Isolation and identification of Rhizobium bacteria from Faba bean (Vicia faba L.) roots grown in gypsiferous soil and testing their efficiency in production growth regulate(IAA) and siderophorses

Abstract

In this study 30 samples were collected from the root nodules of Faba bean plants (Vicia faba L.) grown in gypsiferous soil in the College of Agriculture / Tikrit University / Salah al-Din Governorate in 5/12/2020, and the isolation process was carried out on selective mediumYeast Extract Mannitol Agar , and the phenotypically pure isolates were identified based on the culture, microscopic and biochemical characteristics, and the phenotypic identification results showed that 23 isolate gave the characteristics of Rhizobium sp. ,it was color of the colonies between white, cream and yellow, shiny, convex and smooth, gram-negative and most of able to move and has color between light pink and white on Congo red stain medium (0.025%) and it most of fast growing giving them yellow color on bromothymol blue medium and unable to grow on Hofer alkaline medium, and the efficient isolate was selected in the production of indole acetic acid, chelating compounds, and identificated molecularly by PCR, the 16SrRNA gene was amplified, then the sequence of nitrogenous bases, the results showed that there is a 99.69% similarity with the Rhizobium leguminosarum bv. Viciae strain SMV12a, and therefore the isolate is genetically close to Rhizobium bacteria.