Plant growth-promoting microbes (PGPMs) play a crucial role in sustainable agriculture. This study aims to isolate and characterize rhizospheric actinomycetes for their potential in promoting tomato plant growth. Five isolates were obtained and screened for their morphological and biochemical characteristics, exhibiting significant variations. These isolates were identified using polyphasic taxonomy and assessed for various plant growth-promoting activities. Phosphate solubilization and siderophore production were observed in the ranges of 11-24 mm and 9-10 mm in diameter, respectively. All isolates produced ammonia, though none showed HCN production. These promising actinomycetes were tested for their plant growth-promoting (PGPR) activity on tomato seedlings in vivo. The MKT5 isolate exhibited the highest plant growth-promoting traits, surpassing all other isolates in enhancing various plant parameters compared to the uninoculated control. Given its remarkable performance in pot trials with tomato seedlings, MKT5 can be considered a potential biofertilizer for various crops. Tomato seeds treated with the MKT5 isolate demonstrated a significant increase in plant growth compared to the control and can be explored for plant growth promoting attributes. These most promising actinomycetes were examined for their plant growth promoting (PGPR) activity on tomato seedlings in in vivo.
