Preliminary observations on resistance to rust diseases of Kentucky bluegrass ecotypes from Poland

Four hundred and forty-four ecotypes of Kentucky bluegrass (Poa pratensis L .) collected from Poland were screened for rust resistance. A field experim ent was established at Hof Steimke, DSV (Deutschen Saatveredelung), Germany . The ecotypes originated fi om the Polish Gene Bank, IHAR - Botanical Gard en, Bydgoszcz. Sixty-two (13.9%) ecotypes that scored on average more than 5 were included in a group with high resistance. Ecotypes scored on average less than 5 were either included in a susceptible group (average scores 4. 0-4.9) or a very susceptible group (average scores 2.0-3.9). There were 181 ecotypes in the susceptible group (40.8%) and 201 (45.3%) in the very susc eptible group. Thirty-three (7.4%) ecotypes were more resistant and 29 (6.5 %) ecotypes had resistance on the level of the most resistant control varie ty Ottos (score of resistance 5.3). Eight ecotypes (1.8%) with the highest level of resistance (score 7 or higher) were identified as especially promi sing sources of rust resistance. One ecotype (141858) showed reaction type 9 in both years and another one (141903) showed reaction type 9 in one year and reaction type 8 in another year (mean 8.5). Six ecotypes were scored o n average 7 or 7.5. For 17 different habitats from which the tested ecotype s were collected only those ecotypes originating from 10 habitats (meadow, peat meadow, forest meadow, pasture, field, lakeside, waterside, ditch, roa dside and gravel pit) showed high levels of resistance to rust. The value o f newly identified resistant ecotypes for control of rusts on Kentucky blue grass is discussed.