Naslov
Biodiversity of indigenous alfalfa rhizobia isolated from soils in central Croatia

Autori
Sikora, Sanja ; Kajić, Sanja ; Dežić, Sandra ; Blažinkov, Mihaela

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, ostalo

Skup
VI International Conference on Environmental, Industrial and Applied Microbiology-BioMicroWorld 2015

Mjesto i datum
Barcelona, Španjolska, 28.10.2015. - 30.10.2015

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
nitrogen fixation; Sinorhizobium meliloti; indigenous strains; phenotypic characterization; 16S rDNA PCR-RFLP; RAPD; ERIC-PCR

Sažetak
In agricultural production, nitrogen is one of the most common limiting factors for growth and development of plants and also for achieving optimum yield. The largest stock of nitrogen is in the atmosphere, where it is in a molecular form which plants are not able to uptake or use. The process of nitrogen fixation is defined as process in which unavailable nitrogen from the atmosphere is transformed into new compounds, and thereby becomes available to microorganisms and plants to use it for their own metabolic needs. Symbiotic nitrogen fixation has a unique role in agriculture because the utilization of this natural process enables significant reduction of mineral nitrogen fertilization. Selection of highly efficient symbiotic nitrogen fixators is of great importance for successful legume inoculation due to the fact that the strains of nodule bacteria strongly differ in their symbiotic efficiency, competitiveness and compatibility. The aim of this study was the isolation of indigenous alfalfa rhizobia from the region of central Croatia, determination of their phenotypic characteristics and evaluation of genetic variability within natural populations of these soil bacteria. The study also included reference strain of Sinorhizobium meliloti 2011 and type strain Sinorhizobium medicae 18864T. Two biochemical tests, lactose agar test and mobility of phosphate were used. For the purpose of phenotypic characterization, indigenous strains were tested for the growth at elevated temperatures, the pH values different from the optimal ones, and at elevated concentrations of NaCl. The identification of strains was performed by using three molecular methods based on PCR amplification: 16S rDNA PCR - RFLP, RAPD and ERIC - PCR. Lactose - agar test showed that six isolates belonging to genus Agrobacterium. The results of phenotypic characterization showed that the strains differ in their ability to grow at high temperatures, at different pH values, at different concentrations of NaCl and in phosphate mobility. The results of 16S rDNA PCR – RFLP method showed that nine strains could be regarded as S. meliloti while RAPD and ERIC - PCR revealed the presence of significant genetic diversity between the indigenous alfalfa rhizobia.

Izvorni jezik
Engleski

Znanstvena područja
Poljoprivreda (agronomija)

POVEZANOST RADA