Development of the PGPR and Cyanobacteria Consortium for Growth Promotion and Control Ralstonia syzigii subsp. indonesiensis of Tomato

Abstract

Plant growth-promoting rhizobacteria (PGPR) are known in various cropping systems to increase plant growth, vigour and plant nutrient contents. cyanobacteria are known to possess the ability to form associations with vascular/non-vascular plants and produce growth-promoting substances. The present work was undertaken to formulate the best effective consortium consist of plant-growth-promoting rhizobacterium and cyanobacteria to promote growth rate of tomato and control R. syzigii subsp. indonesiensis. Our previous study had screened 7 best rhizobacteria (Bacillus thuringiensis strain RBI 2AB1.1, Bacillus cereus strain HYM 88 RBI 2AB 2.1, Bacillus cereus strain APSB-03 RBI 2AB 2.2, Bacterium JP60 RBI 2 AB 2.3, Bacillus sp. M6 RBI KDA 1.2, Bacillus cereus strain JN23 RBI KDA 2.2 and Bacillus subtilis BSn5 RBI IPBL 2.3) and 4 cyanobacteria strain (RZ2AB2.1, RZ1AB2.3, RZ1BPL2.3, RZSD1.1) to promote growth of tomato. To increase those strains’ ability both for suppress pathogen attack and promote growth, development of suitable consortium is necessary. Our research consists of two phase which were in vitro dual culture studies for interaction assay, and in planta consortium assay. Results shown that almost all strains were had a good compatibility to growth together. We develop 12 consortiums based on its previous ability and the compatibility. All consortiums shown capability to reduce bacterial wilt disease development and also promote growth of tomato. Consortium consist of Bacillus thuringiensis strain RBI 2AB1.1, Bacillus cereus strain APSB-03 RBI 2AB 2.2, Bacillus subtilis BSn5 RBI IPBL 2.3 and cyanobacteria RZ2AB2.1) shown best ability to reduce disease development and promote growth and yields of tomato.