الفهرس 
Chapter 1. IntroductionOnly 14 pages are availabe for public view
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Abstract
Plant-associated bacteria that live inside plant tissues without causing any harm to plants are defined as endophytic bacteria and encourage plant growth by a wide variety of mechanisms. 25 bacterial isolates were obtained from root of wheat and maize and examined in vitro for achieving the traits that being related to plant growth promoting effects and optimal conditions for that at different cultural conditions as well as, three pot experiments were carried out to study the impacts of rhizobacterial inoculation on growth of wheat and maize plants. The findings of the study showed that 8 isolates were phosphate solubilizing bacteria, 10 isolates produced indole acetic acid (IAA) and 2 isolates were N2-fixing bacteria. Also, 5 isolates produced cellulase and pectinase enzymes, while 2 isolates produced pectinase only. The maximum IAA production and phosphate solubilization was observed at pH 7.0 after 5 and 6-12 days of incubation period, respectively. The increase in Ltryptophan concentration 1 to 4 mg/ mL, resulted a linear increase in IAA production. Plant parameters (shoot length, root length, shoot fresh and dry weight, root fresh and dry weight, chlorophyll a, chlorophyll b and carotenoids content, number of leaves) and mineral contents (NPK) of wheat and maize were significantly increased by inoculation with used isolates. On a comparative basis isolates 9WH and 6PC were most promising in promoting plant growth. The results indicated the possibility of producing biofertilizer for enhancing wheat and maize growth by using beneficial strains of PGPR.