| In order to study effects of TR21 wettable powder on soil microorganism in banana rhizosphere, ten rhizosphere soil samples from different planting stage treated by TR21 wettable powder and water control were collected, and the total DNA of each soil was extracted respectively, and also, the differences in microbial composition of rhizosphere soil were compared with the methods of PCR-DGGE, main strip recovery, gene cloning and sequencing analysis. The results showed that: Compared with the soil samples without banana planting, both S value (species richness) and H value (diversity index) in the control treatment rhizosphere soil decreased in the early stage of banana planting, but the S value increased and the H value changed little in rhizosphere soil of TR21 treatment.In the middle stage of banana planting, the S value and H value of the control treatment rose to the level of the non planting value, but TR21 treatment's S value increased and its H value decreased. During the later stage, in the rhizosphere soil both treatment of the control and TR21 S value increased and H value decreased continuously. However, the S values of TR21 treatment were greater and the H values were less than that of the control treatment. The number of Bacillus in rhizosphere soil increased after TR21 treatment according to the identification of differential bands and the analysis of main bands recovery and sequencing. Thus, the S value and the number of bacilli in rhizosphere were increased with application of Bacillus subtilis TR21 wettable powder by irrigating the root of bananas. |
