Some factors which affect the in vitro propagation of wild pear (Pyrus
syrica) were studied, Successful shoot proliferation was obtained on
Murashige and Skoog medium supplemented with 1.5-2.0 mg l(-1) benzyl a
denine. Shoot height decreased to 1.8-1.6 cm and 1.3 cm with benzyl ad
enine (1.5-2.0 mg l(-1)) and zeatin (1.0-2.0 mg l(-1)), respectively.
Benzyi adenine (at 2.0 mg l(-1)) and zeatin (at 1.5-2.0 mg l(-1))enhan
ced callus formation. Indole butyric acid, indole acetic acid and naph
thalene acetic acid induced in vitro rooting and a maximum of 72% root
ing was achieved at 3.0 mg l(-1) indole acetic acid. Neither activated
charcoal nor polyvinylpyrrolidone influenced in vitro rooting. Ex vit
ro rooting was unsuccessful when treating shoot microcuttings with 0.0
, 5.0, 10.0, or 15.0 mg l(-1) indole butyric acid, indole acetic acid,
or naphthalene acetic acid for 1 h and grown under intermittent water
mist. An average of 95% survival was achieved when rooted microshoots
were acclimatized under glass or plastic covers using intermittent mi
st in the greenhouse. (C) 1997 Published by Elsevier Science B.V.