Abstract
In this study, screening of rhizobacterial community structure was performed to obtain potential rhizosphere bacterial community for plant growth promotion in dryland agriculture. Rhizosphere soil samples were collected from better growth performance of maize planted in dryland farm. Eleven rhizosphere soil samples were selected based on their effect on the growth of maize in a greenhouse. The water holding capacity of maize growth medium was adjusted in 100, 75 and 50%. Rhizobacterial communities were analyzed using Terminal Restriction Fragment Length Polymorphism (RFLP) based on metagenomic and cultivation-dependent approaches. The TR D is the best maize rhizosphere soil sample obtained from in planta screening. In the 50% water holding capacity, TR D treatment can increase the vegetative growth of maize. The TR D treatmen generally showed increased fresh weight of upper biomass (47.1%), dry weight of upper biomass (45.2%) and root dry weight (33.4%). The bacterial community structure of TR D included Burkholderiales, Pseudomonas, Bacillus, Candidatus, Alphaproteobacteria, Betaproteobacteria, Rhizobiales, Sinobacteraceae and Acidobacteria. Burkholderiales is the dominant group in metagenomic and Pseudomonas sp. is the dominant group in cultivation-dependent approach. In the other soil samples, such as TR A and TR K1, Burkholderiales and Bacillus sp. were the dominant. This study indicated that in planta screening can use to obtain potential rhizosphere bacterial community for growth promoting of maize in dryland.