The influence of microbial associations on germination of wheat seeds and growth of seedlings under impact of zinc salts Original Research Article

The life support systems (LSS) for long-term missions are to use cycling-recycling systems, including biological recycling. Higher plants are the traditional regenerator of air and producer of food. They should be used in many successive generations of their reproduction in LSS. Studies of influence of microbial associations on germination of wheat seeds and on growth of seedlings under impact of heavy metals are necessary because of migration of heavy metals in LSS. Microbial associations are able to stimulate growth of plants, to protect them from pathogenic organisms and from toxicity of heavy metal salts. The goal of this work was to investigate effect of microbial associations on the germination of wheat seeds and on the growth of seedlings under impact of different concentrations of ZnSO4. The results of investigations showed that: (1) Zinc salt had an adverse effect on germination of wheat seeds, beginning with concentrations of 8 MPC (Maximum Permissible Concentration) and higher. (2) Microbial associations (concentrations −104 to 107 cells/ml) were able to decrease (partly or completely) the adverse effect of ZnSO4 on germination of wheat seeds. (3) Concentrations (104–107 cells/ml) of microbial associations were able to decrease partly the adverse effect of zinc salts (intervals: from 1 to 32 MPС) on the growth and development of wheat plantlets during heterotrophic phase. (4) The root system of plants was more sensitive to the adverse effect of ZnSO4 than shoots of plants.