10.22376/ijpbs.2019.10.1.p1-12 Volume 4 Issue 4 2013 (October - December) Optimization of co-cultivation parameters during lessThan i greaterThan Agrobacterium lessThan /i greaterThan –mediated transformation to lessThan i greaterThan Cissampelos pareira lessThan /i greaterThan evaluated were bacterial density, infection period, wounding and pre-culture of explants, acetosyringone (AS) concentration and co-cultivation temperature. Optimized parameters resulted in high transformation efficiency at transient GUS expression were as follows; lessThan i greaterThan Agrobacterium tumefaciens lessThan /i greaterThan growth phase of A lessThan sub greaterThan 600nm lessThan /sub greaterThan 0.17, infection period of 30 min, addition of acetosyringone (AS) in co-cultivation medium (50µM) and in bacterial growth culture (800µM) and co-cultivation temperature of 25 lessThan sup greaterThan o lessThan /sup greaterThan C. Higher bacterial density resulted in more transformation efficiency, but also higher necrosis in the explants. Dilution of bacterial suspension reduced necrosis in explants and resulted in higher transformation. The transformation efficiency was increased 6 fold when the infection process was carried out with acetosyringone in co-cultivation medium (50µM) and in bacterial culture (800µM).Our studies proved that among the optimized conditions; the concentration of acetosyringone was the critical parameter during co-cultivation process in lessThan i greaterThan Agrobacterium lessThan /i greaterThan mediated transformation. MUSTRAHALLY RAJAGOPAL AND BATHULA SRINIVAS Agrobacterium tumefaciens, Cissampelos pareira, gus gene. 1111-1128