METHOD OF SELECTION OF STRAINS OF RHIZOBIUM TRIFOLII ABLE TO EFFECTIVE SYMBIOSIS IN ACID SOIL WITH ENHANCED CONTENT OF ALUMINIUM ION Russian patent published in 2003 - IPC

FIELD: agriculture microbiology. SUBSTANCE: invention relates to method of selection of strains of Rhizobium trifolii able to effective symbiosis in acid soils with enhanced aluminum ions in cultivation of cow clover. Method involves two stages. At the first stage method involves selection of acid- -resistant strains of bacterium Rhizobium trifolii which are cultured for 3 days on selective leguminous nutrient medium containing Al³⁺ ions added after sterilization of medium as AlCl₃ taken in the amount 75 mg/l (up to control of pH value of medium to 4.5). Then the most effective acid-resistant strains are evaluated and selected. At the second stage method involves culturing selected strains on nitrogen-free Krasilnikov- Korenjako's medium comprising ions Al³⁺ added as AlCl₃ taken in the amount 50 mg/l (up to control of pH value of medium 4.5), by clover seedlings sowing with simultaneous inoculation of the latter with these strains. Then, clover plants are cultured under condition of artificial climate with recommended regime and in 30-35 days after sowing (in early stages of ontogenesis) strains that are able to effective symbiosis in acid soils by biomass accumulation are selected. Method allows to reduce time and simplify schedule of selection of acid-resistant strains of rhizobium bacteria, expand possibility of cow clover cultivation on acid soils being without additional consumptions for their liming and addition of nitrogen fertilizers. EFFECT: improved method of selection. 2 tbl