Naslov
Genetic identification and symbiotic efficiency of an indigenous Sinorhizobium meliloti field population

Autori
Bradić, Mihaela ; Sikora, Sanja ; Redžepović, Sulejman

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

Izvornik
Croatian, Hungarian and Slovenian Symposium on Industrial Microbiology and Microbial Ecology, Book of Abstracts / Mrša, Vladimir ; Hajsig, Danko - Zagreb : Prehrambeno-biotehnološki fakultet Sveučilišta u Zagrebu, 2002

Skup
Power of Microbes in Industry and Environment

Mjesto i datum
Opatija, Hrvatska, 07.06.2002. - 09.06.2002

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
Sinorhizobium meliloti; alfalfa; isolation of indigenous strains; identification; symbiotic efficiency

Sažetak
Soil bacteria Sinorhizobium meliloti are of enormous agriculture value, because of their ability to fix atmospheric nitrogen in symbiosis with important forage crop legume - alfalfa. Symbiotic relationship of alfalfa and efficient S. meliloti strains can significantly reduce the application of mineral nitrogen fertilizer which has important economical and ecological effects. Therefore, the selection of efficient strains is very important for inoculant production. It is also important to characterize the natural population of S. meliloti because the presence of adapted and competitive indigenous soil strains can reduce the inoculation effect. The main aim of this study was (i) to isolate indigenous S. meliloti strains from different field sites in Croatia, (ii) to assess genetic diversity and genetic relationship amongst strains of natural population and (iii) to provide information about nodulation and symbiotic efficiency of indigenous S. meliloti strains. The nine strains isolated from alfalfa nodules collected from different field sites and three reference strains were analysed. All isolates were identified and compared with selected reference strains by using PCR-RFLP of the 16S rDNA method which is especially applicable for determination of inter- and intra-generic relationship between rhizobial species. This method revealed that all isolates belong to the S. meliloti species. For distinction of isolates at the strain level, two highly discriminative molecular methods - RAPD and rep-PCR were used. Strain - specific fingerprint patterns were produced by both methods. Cluster analysis of PCR profiles revealed a significant differences between isolated S. meliloti strains. Both methods resulted in identical grouping of strains. Among indigenous strains two divergent groups can be determined. The highest differences were also detected among two reference strains and all field isolates. Greenhouse studies were also performed for evaluation of symbiotic efficiency and compatibility of S. meliloti strains with two alfalfa cultivars. Quantitative expression of symbiotic efficiency was evaluated by measurement of root nodules dry weight, content of proteins in plants, content of total nitrogen in plants, dry matter and green mass yield of plants. All strains nodulated both alfalfa cultivars but with different efficiency. Significant differences in dry matter and green mass yield of alfalfa as well as protein content in plant were determined depending on the strain used. The results indicate that three indigenous S. meliloti strains can be characterized as the most efficient of all tested strains

Izvorni jezik
Engleski

Znanstvena područja
Poljoprivreda (agronomija)

POVEZANOST RADA