Leaf fragments from in vitro-grown plants derived from theanther cultures were chopped with a razor blade in Lysisbuffer (15 mmol/l Tris, 2 mmol/l Na2EDTA, 0.5 mmol/l spermine,80 mmol/l KCl, 20 mmol/l NaCl, and 0.1% (v/v) Triton X-100; pH7.5) to release the nuclei