To study the effect of plant growth-promoting rhizobacteria on tomato bacterial wilt and growth, two PGPR combinations T1 and T2 were prepared based on the resistance relationship of Bacillus mucilaginosus BX-1, Bacillus su

Abstract

To  study  the  effect  of  plant  growth-promoting  rhizobacteria  on  tomato  bacterial  wilt  and  growth,  two  PGPR  combinations  T1  and  T2  were  prepared  based  on  the  resistance  relationship  of  Bacillus  mucilaginosus  BX-1,  Bacillus  subtilis  BX-2,  Bacillus  pumilus  BX-4  and  Pseudomonas  fluorescences  X-5.  Pot  experimental  results  indicated that application of the two combinations could reduce the disease incidence of tomato bacterial wilt, and  the bio-control efficacy  reached 54.5% and 45.5%  respectively on  the 40th day after  transplanting. The biomass  showed  that height  and  fresh weight  increased  obviously  after  inoculation,  especially  for  the T2  treatment,  and  compared to the control, the height, fresh weight, dry weight and fruit number improved 16.38%, 30.91%, 17.85%  and 29.17%. Meanwhile, inoculating PGPR combinations could affect soil microbial diversity to some degree, and  the soil microbial diversity indexes, i.e. AWCD and Shannon, were greater than control for the samples of 25th and  40th  day.  In  addition,  PGPR  combinations  could  also  induce  tomato  systemic  resistance  and  improve  the  defense-related enzyme activities. The enzyme activities were all higher than control after inoculation for 24h.  

Keywords:  plant  growth-promoting  rhizobacteria;  tomato  bacterial  wilt;  bio-control  efficacy;  defense-related enzymes; soil microbial diversity