sdu faculty of forestry journal special edition 2009 - Orman Fakültesi

SDÜ Faculty of Forestry Journal
also was filtered. The filter for each gall was examined with the aid of a microscope
for presence or absence of conidia recognized as those of D. pinea based on
morphological characteristics. For three randomly selected galls from each branch,
conidia were counted in five compound microscope fields randomly located within the
filtered area at magnifications of 40 to 200x. Lower magnification was used for filters
with relatively few conidia and higher magnification (i.e., smaller fields) was used for
filters with many conidia. The number of conidia in five fields was multiplied by
respective factors to adjust for total filtered area. Galls were then oven dried and
weighed to also allow expression of conidial numbers on the basis of oven dry weight
(odw).
To confirm pathogen identity, 12 filters (corresponding to four galls from each third
of the tree crown) on which numerous conidia had been deposited were selected. A
piece of the filter approximately 5 mm x 5 mm was excised and placed in a
microcentrifuge tube. This was ground and then DNA was directly extracted using
methods described by Smith and Stanosz (1995). DNA was amplified using speciesspecific
primers developed by Smith and Stanosz (2006) that allow differentiation of
D. pinea from the similar conifer pathogen D. scrobiculata.
3. RESULTS AND DISCUSSION
Every gall yielded conidia morphologically consistent with those of D. pinea,
although the estimated numbers of conidia obtained varied widely. The range per gall
was from 176 to 1,099,695 (mean = 249,599, standard error = 57,756). The range per
gram odw was from 169 to 3,447,320 (mean = 462,691, standard error = 120,975).
The numbers of galls categorized according to the estimated numbers of conidia
extracted from each (for the 36 for which conidia were quantified) are displayed in
Figure 2. For the majority of galls, this number was >10 4 conidia on both per gall and
per gram odw bases.
Figure 2: Numbers of Cooley spruce gall adelgid galls categorized by the
estimated number of conidia extracted per gall.
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