MICROPROPAGATION AND REGENERATION OF ENGLISH ELM, ULMUS-PROCERA SALISBURY

Rapidly elongating shoot tips from a clone of the English elm, Ulmus procera SR4, were taken in early summer and sterilized by sodium hypochlorite treatment before transfer to three different proliferation media. Proliferating shoot cultures readily established on Driver and Kuniyuki Walnut medium (DKW), but failed to establish on either Murashige and Skoog-based medium, or Woody Plant medium. On DKW medium 3-5 shoots were produced per 3 week subculture period or up to 20 more shoots from the stem base callus, if this was subcultured separately. Excised leaves regenerated shoots readily from the petiole region on standard DKW medium after 3-4 weeks, and this was unaffected by the antibiotic cefotaxime, but prevented by concentrations of kanamycin above 50 mg dm-3. U. procera SR4, a well characterized clonal tree of known habit and high timber quality is, therefore, amenable to the procedures necessary for genetic manipulation.