RAPD profiling of Bacillus spp with PGPR potential and their effects on mineral composition of tomatoes

Abstract

Bacillus species have been known to antagonize and inhibit the growth of various plant pathogens but quality of crop from such plants is yet to be investigated. The aim of this study is to analyze the mineral composition of tomato to which Bacillus isolates were applied as a biocontrol agents whose relatedness and diversity has been profiled using the Random Amplification of Polymorphic Deoxyribonucleic acid (RAPD). Eleven Bacillus isolates were characterized by using RAPD primers and four of them, that is, B. amyloliquefaciens, B. cereus, B. pumilus and B. subtilis were randomly selected as antagonists against Fusarium wilt pathogen in tomatoes. Harvested tomatoes were analyzed for mineral composition using Energy Dispersive X-ray 720. Diversity of the eleven Bacillus isolates were profiled using primers S4, A9B7 and OPH 19 and 76 bands were produced. Bands from primer A9B7, OPH 19 and S4 were 90.9, 87.5 and 92.5 percent polymorphic, respectively. Plants treated with B. cereus had highest fresh and dry mass of tomato plant as compared to control, whereas, B. amyloliquefaciens treated plants had significantly bigger tomatoes with highest quantity of potassium, copper and rubidium. Tomatoes from treatment with B. subtilis had highest quantity of calcium while those from B. pumilus had highest quantity of manganese and rubidium. These results suggested that these Bacillus isolates can be used to promote plant growth and quality of tomato while their consortium can be researched.