Tissue culture of C. officinalis was reproducible for six subcultures, with slight changes in shoot height (4.2-5.4 cm). Plantlets cultured in MS½N produced a maximum of two shoots per explant (Figure 1 and Table 3). Cytokinins improved the production of C. officinalis plantlets when compared to control. TDZ was less effective compared to BAP because shoots from any TDZ concentration failed to elongate (Figure 2),confirming studies where TDZ inhibits shoot elongation
(LEDBETTER; PREECE, 2004). Plantlets from control medium and medium supplemented with BAP reached a height of 4.5 cm and 3.3 cm, respectively (Table 3).Forty-five-day-old plantlets developed in TDZ media
were transferred to a medium without growth regulators to which included the absence of roots in addition to
reduced shoot height and leaf size. Each plantlet obtained from medium supplemented with BAP provided about
three explants to initiate new subcultures. This hormone promoted the greatest shoot formation, and the addition of
BAP induced a high production of new plants per year.elongate. Results such as reduced height and vitrification
were verified for plantlets cultured with additional TDZ. Four subcultures intercalated by four transfers were
required for the TDZ treatments, all within the one-year period. After subculture in 0.8 mg L-1 TDZ, the greatest
percentage of shoot elongation in control medium was 59%,
reaching a maximum height of 5.1 cm (Table 2). Plantlets
from TDZ media also showed residual effects for two
consecutive subcultures in MS½N (control medium),