UP‐PCR Genotyping and rDNA Analysis of Ascochyta pisi Lib

Isolates of Ascochyta pisi, previously identified as separate pathotypes, were genotyped by rDNA‐RFLP and UP‐PCR using 8 UP‐primers and 2 arbitrary primers individually or in pair‐wise combinations. The appearance of polymorphic UP‐PCR products for all studied isolates facilitated their differentiation. The markers were suitable in identifying isolates, and may be useful for developing isolate‐ or pathotype‐specific PCR‐based diagnostic assays. In studying genetic relatedness by UP‐PCR among A. pisi isolates, two distinct clusters were revealed. rDNA analysis of the isolates based on endo‐ntjclease digestion of amplified ITSl and 1TS2‐25S nuclear rDNA regions did not separate the isolates, whereas the variabihty of the isolates using UP‐PCR was more than 40%.