UTILIZE OF INNOVATORY PGPR STRAINS AS A BIOCONTROL FORMULARIZATION AGAINST POTATO WILT DISEASE

Potato (Solanum tuberosum L.) is the one of the most vital harvest of food on the world after rice (Oryza sativa L.) and wheat (Triticum aestivum L.). The present research was concerned about, isolation and identification of Ralstonia solanacearum from exceptional potato tubers, water, and weeds samples. The plant growth-promoting rhizobacteria (PGPR) are the really helpful microorganism that colonizes rhizosphere and help in promoting plant growth, protecting from biotic and abiotic stresses, as well as drastically growing soil fertility. For the effective ways of creating sustainable agriculture for enhancing crop productiveness with a minimal disturbance to the surroundings is the exploration of plant growth-promoting rhizobacteria and some different microbe-based symbioses in plants. For increasing crop yields, the use of PGPR has been well proven for its eco-friendly by using promoting plant growth either direct or oblique mechanism. The mechanisms of plant growth-promoting rhizobacteria include resistance against plant pathogens, solubilizing nutrients for easy uptake, and keeping the plant boom regulator hormone. The isolates pathogenic bacteria collected from three Egyptian governments (Menofia, Gharbia and Beheria) were identified by morphological characteristics, PCR and Real-time technique and classified as a Ralstonia solanacearum race 3 biovar2. The antagonistic activity of (PGPR) strains used (Bacillus circulans, Paenibacillus polymyxa, Bacillus megatherium, Pseudomonas fluorescence, Azotobacter spp, and Asospirillum spp) against the bacterial pathogen (Ralstonia solanacearum) showed that all the tested exhibited antibacterial effect against Ralstonia solanacearum. Positive response was recorded on the NPK content of plant Shoot and Root as a result for inoculation with the biocontrol agents of PGPR strains. Also, use of PGPR strains led to decrease of pathogenic bacteria Ralstonia solanacearum of potato brown rot colonies. In addition the tested PGPR against R. solanacearum using non-sterilized soil were evaluated for their abilities on reducing potato brown rot or wilt infection caused by R. solanacearum on two potato cultivars (CVs. Bellini and Hermes) under greenhouse conditions showed that the individual treating with the biotic treatments before cultivation in non-sterilized inoculated soil with R. solanacearum prevented the appearance of wilt infection for 60 days of cultivation.