Plant Tissue Cultures of Juniperus virginiana.

Callus cultures of Juniperus virginiana L. (varieties 'Hetzii', 'Glauca', 'Grey Owl') were derived from fresh leaves of garden-grown trees on Schenk and Hildebrandt medium supplemented with 3.0 mg/L of α-naphthaleneacetic acid, 0.2 mg/L of kinetin and 15 mg/L of ascorbic acid. The growth characteristics of one-year-old and two-years-old cultures were determined. The maximum biomass in all varieties was achieved on the 35th day of the cultivation period. The increase in fresh weights of two-years-old callus cultures, when compared with one-year-old callus cultures, was as follows: variety 'Hetzii' by 25%, variety 'Glauca' by 29% and variety 'Grey Owl' by 49%. J. virginiana suspension cultures (varieties 'Hetzii', 'Glauca', 'Grey Owl') were derived from two-years-old callus cultures on Schenk and Hildebrandt medium supplemented with 3.0 mg/L of α-naphthaleneacetic acid, 0.2 mg/L of kinetin and 15 mg/L of ascorbic acid. The maximum biomass of all varieties was found on the 21st day of the cultivation period. These results indicate that a sub-cultivation interval of 35 days for callus cultures and of 21st days for suspension cultures can be recommended. The callus and suspension cultures of J. virginiana of the variety 'Glauca' have the best survivability and thus provide the most biomass.