Abstract

Endophytic actinobacterias represents a potential source of microorganisms capable for synthesizing secondary metabolites of pharmacological interest and antibacterial activity, due to they has been proposed as potential biological control agents. The use of endophytes represents a new strategy for controlling phytopathogens on crops of agricultural importance. The study of the microbial communities associated with the Chilean native potato, represents a unique and unexplored search for potential biocontrol agents The particular interest is the study of actinobacterias associated to the root system and Chilean native potato tuber for finding new agents that could have competent capacity to establish symbiotic relationships and enhance plant growth commercial potato crop. The aim of this study was to determine Species richness in the community of endophytic and Rhizospheric actinobacterias from Chilean native potato (Solanum tuberosum). Plant material was collected from native Chilean native potato (Solanum tuberosum) cultured on Chiloe Region, (south of Chile) which corresponding to a crop origin center. To study the endophytic community a physical disinfection using sonicator was performed, followed of a chemical disinfection using chlorine 3%, ethanol 70% and PBS tween 20 0.01%. For studying rhizosphere was carefully retirement community soil particles attached to the root with distilled water. For studying of actinobacteria specific richness the V3 region of the 16S ribosomal DNA gene was analyzed by PCR-DGGE. Bioinformatics cluster analysis of DGGE bands was analyzed using the Multivariate Statistical Package software and 16 S rDNA sequences with the Basic Local Alignment Search Tool and the significance of the microbial richness changes was evaluated by ANOVA. The polymorphisms pattern of rhizospheric and endophytic actinobacterias communities founded on Chilean native potato throw a poor significance wealth (P <0.05) compartments endophytes of roots and tubers. Similarity analysis of the structures of the three replicas of the communities differed within a range of 30% to 40%.There was consistency in the distribution of the different studied tissues, ie, tuber and root system replicas. These differences are explained in terms of richness rather than the identity of the constituent groups. The identity of the dominant members of these communities was related to Streptomyces sp. and Micromonospora sp. The richness of the endophytes community was significantly poor (P <0.05) relative to the total richness of the rhizospheric community. These results could explain the optional capabilities of some members of the rhizosphere community to settle in endophyte infected and compartments. The identities of the dominant groups were related to Streptomyces sp. and Micromonospora sp. This is the first report of the distribution of wealth of actinobacterias in native potatoes.