MOLECULAR CHARACTERIZATION OF AMPELOMYCES SPP. USING RAPD AND ISSR MARKERS AGAINST OKRA (ABELMOSCHUS ESCULENTUS (L.) MOENCH) POWDERY MILDEWS. Sundaramoorthy, K. Athira, P. Sivasakthivelan and J. Johnny Subakar IvinAbstract A survey was conducted in major okra growing districts of Tamil Nadu during June 2021 to assess the incidence of powdery mildew and to collect different isolates of A. quisqualis. Ten isolates of Ampelomyces were collected and these were tentatively identified as A. quisqualis using specific primer pair for A. quisqualis. We have used 5 random amplified polymorphic DNA (RAPD) markers to estimate the genetic variation among the 10 isolates of Ampelomyces spp. A dendrogram was constructed based on Jaccardâs similarity coefficient using the marker data from the A. quisqualis isolates with unweighted pair group method (UPGMA). Analysis of these polymorphisms revealed 4 distinct groups, in agreement with previous studies. The minimum similarity index was recorded at 20 per cent between TNAU-AQ104 and TNAU-AQ107 even though they were from same cluster group, thus confirming that the Ampelomyces isolates from entirely different geographical areas can also share some genetic relationship. The ISSR analysis based on the dendrogram results also revealed that the ten isolates showed 20 to 85 percent similarity coefficient. This result indicated the identification patterns of Ampelomyces spp. |