Document Type : Research Paper
Authors
1
MSc Student, Department of Plant Protection, Faculty of Agriculture, Islamic Azad University, Varamin-Pishva Branch, Varamin, Iran
2
Professor, Department of Plant Protection, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran
3
Assistant Professor, Department of Plant Protection, Faculty of Agriculture, Islamic Azad University, Varamin-Pishva Branch, Varamin, Iran
Abstract
Plant rhizospheric microbes are diverse microorganisms which can be employed to assist plant health. Root exodates of potato as an edible plant can support many benefit bacteria, especially Bacillus spp. Awareness about diversity and phylogenetic of these bacteria has great potential to apply them as a plant growth promoting and antagonists against the root pathogens. For this purpose, healthy potato plants rhizospher samples were collected from Hamedan province and a total of 43 Gram and catalase positive bacterial strains were isolated. Antagonistic activity of the isolated strains towards Pectobacterium carotovorum subsp. carotovorum (Pcc) were evaluated on NA medium using dual culture in a complete randomized design, inhibition zone was recorded and analyzed. Results indicated that 11 strains were able to produce inhibitory zone against Pcc and showed significant differences at 1% level. Strain B57 with 3.16 centimeters and strain B4 with 1.16 centimeters inhibition zone, had the highest and lowest inhibitory respectively. Based on the phenotypic features antagonistic Bacillus strains were belongs to Bacillus subtilis, B. cereus and B. pumilus. Results of 16S rDNA gene sequencing from these three Bacillus species verified the results of phenotypic feature characterization. Phylogenetic position of the tested Bacillus strains showed that strain B34 clustered with 1000 bootstraps as B. cereus, strain B7 with 1000 bootstraps as B. subtilis and strain B57 with 1000 bootstraps as B. pumilus. Accession number for the 16S rDNA gene sequences of B7, B34 and B 57 Bacillus strains in NCBI are MG654658, MG654659 and MG654660 respectively. According to the litrature, one of the microbial factors that in the rhizosphere of potato plants prevents the establishment of pathogens is the diversity of bacilli in this area. Numerous studies have reported the role of rhizosphere bacilli in reducing root diseases of various plants.
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