journal of forest science

Table 3. The electrolyte leakage from tap root in different intervals
after desiccation stress
Time interval after REL (%)
desiccation test 24 h–15%/25°C Duncan
Directly after stress 24 A
3 weeks after stress 20 B
5 weeks after stress 18 B
2 months after stress 24 A
α ***
R2 0.23
***P < 0.001 (means followed by the same letter are not significantly
different)
leakage was studied. After stress (frost and desiccation)
planting stock was stored in climatic room for a different
time and the rate of electrolyte leakage was measured.
The electrolyte leakage decreased in parallel with time
and after 2 months it was lower by 100% than directly
after frost treatment (Table 2).
On the other hand, the electrolyte leakage decreased
with time factor after desiccation treatment too, but there
was not a rapid fall, and after two months the REL-values
were the same as directly after stress (Table 3).
The influence of different ways of autoclaving and
interval of second measurement on electrolyte leakage
These results did not show any marked differences in
leakage between the intervals of autoclaving. Equally, the
interval of second measurement did not play a big role in
the rate of electrolyte leakage either (Table 4).
Electrolyte leakage after stress treatment of the same
intensity on different dates
On three different dates, the cold test (2h/0°C) was realized
with bare-rooted oak planting stock. The lowest
values of REL (12%) were observed on 10. 11. 1997
(Table 5). Similarly, a desiccation test was carried out
(4h – 15% air humidity/25°C) and following the stress
treatments electrolyte leakage was measured. The highest
EL was observed on 3. 6. 1998 (Table 6).
DISCUSSION
Electrolyte leakage at different intervals after stress
treatments
The aim of the first part of this study was to examine
the influence of different time intervals after stress treat-
Table 4. The electrolyte leakage from tap root after different time
intervals of autoclaving and time of second measurement
Duration of auto- REL (%) second measurement after
claving (min) 24 h 48 h 72 h
10 16 14 14
20 16 15 13
40 14 15 13
Table 5. The electrolyte leakage from tap root after cold stress
on different dates
Date REL (%)
2 h/0°C Duncan
10. 11. 1997 12 C
11. 5. 1998 14 B
3. 6. 1998 18 A
α ***
R2 0.51
***P < 0.001 (means followed by the same letter are not significantly
different)
ments on the rate of electrolyte leakage after stress factors.
After stress treatments, the plants were cold stored and
the electrolyte leakage was lower by 100% after two
months than directly after frost stress. The analysis of
the values of electrolyte leakage showed that absolute
values after autoclaving were similar and values of the
Fig. 1. Browning of oak root tissue three weeks after frost stress
first measurement changed during time. This fact can signal
that injured cell membranes were closed during cold
storage because REL values after autoclaving were the
same. On the other hand, after desiccation treatment the
REL values two months after stress were the same as directly
after stress. Although the REL values two months
after frost treatment were the same as for unstressed
plants, it was possible to detect the root damage on the
Table 6. The electrolyte leakage from tap after desiccation test
in different dates
Date REL (%)
4 h–15%/25°C Duncan
1. 4. 1998 12 C
11. 5. 1998 16 B
28. 10. 1997 18 A
3. 6. 1998 20 A
α ***
R2 0.36
***P < 0.001 (means followed by the same letter are not significantly
different)
J. FOR. SCI., 47, 2001 (7): 301–306 303