ЭлБиб

recorded ni

room

temperature with an oxygen rate electrode and an universal

polarograph. The initial

and

distribution and the values o f misses ( a ) and double

hits ( / i ) were calculated by the method of Kok et al (1970).

Treatment оI’barley seedlings with 100 mM NaCl for 7 days caused a significant

decline in plant growth but the plants remained turgid and healthy. Hill reaction activity

of isolated thylakoids was lowered by approximately 25% after 100 mM NaCl (Table

•О-

Table I: Action of NaCl on Hill reaction activity of isolated thylakoids,

chlorophyll a/b ratio and chlorophyll fluorescence ratio Fv/Fmax

Treatment^

Activity (%)

Chi a/b

Fv/Fmax

Control

100

2,68 ±0,18

0,47 ±0,04

100 mM N ad

74,5 + 6,1

2,58 ± 0,11

0,32±0,05

20-100 mM NaCl

88,3±7,1

2,64 ±0,15

0,40±0,06

plant growth was slightly affected, and the electron transport activity of isolated

thylakoids should an insignificant inhibition.'These results are supported by the

investigations of the chlorophyll fluorescence induction in isolated thylakoids. After a

long-term 100 itiM NaCl treatment a decrease in the Fv/Fm» ratio was obtained (Fv-

variable fluorescence and

- maximum level o f fluorescence), whereas in stepwise-

treated plants this ratio was between the values of control and NaCl stressed plants.

100 mM NaCl treatment inhibits O

flash yields without significant change in miss

parameters. .The number of operative oxygen evolving centers (So+SO was 43 % less

than in the control beet the resting centers functioned nearly as in the control (Table 2).

.Table 2: The

state populations and the value of misses and double hits

. ... according to the model of Kok et al

Treat aunts

So+S, (%)

Misses (л )

Double hits

(/3

)

Control

100

0,20 ±0,01

0,0610,01

100 mM NaCl

56,6±2,2

0,20 ±0,01

0,09±0,00

20-100 mM NaCl

94,5 ±4,6

0,19±0,01

0,08+0,00

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