Action Pb2+ and CD2+ on background of NaCl salinity on indicators of water exchange of the leaves of Lollium perenne L.

Abstract

The effect of heavy metals (Рb2++Сd2+) and salinity (NaCl) on leaves water exchange parameters Lollium perenne L. is studied. The experiment was carried out in four ways: 1) control (unpolluted soil); 2) in the soil brought Рb2+ and Сd2+ 0,1 and 0,003 g/kg; 3) in the soil brought NaCl in an amount of 0,2 g/kg; 4) in the soil brought all investigated pollutants (Рb2++Сd2+ and NaCl) in the same amounts, in versions 2 and 3. It was established that plants of all variants did not significantly differ in the total water content in the leaves. The amount of bound water significantly higher in the experimental plants compared to control, especially in variants with salinity.The water-holding capacity of leaves of plants on the 30th, 38th and 45th day was analyzed. Major water losses were observed in the control, the highest water-retaining capacity in plants exposed to all investigated pollutants. Thus, for the actions in a Lollium perenne within 30 days of complex pollutants (Рb2++Сd2+ and NaCl) water-retaining capacity greater compared with the effect of only NaCl. With increasing cultivation periods (45 days) the difference in this index between these options is not found. Influence of heavy metals is much smaller.In all variants curve of intensity transpiration of leaves has a one vertex with the maximum in the midday hours. The comparison of the intensity of transpiration in leaves of plants grown in different versions shows that on 30 day maximum value of this index in control, the lowest – for the joint action of heavy metals and chloride salinity. With the decline of this index can be arranged as follows: variant of control > Рb2++Сd2+ > NaCl > Рb2+ + Сd2++NaCl. At 45 days, the highest average intensity of transpiration was found in the variant with heavy metals (Рb2+ + Сd2+) – is significantly higher than the control. The lowest intensity of transpiration was in leaves of plants grown in versions with salty.The reaction of 45-day-old plants of the transpiration parameter largest impact on salinity remains the same as in the 30-day. The response to the effect of heavy metals varies. In joint action on plants Рb2++Сd2++NaCl is lower than when exposed only Рb2+ + Сd2+, but higher than the action only salinization.