Genetska raznolikost i simbiozna učinkovitost autohtonih rizobija koje noduliraju grah u Hrvatskoj

Autor: Ines Pohajda, Katarina Huić Babić, Ivana Rajnović, Sanja Kajić, Sanja Sikora
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Zdroj: Food Technology and Biotechnology
Volume 54
Issue 4
ISSN: 1334-2606
1330-9862
Popis: Nodule bacteria (rhizobia) in symbiotic associations with legumes enable considerable entries of biologically fixed nitrogen into soil. Efforts are therefore made to intensify the natural process of symbiotic nitrogen fixation by legume inoculation. Studies of field populationsof rhizobia open up the possibility to preserve and probably exploit some indigenous strains with hidden symbiotic or ecological potentials. The main aim of the present study is to determine genetic diversity of common bean rhizobia isolated from different field sites in central Croatia and to evaluate their symbiotic efficiency and compatibility with host plants. The isolation procedure revealed that most soil samples contained no indigenous common bean rhizobia. The results indicate that the cropping history had a significant impact on the presence of indigenous strains. Although all isolates were found to belong to species Rhizobium leguminosarum, significant genetic diversity at the strain level was determined. Application of both random amplifi cation of polymorphic DNA (RAPD) and enterobacterial repetitive intergenic consensus–polymerase chain reaction (ERIC-PCR) methods resulted in similar grouping of strains. Symbiotic efficiency of indigenous rhizobia as well as their compatibility with two commonly grown bean varieties were tested in field experiments. Application of indigenous rhizobial strains as inoculants resulted in significantly different values of nodulation, seed yield as well as plant nitrogen and seed protein contents. The most abundant nodulation and the highest plant nitrogen and protein contents were determined in plants inoculated with R. leguminosarum strains S17/2 and S21/6. Although, in general, the inoculation had a positive impact on seed yield, differences depending on the applied strain were not determined. The overall results show the high degree of symbiotic efficiency of the specific indigenous strain S21/6. These results indicate different symbiotic potential of indigenous strains and confirmed the importance of rhizobial strain selection. These are the first studies of indigenous common bean rhizobia in Croatia that provide the basis for further characterization and selection of highly efficient indigenous strains and their potential use in agricultural practice and future research.
Kvržične bakterije (rizobije) u simbioznim zajednicama s leguminozama omogućuju značajan unos biološki vezanog dušika u tlo. Stoga se prirodni proces simbiozne fiksacije dušika nastoji što više potaknuti inokulacijom leguminoza. Proučavanjem prirodnih populacija rizobija otvara se mogućnost očuvanja i eventualnog korištenja nekih autohonih sojeva sa skrivenim simbioznim ili ekološkim potencijalom. Glavna je svrha ovog istraživanja bila utvrditi genetsku raznolikost rizobija koje noduliraju grah, izoliranih iz tala s različitih područja središnje Hrvatske, te procijeniti njihovu simbioznu učinkovitost i kompatibilnost s biljkom domaćinom. Postupak izolacije pokazao je da većina uzoraka tla ne sadržava autohtone rizobije koje noduliraju grah. Rezultati pokazuju da se sadnjom pretkultura bitno povećala prisutnost autohtonih sojeva. Premda je za sve izolate utvrđeno da pripadaju vrsti Rhizobium leguminosarum, utvrđena je značajna genetska raznolikost sojeva. Primjenom metoda RAPD i ERIC-PCR dobivene su grupe sličnih sojeva. U pokusima na polju ispitana je simbiozna učinkovitost autohtonih rizobija, i njihova kompatibilnost s dvije najčešće uzgajane sorte graha. Inokulacijom pomoću autohtonih sojeva rizobija, dobivene su bitno različite vrijednosti nodulacije, prinosa sjemena, te udjela dušika u biljci i proteina u zrnu. Najuspješnija nodulacija i najveći udjeli dušika u biljci te proteina u zrnu utvrđeni su u biljkama inokuliranim sojevima R. leguminosarum S17/2 i S21/6. Iako je inokulacija uglavnom pozitivno utjecala na prinos zrna, nije utvrđeno da on ovisi o upotrijebljenom soju. Sveukupni rezultati pokazuju veliku simbioznu učinkovitost specifičnog autohtonog soja S21/6, te različit simbiozni potencijal ostalih sojeva, što potvrđuje značaj selekcije rizobija. Ovo su prva istraživanja autohtonih sojeva rizobija koje noduliraju grah u Hrvatskoj, što čine osnovu za njihovu daljnju karakterizaciju, selekciju visokoučinkovitih sojeva te moguću primjenu u poljoprivrednoj praksi i daljnjim istraživanjima.
Databáze: OpenAIRE
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