Twenty nine strains of Mesorhizobium ciceri were screened for indigenous plasmids and cured derivatives were obtained in fourteen parent strains. Based on plasmid profile, 1 to 3 plasmids were observed in all the M. ciceri strains and these were clubbed into 3 groups (Group 1-3). The molecular size of plasmids in all the strains ranged from 228-259 kbp. Curing of plasmid (s) was achieved with triple treatment of ethidium bromide (2 µg/ml), acridine orange (1 µg/ml) and high temperature (38 °C). Antibiotic resistance pattern of the parent strains and their cured derivatives was similar, indicating that these were true derivatives. The production of exopolysaccharide (EPS) in cured strains was less than fifty per cent of parent strains. The symbiotic effectivity of all the parent strains was higher than that of their cured derivatives.
Plasmids, Mesorhizobium ciceri, curing, exopolysaccharide, symbiotic effectivity, acridine orange, ethidium bromide, acetylene reducing activity
© The Author(s) 2014. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License which permits unrestricted use, sharing, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.