sdu faculty of forestry journal special edition 2009 - Orman Fakültesi

SDÜ ORMAN FAKÜLTESİ DERGİSİ
MEA for possible fungal presence. The most frequent fungus isolated was E.
parasitica which represented 54.8% of all isolates. The second most frequent
organisms isolated from discolored wood were bacteria (27.6% of all isolates).
17.6% of all isolates were represented by 25 macroscopically different species of
fungi among which were Cladosporium cladosporioides (Fresen.) G.A. de Vries,
Mucor circinelloides Tiegh., Umbelopsis vinacea (Dixon-Stew.) Arx, Armillaria
spp., Nectria spp., Pestalotia spp., Fusarium spp., and Pythium spp.
The controls were made by cultivating 74 boring chips that were taken from
healthy wood. The result of this test was that 65 of the isolations were sterile and
only 9 Petri dishes were populated by bacteria and three different genera of fungi.
No E. parasitica was present in controls.
Dried healthy wood was present quite often at the center of the canker or near
the margin of canker. 64 isolations were made for testing for the presence of E.
parasitica in this area of the wood. After a month of incubation almost all
isolations were negative and only seven had bacteria.
As part of testing for the presence of E. parasitica in different parts of the
wood, 420 isolates were made from the canker margin in the wood. E. parasitica
was also the dominant fungus here (58.6%). The second most frequently found
were bacteria. 23.6% of isolates contained eight macroscopically different fungi.
17.9% of samples were sterile.
3.5. Growth in pure culture
Average radial growth in pure culture at room temperature of about 25°C is
reported to be about 20 mm in seven days (Davidson and Lorenz, 1938). We
measured the growth rate of 45 pure cultures on 1.5% (w/v) MEA at 24°C; 1712
measurements were made. The average radial growth per day was 2.4 mm (± 0.1
mm at 95% confidence level). The slowest measured average radial growth was 0.9
mm per day and the fastest was 5.6 mm per day.
3.6. Density of perithecia and ascospore discharge
When measuring the area of the canker, three different densities of perithecia
were determined (Table 2). The low density perithecia ranged from 181 to 210
perithecia cm –2 with an average of 196 perithecia cm –2 . The middle density ranged
from 234 to 269 perithecia cm –2 with an average of 255 perithecia cm –2 . The high
density ranged from 301 to 378 perithecia cm –2 with an average of 348 perithecia
cm –2 . These average densities of perithecia were used for calculating the number of
perithecia at the whole canker level and the total ascospore production per canker.
The total number of perithecia per whole canker could be from 25,000 for young
cankers to over 2,102,000 perithecia for old cankers. The average number of
peritecia per canker was 647,000 for the 23 Eutypella cankers analyzed. It should
be noted that not all of these perithecia discharged ascospores because some of
them were still developing, while others were too old and empty. The maturity test
was performed on those samples that were used in the study of ascospore
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