Plant growth promoting rhizobacteria (PGPR) play an important role for improving plant growth and increasing productivity especially under stress condition. Fifty rhizobacterial isolates were isolated from the rhizosphere of the wheat plants. The rhizobacterial isolates were screened to select the most salt tolerant isolates. Then, the more tolerant isolates were evaluated for plant growth promoting activities such as ammonia, HCN, siderophores, nitrogenase, indole acetic acid (IAA) and gibberellins (GB) production as well as, root colonization ability, phosphate and potassium solubilization. The obtained data showed that, rhizobacterial isolate number (40) exhibited high records for most of PGPR activitiesand identified asPaenibacillus polymyxaMG309677.1using 16S rRNA gene sequencing techniques with 99% similarity. One of the problems which face production of microbial preparations for agriculture use is the maintenance of bacterial viability. In this respect, immobilization of P. Polymyxa MG309677.1 on three different carriers (peatmoss, compost and sawdust) was studied. Peatmoss and compost were used singly or combined with sawdust at two levels (50% and 75% sawdust).Bacterial populations, dehydrogenase activity, pH values and moisture contents were determined monthly up to six months of storage. Resultsrevealed that, using of peat moss either singly or combined with sawdust (50:50%) as a carrier gave the highest survival and population records forP. polymyxaMG309677.1even the end of storage period (180) days. |
