To obtain virus- free healthy plants from a diseased one by tissue culture technique, which part/parts of the diseased plant will be taken?

Even if the plant is infected with a virus, the meristem (apical and axillary) is free of virus. Hence, one can remove the meristem and grow it in vitro to obtain virus-free plants. Scientists have succeeded in culturing meristems of banana, sugarcane, potato, etc.