Growth Promoting Capacity in Barley (Hordeum vulgare) and Antagonistic Potential of Rhizobium leguminosarum and Rhizobium Etli

Abstract

Sustainable agriculture intends to improve nitrogen fixation efficiency through the use of competitive plants (legumes) and bacteria (rhizobia), capable of being used in biofertilization, bioremediation and phytoremediation, thereby extending the advantages of symbiosis to other crops. In that sense, research has been focused on the study of rhizobia able to promote the growth of legumes and non legumes through different mechanisms, a process known as PGP (Plant Growth Promoting) capacity. The goal of this work was to evaluate the ability of 19 Rhizobium leguminosarun and Rhizobium etli strains to promote the growth of barley plants (Hordeum vulgare) and to antagonize Alternaria solani and Fusarium sp growth. The capacity to promote plant growth was evaluated in green house conditions while antagonistic activity assays were performed in vitro. Eighty nine percent of the Rhizobium strains tested stimulated the growth of barley plants, increasing the total dry matter between 8 to 37%. Sixty three percent of the rhizobial strains showed antagonistic capacity towards A. solani and 84% towards Fusarium sp. being the growth inhibition of 49% and 43% respectively. In this work we demonstrate that some R. leguminosarum and R. etli strains can promote the growth of barley plants and control the phytopathogenic fungi Fusarium sp. and A. solani in vitro conditions.