Iw. Sul et Ss. Korban, EFFECT OF DIFFERENT CYTOKININS ON AXILLARY SHOOT PROLIFERATION AND ELONGATION OF SEVERAL GENOTYPES OF SEQUOIA SEMPERVIRENS, In vitro cellular & developmental biology. Plant, 30P(3), 1994, pp. 131-135
Five genotypes of Sequoia sempervirens were cultured in vitro. Stem se
gments of greenhouse-grown plants were disinfested and grown on a Welt
er and Skoog (WS) medium without growth regulators for 4 wk. Newly dev
eloping shoots from axillary buds were then subcultured onto fresh med
ia containing several different cytokinins at a concentration of 5 mu
M each per treatment. The following cytokinin treatments were used: be
nzyladenine (BA), BA plus adenine hemisulfate, N-benzyl-9(2-tetrahydro
pyranyl) adenine (BPA), N6-[2-Isopentenyl]adenine (2ip), kinetin, thid
iazuron (TDZ), and zeatin. Each genotype responded differently to test
ed cytokinins. The use of zeatin resulted in the highest number of sho
ots and the longest shoots for three genotypes of S. sempervirens. In
another experiment, shoots from three genotypes were grown on the same
basal medium described above and supplemented with zeatin at six diff
erent concentrations (2.5, 5, 10, 15, 20, and 30 mu M). For all zeatin
concentrations, significant differences among genotypes for shoot pro
liferation were observed. When all five genotypes were grown under thr
ee concentrations of zeatin (5, 10, and 15 mu M), differences among ge
notypes were observed for both shoot proliferation and shoot length. T
he influence of the culture medium on the overall micropropagation pro
tocol of S. sempervirens is discussed.