Biotechnology Centre, Indian Agricultural Research Institute, New Delhi-110012, India.
1Division of Microbiology, I.A.R.I., New Delhi-110012.
2C.S.I.R., Rafi Marg, New Delhi-110001.
A symbiotic mutant of Rhizobium meliloti Rmd438 (sxf C:: Tn5) which was phage resistant against RMP64, failed to utilize galactose as carbon source as reported earlier (21). The Bg/II gene bank of wild type R. meliloti was mobilized into Rmd438 and a clone pSP676 which complemented for phage sensitivity was isolated. In order to characterize this clone, a Bg/II and EcoRI map was constructed. The insert of 13.2 kb had three Bg/II fragments of 4.0, 3.6 and 5.6 kb in this order. All three fragments were subcloned on the vector pRK290 and mobilized into Sxf-mutants. The complementation for phage sensitivity, symbiosis and galactose utilization properties are discussed.
sxf C locus, cloning, symbiosis, phage sensitivity, Rhizobium meliloti.
