Seedling blight of Glycyrrhiza uralensis caused by Pythium myriotylum, P. aphanidermatum and P. spinosum and identifying primary inoculum sources using multiplex PCR detection.

Pythium species, isolated from seedlings of Glycyrrhiza uralensis with blight, were identified as P. myriotylum, P. aphanidermatum, and P. spinosum on the basis of morphological characteristics and sequences of the internal transcribed spacer regions of rDNA. In pathogenicity tests, the isolates of the three Pythium species caused blight, producing the original disease symptoms. The primary inoculum source was determined using a multiplex PCR to detect the pathogen. All the Pythium species were detected in the soils of fields with the diseased plants and in soils of adjacent field soils. [ABSTRACT FROM AUTHOR]