Endophytic actinobacteria as biocontrol agents and enhancers of N-fixation for lucerne (Medicago sativa L.).

Selected endophytic actinobacteria have been shown to enhance the yields of crop plants via a number of mechanisms. In addition to cereal crops, endophytic actinobacterial strains were found to enhance the symbiosis between legumes and rhizobia resulting in a significant increase in biological Nitrogen fixation. Coombs et al. (2004) reported that actinobacteria isolated from healthy cereal plants including a number of Streptomyces, as well as Microbispora and Nocardioides spp. were able to control the development of disease symptoms in treated plants exposed to Ggt and Rhizoctonia in the field soil. This study aims to identify potential biocontrol activity of endophytic actinobacteria that were also able to enhance symbiotic nitrogen fixation.