The use of Streptomyces isolate with plant growth promoting traits in the production of English ryegrass

Abstract

© 2016, National Agricultural Research and Development Institute Fundulea. All rights reserved. The aim of this study was the isolation and characterization of actinomycetes (Streptomyces sp.) with PGP traits in the rhizosphere of perennial ryegrass, and monitoring the impact of their use on the parameters of the English ryegrass (Lolium perenne) yield and microbiological activity in its rhizosphere. The isolates had different growth characteristics. All three isolates produced a greater amount of indole-acetic acid (IAA) in the medium with added L-tryptophan. Isolate A3 produced siderophors and hydrogen cyanide, while isolates A1 and A2 utilized organic phosphorus. All isolates were produced cellulase, urease and gelatinase but not amylase. Isolates A1 and A3 produced lipase while A2 produced a protease. Isolate A3 was chosen for the examination of the isolate impact on plant yield. When evaluated on English Ryegrass in the field, during the first year of experiment, the isolate A3 affected positively the yield of fresh and dry mass, root and stem length. During the second year, the isolate A3 statistically significant enhanced the measured parameters over the control. In relation to Trichoderma asperellum, application of isolate A3 had a better effect on the plant yield. The number of investigated group of microorganisms and dehydrogenase activity in the inoculated variant increased in comparison with the control.