Original scientific paper

PHENOTYPIC CHARACTERIZATION OF INDIGENOUS SINORHIZOBIUM MELILOTI STRAINS

Mihaela Blažinkov ; Agronomski fakultet Sveučilišta u Zagrebu, Zagreb, Hrvatska
Darija Vrbanac ; Agronomski fakultet Sveučilišta u Zagrebu, Zagreb, Hrvatska
Katarina Huić Babić ; Agronomski fakultet Sveučilišta u Zagrebu, Zagreb, Hrvatska
Sanja Sikora ; Agronomski fakultet Sveučilišta u Zagrebu, Zagreb, Hrvatska

Abstract

Symbiotic relationship between nitrogen fixing bacteria Sinorhizobium meliloti and alfalfa (Medicago sativa L.) provides a significant input of biologically fixed nitrogen in soil. Alfalfa inoculation by highly efficient S.meliloti strains to enhance naturally occurring biological nitrogen fixation has been a common agricultural practice. The most importanat key for success of pre sowing alfalfa inoculation is selection the most efficient strain that is also compatibile to different ecological conditions. The main aim of his study is to determine the biochemical and ecological characteristics of indigenous S.meliloti strains in order to reveale strains diversity according growth characteristics under different temperature conditions, pH values, salt concentration, carbon source assimilation and antibiotic resistance. The results of this study reveale considerable phenotypic diversity of all tested S.meliloti strains. Beside mannitol, all strains could grow on cellobiose, mannose, galactose, melobiose, but they were not able to utilize xylose, arabinose and raffinose as carbon source. Under strong acidic conditions (pH 3) none of the strain could grow, but at pH 5 media indigenous strains Z21 and V11 and reference strain 2011 grew well. None of tested isolates could grow on concentration of 2% NaCl, but strains V11, Os6, Os5 and Z21 could grow in medium containing 0,5% and 1% of NaCl. This study revealed that strains varied in their ability to grow at higher temperatures. The strains V11, C16 and Os4 were able to grow at a temperature 40°C, but strains Os6 and Z21 failed to grow at 37°C and 40°C.

Keywords

Simbiotic nitrogen fixation; Sinorhizobium meliloti strains; Alfalfa; Phenotypic characterization

Hrčak ID:

68091

URI

https://hrcak.srce.hr/68091

Publication date:

25.2.2011.

Article data in other languages: croatian

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