Naslov
Phylogenetic Analysis of Indigenous Rhizobial Strains Nodulating Soybean (Glycine max L.) and Their Symbiotic Efficiency Under Drought Conditions

Autori
Kajić, Sanja ; Aserse, Aregu ; Lindström, Kristina ; Rajnović, Ivana ; Borovec, Petra ; Pejić, Ivan ; Sikora, Sanja

Kolaboracija
Ecosystems and Environment Research programme, Faculty of Biological and Environmental, Helsinki, Finland, Sciences and Helsinki Institute of Sustainability Science (HELSUS), Finland

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

Izvornik
Book of abstracts / - : Hrvatsko mikrobiološko društvo, 2023, 48-49

Skup
Power of Microbes in Industry and Environment

Mjesto i datum
Poreč, Hrvatska, 15.05.2023. - 18.05.2023

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Podatak o recenziji nije dostupan

Ključne riječi
symbiotic associations, rhizobia, drought, 16S rRNA gene, RAPD method, nodC gene, nifH gene

Sažetak
Symbiotic associations between legumes and specific group of soil bacteria enable considerable entries of biologically fixed nitrogen into the soil. The rhizobia inoculation of soybean is a sustainable practice to induce atmospheric nitrogen fixation and subsequently improve crop productivity and soil fertility. The main advantage of indigenous rhizobial strains relates to their high competitiveness and adaptation ability to specific environmental conditions. Drought is one of the most important factors limiting nitrogen fixation, growth and yield of soybean. In this study, 60 indigenous rhizobia isolated from 29 different regions of Croatia were subjected to in vitro investigations of different water conditions. Based on the results obtained by the RAPD method, sequencing of the 16S rRNA gene and in vitro drought test representative strains were selected for further analysis of sequences rpoB, glnII, gyrB, nodC and nifH gene. Phenotypic characterization of isolates included testing the tolerance to unfavorable soil conditions intrinsic antibiotic resistance, biochemical characterization, assimilation of different carbon sources, generational time and screening for plant growth promoting properties (PGPR). Greenhouse experiment was setup using two factors on the basis of a completely randomized block design. The 16S rRNA results showed that 75% strains from this study belong to genus Bradyrhizobium. Phylogenetic analysis of the three housekeeping genes rpoB, gyrB and glnII showed that the strains were identified as B. diazoefficiens and B. ottawaense species for the first time in Croatian soils and species B. japonicum identified earlier. The results of the nodC gene analysis of indigenous rhizobial strains isolated from Croatian soils showed that all of them belong to the symbiovar glycinearum. The phylogeny of most nifH genes coincides with the phylogeny of the nodC gene indicating the co- evolution of these two genes. PGPR characterization of isolates showed their significant variability. Results of greenhouse experiment showed that the hightest nodule number was obtained when soybean was inoculated with indigenous strain S1/5 (B. japonicum). Nodule dry weight is parameter indicating nodulation capacity of strain. Strains S3/5 (B. japonicum) S25/2 (B. diazoefficiens) S32 (B. ottawaense) and S37 (B. japonicum) showed significant tolerance to unfavourable conditions and PGPR characterization.

Izvorni jezik
Engleski

Znanstvena područja
Poljoprivreda (agronomija)

POVEZANOST RADA