Parasitic Specialization of Puccinia graminis f. sp. avenae in Israel During 1971-1977. J. Manisterski, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel. Plant Dis. 71:842-844. Accepted for publication 22 January 1987. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-0842.

The oat stem rust disease caused by Puccinia graminis f. sp. avenae occurs annually in Israel on the wild species Avena sterilis, the putative progenitor of cultivated oats, which is of countrywide distribution. The disease also attacks cultivated oats grown on a limited acreage. A total of 895 fungal isolates collected mainly from A. sterilis in 16 regions during seven successive years were studied for racial identity. The oat rust populations consisted of 12 physiologic races. Races 72 and 8 were the most common. Some shift over the years in the relative prevalence of race 8 that could not be ascribed to changes in oat cultivation was recorded. Two new races, never reported previously, were identified. One race is virulent only on the cultivar Saia and was tentatively designated as 1S. The other one is virulent on the hosts with Pg1, Pg3, and Pg9, resembling races 61 and 80 and designated here as 7HF.