A. Akula et Wa. Dodd, DIRECT SOMATIC EMBRYOGENESIS IN A SELECTED TEA CLONE, TRI-2025 (CAMELLIA-SINENSIS (L.) KUNTZE,O.) FROM NODAL EXPLANTS, Plant cell reports, 17(10), 1998, pp. 804-809
An efficient method for the in vitro propagation of a tea (Camellia si
nensis (L) O. Kuntze) clone, 'TRI-2025', from somatic embryos is descr
ibed. This technique involves two phases; the induction of adventitiou
s buds from nodal cuttings followed by the development of somatic embr
yos. Single nodal cuttings were excised from 1-year-old in vitro axeni
c cultures and inoculated on MS medium with different combinations of
IBA/BAP/GA(3). Induction of multiple shoots from nodal explants occurr
ed on MS medium with 0.5 mg l(-1) BAP, 0.1 mg l(-1) IBA and 0.0 mg l(-
1) GA, within 6 weeks of incubation. The cultures with multiple shoots
were transferred to fresh medium, incubated for 120 days and transfer
red to MS medium with half-strength macro nutrients, full-strength mic
ronutrients and vitamins and no growth regulator. The direct induction
of somatic embryos without callus formation occurred on this medium a
t 60% frequency within 4 weeks. The production of embryos continued up
on transfer of the cultures to fresh medium and a four- to eightfold m
ultiplication rate was obtained during each 6-week culture cycle. The
plantlets from these embryos were acclimatised with a 90% success rate
. All plants were vigorous and hardy, with well-developed tap-root sys
tems.