Genetic relatedness among and within different Rhizoctonia solani anastomosis groups as assessed by RAPD, ERIC and REP-PCR

The genetic relatedness among 41 isolates of Rhizoctonia solani belonging t o 11 AGs was assessed based on the fragment pattern analysis obtained by th e amplification of genomic DNA by 3 RAPD primers (P14, R28 and RC09), ERIC (ERICIR-I/ERIC2) and REP (REP1R-I/REP2-I) gene sequences. Based on the band ing patterns of PCR-amplified products, seven putative groups among the 41 isolates were recognized. RAPD-PCR generated multiple distinct products sho wing considerable variability among the isolates of different AC types. Iso lates originated from the same geographical origin or host plants were not always genetically related. Amplification with ERIC and REP elements enable d detection of AGs/subgroup-conserved and isolate-polymorphic variants, res pectively. Though pattern types generated by ERIC and REP in general, were distinctly variable among different subgroups, less variable fingerprint pa tterns were produced within the isolates of each subgroup.