No abstract

Three similar isolates of Phytophthora (Phytophthora sp-h) were obtained from diseased Spathiphyllum and Primula plants. Cultural characteristics did not fit any known description of Phytophthora species. The Phytophthora sp-h isolates are papillate, are homothallic, possess 80 to 86% amphigynous antheridia, and have a maximum temperature for growth of 36.5 degrees C. Isozyme analysis of the Phytophthora sp-h isolates revealed a three-banded pattern with malic enzyme and a three-banded pattern with malate dehydrogenase on the second putative locus. The fastest band at both enzyme loci comigrated with the single P. nicotianae band, the slowest band comigrated with the single P. cactorum (and also P. pseudotsugae) band, and one band in between was concluded to represent the heterodimeric isozyme. The random amplified polymorphic DNA patterns of the Phytophthora sp-h isolates almost exclusively consisted of bands that were also present in either P. nicotianae or P. cactorum. Southern hybridization showed that bands specific for P. nicotianae were present as comigrating bands in the Phytophthora sp-h isolates. The same was found for species-specific bands of P. cactorum. It is concluded that the three Phytophthora sp-h isolates represent interspecific hybrids, P. nicotianae being the one parent and P. cactorum the other. Analysis of mito-chondrial DNA with restriction enzymes revealed banding patterns in all the Phytophthora sp-h isolates identical with those of P. nicotianae, confirming that indeed P. nicotianae was one of the parents.

No abstract

Root and crown rot of raspberry (Rubus idaeus L.) was observed in a plantation at the experimental station of small fruits in Kostinbrod, Bulgaria. Isolates of Phytophthora spp. were obtained from diseased plants. Colony morphology, growth rates, features of asexual and sexual structures were studied and as a result two Phytophthora species were identified: Phytophthora citricola Saw. and Phytophthora eitrophthora (R.E. Sm. & E,H. Sin.)Leonian. Their pathogenicity was confirmed in artificial inoculation experiments. The isozyme (o~-esterase) patterns ofP citrophthora and P. citricola isolates from raspberry and from the collection of the CBS, Baarn the Nether/ands were compared, using micro-gel electrophoresis. Both species are reported for the first time as pathogens of raspberry in Bulgaria. This is only the second report in phytopathological literature of P. citrophthora on raspberry, the first being from Chile [Latorre and Munoz, 1993].

No abstract