sdu faculty of forestry journal special edition 2009 - Orman Fakültesi

SDÜ Faculty of Forestry Journal
proven to be D. scrobiculata (Hausner et al., 1999). Blodgett and Stanosz (1999)
did demonstrate the ability of well-characterized isolates of D. pinea and D.
scrobiculata to kill shoots of small, potted Colorado blue spruce seedlings
following wounding and inoculation in a greenhouse experiment. But the relative
lack of reports of damage to spruces, even when grown in the same locations where
more susceptible species are attacked (e.g., red pine in the Great Lakes region of
the USA) suggests that spruce species are infrequent hosts, or perhaps not often
severely damaged by D. pinea. Unambiguous identification of the Diplodia
species associated with disease symptoms of spruces should allow a better
understanding of the relationships between these fungi and Picea species.
Regardless of possible ambiguity in the status of D. pinea as a potential
pathogen of spruce, galls of the Cooley spruce gall adelgid serve as a substrate.
The production of a very large number of conidia on any individual gall is
magnified by the potential for a single spruce crown to bear many hundreds of
galls. This utilization of galls by D. pinea to produce very large numbers of
conidia confirms that, in the absence of normal disease development, altered
tissues on an atypical host tree species can be a potentially significant reservoir
inoculum source for this pathogen.
4. ACKNOWLEDGMENTS
The authors thank Erin Brooks for collecting the galls used in this study, and
with Mary Lynn Stanosz, for assistance examining galls in the laboratory.
5. REFERENCES
Audley, D. E., Skelly, J. M., 1994. A Phomopsis species associated with nonlethal adelgid galls on
upper crown branchlets of red spruce in West Virginia. Plant Disease 78, 569-571.
Blodgett, J. T., Stanosz, G. R., 1999. Differences in aggressiveness of Sphaeropsis sapinea RAPD
marker group isolates on several conifers. Plant Disease 83, 853-856.
Brookhouser, L. W., Peterson, G. W., 1971. Infection of Austrian, Scots, and ponderosa pines by
Diplodia pinea. Phytopathology 61, 409-414.
Chou, C. K. S., 1976. A shoot dieback in Pinus radiata caused by Diplodia pinea. I. Symptoms,
disease development, and isolation of the pathogen. New Zealand Journal of Forest
Science 6, 72-79.
Chou, C. K. S., 1978. Penetration of young stems of Pinus radiata by Diplodia pinea. Physiological
Plant Pathology 12, 189-192.
Chou, C. K. S., 1987. Crown wilt of Pinus radiata associated with Diplodia pinea infection of
woody stems. European Journal of Forest Pathology 17, 398-411.
Cumming, M. E. P., 1959. The biology of Adelges cooleyi (Gill.) (Homoptera: Phylloxeridae).
Canadian Entomologist 91, 601-617.
90