Isolation and Molecular Diagnosis of Enterobacter cloacae and Kineococcus radiotolerans from Red Clover nodules and evaluation of the prepared inoculum from them as a stimulator for plant growth

Abstract

To obtain biological inoculum that promotes plant growth and contributes to a clean environment and sustainable agriculture, twentyone samples were collected from the root nodes of the red clover plant (Trifolium paratens) grown in gypsiferous soils at the Research Station of the Department of Soil Sciences and Water Resources-Faculty of Agriculture-University of Tikrit, samples were cultured in the medium of YEMA. Two isolates belonging to Enterobacter cloacae and Kineococcus radiotolerans were diagnosed phenotypically and molecularly. The diagnosis was confirmed by analyzing the nitrogen bases sequence of the DNA of the 16S rRNA gene. It was recorded in the National Center Biotechnology Information(NCBI) with the numbers MN310027.1 and KT216573.1 respectively, these isolates were activated and tested their efficiency as a bio-stimulant by testing their ability to dissolve insoluble phosphate compounds and produce indole acetic acid and chelating compounds, the results showed the ability of all isolates to produce indole acetic acid (IAA), chelating compounds, and solubility of phosphates, E. cloacae isolate outperformed K. radiotolerans isolates in these parameters, as it gave E. coloaca solubilization of phosphate and IAA production of 40.3 mg p L-1 and 11.2 µg ml-1 respectively, and it showed a high output of the chelating compounds compared to the treatment inoculated with K. radiotolerans, which gave 27.20 mg p L-1 and 7.21 µg ml-1, and medium production of iron chelating compounds, the results also showed the superiority of the inoculated treatments over the uninoculated treatments in the percentage of germination, the speed of germination, the length of tomato seedlings, the dry weight of the Shoot and root parts and the number of leaves, and the results showed the superiority of the inoculated treatment with E. cloacae significantly on K. radiotolerans isolate.