DNA-PROBE SPECIFIC TO RHIZOCTONIA-SOLANI ANASTOMOSIS GROUP-8

A DNA probe was developed which hybridizes strongly with DNAs of all isolates of Rhizoctonia solani anastomosis group 8 (AG-8) tested. The probe hybridized only weakly or not at all with DNA of isolates from other anastomosis groups. The results presented here indicate that the probe recognizes a dispersed repeated DNA element in AG-8 isolates and that genetic variation occurs within AG-8. Preliminary experiments show that the repeated unit is at least 1.8 kbp in length and that sequence variation occurs between different repeat units. The probe has the potential to further our understanding of the population dynamics of bare patch disease in cereal crops.