Effects of different pretreatment time of onion before Agrobacterium infection.

Note: three repeat samples for each treatment were investigated by observing ten 2 mm2 epidermal areas of each sample. Each efficiency value represents the mean of transformation efficiencies of thirty replicates of 2 mm2 epidermal areas from three samples (the percentage of positive cells in total cells per unit area), and the standard errors were calculated by using Excel. Different capital and lowercase letters within the same column exhibit significant difference at the 1% and 5% probability level according to the Duncan test of SPSS 10.0 statistic analysis.