publication Acceptance Date: March 15, 2002
Publication Date: July 27, 2003
Citation: Singh, P., Jia, Y., Cartwright, R., Lee, F.N., Eizenga, G.C. 2003. Molecular and pathological characterization of rice sheath blight pathogen isolates from arkansas using rDNA-internal transcribed spacer sequences [abstract]. National American Phytopathology Meetings. P-2002-0676-AMA/

Technical Abstract: Rice sheath blight, caused by Rhizoctonia solani Kühn (anastomosis group AG1-IA), is a serious disease worldwide. R. solani has a broad host range and no complete genetic resistance is available among cultivated rices. As first step to identify sheath blight resistance gene(s), molecular characterization of R. solani was performed to identify the most virulent isolate using DNA sequences of the ribosomal internal transcribed spacer (rDNA-ITS). Fourteen R. solani isolates were collected from 10 rice fields in Arkansas during the 2001 growing season. The rDNA-ITS region from these isolates was amplified by PCR, cloned, and sequenced. Resulting sequences were analyzed using Informax Vector NTI Suite V.6 and their phylogenetic relationship was established. To date, three genetically distinct classes of the pathogen were discovered. Progress in pathological characterization of these isolates will be presented.