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forms. In both cases doses of lead were 0, 10, 30, 50, 400, 1000 mg/kg

soil. The sowing of

Dactylis glomerata L

was made in containers two

weeks later. Soil solution was collected using Rhizon® samplers for

soil moisture collection (Rhizon® Flex Special Samplers, Rhizosphere

Research Products, Wageningen, the Netherlands). Soil solution and

plants for analysis were collected in May 2002 and June 2004. For lead

content determination plant leaves were dry out at room temperature,

and destroyed in microwave by digestion in concentrated HN03. Lead

concentration in plant extracts and soil solutions was determined by

ICP-MS using spectrometer “HP 4500 plus”, (RIVM, the Netherlands)

and by GF AAS using spectrometer Spectra AA 250 plus, Varian

(“TEST”, Pushchino).

Chlorophyll fluorescence was measured in fully developed flag

leaves using single-beam mode lab-built set-up (Kreslavski et al.,

2001). Fluorescence was excited with blue radiation (X^ = 480 nm);

light intensity at the leaf surface was 30Wm'2. Chi fluorescence was

detected using 685 nm interference filter (10 nm bandpass) and

monochromator (AX = ±1 nm) with photomultiplier, the signal was

recorded by oscilloscope (Tektronic) or recoreder Endim 322-01M

(VEB MS, Germany). Parameters calculated from fluorescence curve

were Fv - variable fluorescence, F0- permanent fluorescence, and the

ratio Fv/ F0 reflecting the activity of Photosystem II (Krause and Weis,

1991).

Results. At the same high levels of contamination lead content in

soil solution and leaves were higher in the case of metal addition in

soluble form then in the form of the Pb02. Despite of high variability of

measured values, Pb concentrations in leaves could be statistically

significantly described as a function of Pb concentration in soil solution

regardless of the form of metal addition (Fig. 1).

No significant effect of Pb on the activity of photosynthetic apparatus

was observed in the beginning of the first vegetation period (May 2002,

Fig. 2a). At the same time, considerable difference between control and

contaminated variants was recorded in Pb concentration in leaves, soil

solution, and the amount and state of plants (Golovnina and Pampura,

2003). In the case of Pb dose 1000 mg/kg in the form of nitrate only

one plant came up and the amount of plant material was not enough for

measurements.

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