Diversity of endophytic bacteria in Jujube and their antimicrobial activity against pathogens

Endophyticbacteria reside within plant tissues without causing any diseases in those plants. Studies on endophytesin Jujube have focused on the isolation of diazotrophicbacteria. In all, 212 colonies were isolated from internal tissues of Jujube root, branch, and leaf. Of these, 19 isolates were selected for analysing antibiotic activity and isolate identification. Phylogenetic analysis based on 16S rDNA gene sequences showed that the isolates belonged to Bacillus, Pseudomonas, Agrobacterium, Nesterenkonia, Stenotrophomonas, Staphylococcus, Pedobacter, Arthrobacter, Rhizobium, Williamsia, Chryseobacterium, Gamma proteobacterium, and Pseudoclavibacter. The dominant genera were Bacillus (35.8%), followed by Staphylococcus (26.42%) and Arthrobacter(17.45%). Antagonistic assays showed that four isolates expressed antibiotic activity against Alternariaalternate, Allantophomoides carotae, Fusarium graminearum, Bipolaris maydis, Alternariaalternate f. sp. mali, Cytosporasp., Botrytiscinerea, and Botryosphaeria berengerianaf. sp. pyricola. The current study indicates that selected endophyticbacteria strains have the potential for biological control of plant diseases.