Effect of Capsicum annuum cultivated in sub-alkaline soil on bacterial community and activities of cultivable plant growth promoting bacteria under field conditions

ABSTRACTIn literature, it remains little explored the soil–plant relationships within Capsicum agroecosystem. We studied how chili peppers plants contribute to influence microbial diversity. Across the bulk and rhizosphere soils of three genotypes of Capsicum annuum, the structure, the diversity and the abundance of bacteria was evaluated by means of DNA-based culture-independent approach. Furthermore, 515 bacterial strains isolated from the bulk and rhizosphere soil, were used to investigate the effect of C. annuum on four plant growth promoting bacteria (PGPB) abilities. Our results indicated that the three genotypes influence differently the physical-chemical and microbial properties of soil around the roots. Bacterial abundance resulted in increasing with different trend rhizospheres to bulk soil ratio; however, bacterial diversity was significantly higher only in the rhizosphere of one genotype. Only the indolic compounds production was stimulated in the rhizosphere of the three cultivars. Inhibition...