1Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, AB, Canada, T6G 2P5
2National Research Centre on Plant Biotechnology, Indian Agricultural Research Institute, New Delhi 110 012, India
3Agriculuture and Agri-Food Canada, Research Centre, PO Box 3000, Lethbridge, AB T1J 4B1, Canada
*Corresponding author. E-mail: trsharma@nrcpb.org
Molecular analysis was performed to detect genetic diversity in 106 Rhynchosporium secalis isolates collected from different regions of Canada using random amplified polymorphic DNA (RAPD) markers. The isolates collected from barley cultivars having different resistance specificity to R. secalis and grown in geographically distinct regions, exhibited reproducible variation for 2–3 polymorphic PCR products per decamer primer. Analysis of 1960 RAPD markers data obtained with five primers formed 5 groups with different genetic similarity. High genetic variation was observed in R. secalis isolates obtained from resistant and susceptible cultivars of barley. Isolates collected from susceptible cultivars showed a tendency to group together, whereas isolates from resistant cultivars were divergent. R. secalis isolates infecting different barley cultivars released as resistant to the barley scald formed a specific group with UPGMA, even though all these isolates were collected from the same epidemiological region. Analysis of 15 isolates collected from one resistant cultivar Duke formed three clusters with low bootstrap values indicating high genetic diversity among the isolates present on a single host cultivar.
barley scald, Rhynchosporium secalis, RAPD, genetic variability
