In the present experiment adventitious buds were induced on excised co
tyledon segments and embryo explants of Juniperus excelsa on both Erik
sson (1965) and Murashige and Skoog (1962) basal media containing eith
er 0.5 or 1 mg l(-1) BAP (6-benzylaminopurine) with or without NAA. Wh
en 0.02 mg l(-1) NAA was added to Eriksson basal medium containing 0.5
mg l(-1) BAP as many as 92 adventitious shoots were formed per cotyle
don segment. Embryo explants showed the best response when the same co
ncentration of NAA was added to Murashige and Skoog medium containing
1 mg l(-1) BAP. The presence of NAA in Murashige and Skoog basal mediu
m suppressed the morphogenetic response of cotyledon explants and succ
essive growth of the buds. When the proliferated explants with numerou
s scale-like organs were transferred to respective basal media contain
ing neither BAP nor NAA and when all explants with overcrowded propagu
les were divided into two or more sections, the growth of the propagul
es was further stimulated. Better rooting of adventitious shoots was a
chieved when shoots were pre-treated with IBA (1 mg l(-1)) and NAA (0.
5 mg l(-1))or activated charcoal (1% w/v) for three weeks and incubate
d in a covered seed tray filled with non-sterile compost for four mont
hs. Untreated shoots also rooted after four months when maintained on
the same basal medium. These aseptically rooted shoots needed more car
eful acclimatisation. (C) 1997 Elsevier Science B.V.