First Report of Sphaeropsis sapinea on Aleppo Pine in Israel. Z. Madar, Department of Plant Pathology, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel. M. Kimchi, and Z. Solel, Department of Plant Pathology, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel. Plant Dis. 80:343. Accepted for publication 10 January 1996. Copyright 1996 The American Phytopathological Society. DOI: 10.1094/PD-80-0343A.
Dieback of shoots and branches of Aleppo pine (Pinus halepensis Mill.) trees was observed 1n several pine plantations in Israel in the summer of 1995. The needles of affected current season branches turned reddish brown. Many of the shoots were bent near the tip. Pycnidia were present mainly on opened cones, as well as on dead branches and needles. Isolations made from the apex of affected shoots and from discolored branches of both young and mature trees, yielded colonies of Sphaeropsis sapinea (Fr.:Fr.) Dyko & Sutton in Sutton. All the isolates had fluffy gray-green mycelium, and thus appear to be morphotype A, as described by Palmer et al. (I). The pathogenicity of several isolates of S. sapinea was tested by inoculating 2-year-old seedlings of Aleppo pines. The inoculations were made by removing the outer bark and placing a 3-mm disk of a culture of S. sapinea over the exposed tissue. The inoculated area was covered with wet cotton and wrapped with plastic ribbons. After 3 weeks distinctive sunken cankers were observed. Both the affected bark and the xylem underneath had brown coloration. The pathogen was identified by the conidia formed within the black pycnidia. One-celled conidia of. S. sapinea were predominant but two-celled spores were common; three-celled spores occurred rarely. The mean conidial dimensions, based on measurements of 100 spores, collected from naturally infected tissue, was 30.0 x 14.8 µm; the extreme range was 26.6 to 35.8 x 13.3 to 15.8 µm. The isolates of S. sapinea from pine were nonpathogenic to Italian cypress (Cupressus sempervirens L.). Aleppo pine grown in semiarid regions is already known as a host of this cosmopolitan pathogen, especially under water stress.Reference: (I) M. A. Palmer et al. Phytopathology 77: 944. 1987.