PL
Celem prowadzonych badań była izolacja, identyfi kacja oraz ocena chorobotwórczości czynnika powodującego zamieranie nasadzeń Ajuga reptans w szkółkach bylinowych. Z roślin z objawami zgnilizny podstawy pędu oraz korzeni, jak również z podłoża izolowano Phytophthora cryptogea. Identyfi kację patogena przeprowadzono w oparciu o cechy morfologiczne oraz stosując technikę PCR ze starterami gatunkowo specyfi cznymi. W warunkach laboratoryjnych omawiany gatunek kolonizował liście, ogonki liściowe i korzenie A. reptans ‘Multicolor’, powodując na nich rozwój zgnilizny. Ponadto badany izolat zasiedlał tkanki 5 odmian w obrębie gatunku A. reptans oraz gatunku mieszańcowego, powszechnie uprawianych w kontenerowych szkółkach roślin ozdobnych. Najbardziej podatna na P. cryptogea okazała się odmiana ‘Braunherz’. Doświadczenia nad wpływem temperatury na rozwój patogena wykazały, iż rozwijał się on w zakresie od 5ºC do 30ºC, przy optimum 25ºC.
EN
Yearly observation of plant healthiness in Polish container nurseries indicates on systematically growing list of host plants for Phytophthora species, one of the most dangerous soilborne pathogens. In 2011, in one of the perennial nursery, symptoms of stem base and root rot on Ajuga reptans were observed. Necrosis progressivly spread on leaf blades. The objective of this study was isolation, identifi cation, morphological characterization and pathogenicity evaluation of the disease factor. Plant samples together with substratum were transferred in plastic bags to the laboratory. After washing in running tap and distilled water and sterilising over a burner fl ame, about 5 mm parts, taken from the border of healthy and diseased tissues, were put onto PDA medium. Cultures growing around inocula were at fi rst identifi ed to the genus on the base of microscopic observation. For pathogen isolation from the substratum baiting technique with rhododendron leaves was used. In the laboratory conditions pathogenicity tests were performed. On roots, leaf blades and leaf petioles parts laying in a trays on sterile, blotting paper covered with plastic net pathogen inocula were transferred. During 6 days incubation necrosis development was observed. From infected plants’ tissues as well as from substratum Phytophthora cryptogea Pethybr. & Laff. was isolated. The pathogen was identifi ed on the basis of morphological and cultural characteristics. Results were confi rmed using PCR technique with species-specifi c primers. The trials on the infl uence of temperature on the pathogen growth showed that P. cryptogea developed at temperatures from 5oC to 30oC, with the optimum at 25oC. In the laboratory trials pathogenicity of P. cryptogea to A. reptans ‘Multicolor’ organs was confi rmed. Additionally, the susceptibility of different Ajuga species and cultivars was examined. The pathogen colonized 5 cultivars among A. reptans as well as A. x tenorii, commonly growing in ornamental nurseries. The most susceptible was cv. Braunherz. To fulfi ll Koch’s postulates, after completed trials, from plant tissues with disease symptoms the pathogen was reisolated and again identifi ed as P. cryptogea.