[Production of auxins by the endophytic bacteria of winter rye].

The ability of the actinomycetes and coryneform bacteria isolated from the root tissues of winter rye to produce auxin in a liquid culture was studied. The isolates of coryneform bacteria produced indolyl-3-acetic acid (IAA) into the medium in the amount of 9.0-95.0 microg/ml and the isolates of actinomycetes in the amount of 39.5-83.0 microg/ml. The maximal IAA accumulation in culture liquid of actinomycetes coincided, in general, with the beginning of the stationary growth phase. The dependences of IAA synthesis by actinomycetes on the composition and pH of nutrient medium, tryptophan concentration, and aeration conditions were determined. Biological activity of the bacterial IAA was assessed. Treatment of winter rye seeds with coryneform auxin-producing bacteria increased the germination capacity and enhanced an intensive seedling growth in vitro.