Abstract: Different concentrations of 2,4-D, KT and NAA were able to influence the plating efficiency (PE) of single cells of Cathamus tinctorius. The best combination of these three hormones for the growth of single cells was 2.0, 0.3 and 0.5 mg/l, respectively. The PE was obviously different as cells came from different generations of suspension subculture and the third generation of suspension culture cells, had the best PE which 8.5 times as high as that of the first generation of suspension culture cells. Single cell growth in condition medium or in solid-liquid dual layer culture was better than in normal plate culture. The PE of single cell clones in condition culture was 3.6 times as high as in normal plate culture. The PE of single cell clones in solid-liquid dual layer culture was 4.7 times as high as in normal plate culture. Many clones from single cells were set up. Different growth rates were observed in different single-cell clones. The lowest growth rate in these clones was 3.08 g/g/35 days, the highest growth rate in these clones was 23.33 g/g/35 days.

Key words: Cathamus tinctorius, Single-cell clone, Plating efficiency, Conditional culture, Solid-liquid dual layerl culture