Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 4/19/1997
Publication Date: N/A
Technical Abstract: The molecular taxonomy of D. phaseolorum var. caulivora (DPC), D. p. var. meridionalis (DPM), D. p. var. sojae (DPS), and P. longicolla (PL) from soybean was analyzed by polymerase chain reaction-restriction fragment length polymophisms (PCR-RFLP) using 50 isolates and the DNA sequence of the internal transcribed spacer (ITS) regions from 28 isolates. After digestion with four restriction enzymes, isolates within DPC, DPM, and PL had uniform banding patterns; while isolates within DPS had 10 different banding patterns. Sequence comparisons showed that there was minimum variation in the ITS1 and ITS2 regions among isolates within DPC, DPM, and PL. DPS isolates were separated in different groups. Culture characteristics including types of fruiting bodies and conidia were also assessed for all isolates. The molecular taxonomic analysis matched the traditional speciation of Diaporthe/Phomopsis, and showed that the genetic background of DPS is complex and may represent distinct taxonomic groups.