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 experiment was established at Hof Steimke, DSV (Deutschen Saatveredelung), Germany. The ecotypes originated from the Polish Gene Bank, IHAR – Botanical Garden, 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 susceptible group. Thirty‐three (7.4%) ecotypes were more resistant and 29 (6.5%) ecotypes had resistance on the level of the most resistant control variety Ottos (score of resistance 5.3). Eight ecotypes (1.8%) with the highest level of resistance (score 7 or higher) were identified as especially promising 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 on average 7 or 7.5. For 17 different habitats from which the tested ecotypes were collected only those ecotypes originating from 10 habitats (meadow, peat meadow, forest meadow, pasture, field, lakeside, waterside, ditch, roadside and gravel pit) showed high levels of resistance to rust. The value of newly identified resistant ecotypes for control of rusts on Kentucky bluegrass is discussed. Erste Untersuchungen über die Resistenz polnischer Ökotypen des Wiesenrispengrases gegen Rostkrankheiten Vierhundertvierundvierzig in Polen gesammelte Ökotypen des Wiesenrispengrases (Poa pratensis L.) wurden hinsichtlich ihrer Rostresistenz geprüft. Auf Hof Steimke, DSV (Deutsche Saatveredelung), Deutschland, wurde ein Feldversuch angelegt. Die Ökotypen stammten von der polnischen Genbank, IHAR – Botanischer Garten Bydgoszcz. Zweiundsechzig Ökotypen (13,9%) wiesen durchschnittliche Boniturwerte > 5 auf und wurden zu einer Gruppe mit hoher Resistenz zusammengefaßt. Ökotypen mit durchschnittlichen Boniturwerten