TISSUE-CULTURE OF TEA PLANT - DIFFERENTIATION, PLOIDY LEVEL, AND FORMATION OF PHENOLIC-COMPOUNDS

The formation of flavans and total soluble phenolic compounds was inve stigated in three strains of callus tissues derived from tea plant (Ca mellia sinensis L.) stems with their morphological and cytogenetical t raits. The three strains differed among themselves in the conditions f or callus induction and in the total duration of tissue subculturing. In particular, strain ChS-1-1, cultivated for 20 years, considerably d iffered from the other two strains in its low capacity to produce phen olic compounds, low mitotic activity, the occurrence of single trachei d elements, and in the predomination of tetraploid cells in the cell p opulation. In contrast, strains ChS-2 (cultivated for 15 years) and Ch S-1-2 (a spontaneously changed callus tissue of strain ChS-1-1 maintai ned in culture for a further 12 years), with diploid cells prevailing, accumulated a considerable quantity of phenolic compounds, manifested a higher mitotic activity, and contained numerous tracheid elements. It is suggested that the rate of phenolic compound formation in tea pl ant callus cultures depends primarily on the extent of tissue differen tiation and the presence of diploid cells characteristic of the intact plant, rather than on the condition of callus initiation and the dura tion of tissue growth on subculture.