Morfologia i wybrane cechy fizjologiczne patogenów Phytophthora cactorum (Lebert et Cohn) Schröter i Phytophthora citricola Sawada występujących w szkółkach leśnych w południowej Polsce
AbstractThe studies covered thirteen isolates of Phytophthora cactorum from the seedlings of Abies alba Mill., Acer pseudoplatanus L., Alnus glutinosa (L.) Gaertn., A. incana (L.) Moench., Betula pendula Roth., Fagus sylvatica L., Pinus nigra J.F. Arnold and P. sylvestris L., and four isolates of P. citricola from the seedlings of F. sylvatica, Picea abies (L.) H. Karst and P. sylvestris. The seedlings showing symptoms of damping-off were collected during 2000-2003 in eight forest nurseries located in the South of Poland. The following characteristics of the isolates were determined: colony morphology on potato dextrose agar (PDA), corn meal agar (CMA) and V-8 juice agar (V-8) media; dimensions and types of the reproduction structures (oogonia, antheridia, oospores and sporangia); optimum, minimum and maximum temperatures of growth on PDA medium; sensitivity to hymexazol, a component of selective media for the isolation of Phytophthora spp. from plant tissues and from soil; pathogenicity to Alnus glutinosa, Betula pendula, Fagus sylvatica, Picea abies, Pinus nigra and P. sylvestris seedlings in the seedling inoculation test. The isolates of P. cactorum differed in the dimensions of oogonia and oospores, and in the dimensions and morphology of sporangia. Such differences were also found in the isolates of P. citricola. No connection was observed between the features of isolates and their host plant or a nursery. The colony morphologies of P. cactorum isolates grown on PDA, CMA and V-8 media were similar. A greater morphological diversity was found in the isolates of P. citricola. Both species showed a slight variation in the optimum, minimum and maximum temperatures of growth between isolates. The isolates of P. cactorum distinctly differed in the sensitivity to hymexazol, while those of P. citricola displayed an inconsiderable variation. Hymexazol more strongly reduced the growth rate of colonies in P. cactorum than in P. citricola. The greater sensitivity of P. cactorum may limit the efficiency of its isolation from plants and soil on hymexazol-containing media. In the seedling inoculation test, beech (Fagus sylvatica) seedlings appeared to be particularly susceptible to the infection with P. cactorum and P. citricola. The least susceptible tree species to the infection with the former was Norway spruce (Picea abies), and with the latter, common alder (Alnus glutinosa). Phytophthora citricola was more aggressive than P. cactorum towards the seedlings of Austrian pine (Pinus nigra), Scots pine (Pinus sylvestris) and Norway spruce, whereas both pathogens showed a similar aggressiveness towards the seedlings of beech, common alder and silver birch (Betula pendula). The isolates of P. cactorum and P. citricola obtained from various host plants differed in pathogenicity to the seedlings of beech, silver birch, common alder, Norway spruce, Austrian pine and Scots pine, but they did not show host specificity. This indicates that the occurrence of both pathogens in the soils of forest nurseries may pose a threat to various plants introduced there in successive stages of crop rotation.
|Other language title versions||Morphology and some physiological characteristics of Phytophthora cactorum (Lebert et Cohn) Schrater and Phytophthora citricola Sawada occurring in forest nurseries in southern Poland|
|Publisher||Uniwersytet Rolniczy im. Hugona Kołłątaja w Krakowie, MNiSW |
|Publishing place (Publisher address)||Kraków|
|Book series /Journal (in case of Journal special issue)||Zeszyty Naukowe Uniwersytetu Rolniczego im. Hugona Kołłątaja w Krakowie. Rozprawy, ISSN 1899-3486, (0 pkt)|
|Publication size in sheets||5|
* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.